Pile Cap re-distribution: Hi Ahmad, If the column vertical reaction remains on the position of the original 300x300 stump, then increasing the stump width will not significantly alter the position of the resultant vertical force on to the pile cap, I am afraid! You have 2 choices-...

Civil Engineering: roof slab design, RC Roof Slab Design

RC Roof Slab Design: Hi Ashraf, This is too general a question, but this may assist you(RC roof design is similar to floor design, but with reduced live loading): http://www.scribd.com/doc/19184820/Economic-Long-Span-Concrete-Floor-Slabs http://en.allexperts.com/q/Civil-Engineering-1357/roof-slab-reinforment-details.htm...

Civil Engineering: Seeking project guidance, Raft FEA analysis & Design

Raft FEA analysis & Design: Hi Arnab, I am not familiar with ANSYS, but most FEA software work on the principle of beam on elastic foundations (simulated by spring supports), and normally you need to do iterative runs of the model to get upper-bound and lower-bound results in terms...

Civil Engineering: Shear design for slab in SAFE, SAFE Slab Design for Shear

SAFE Slab Design for Shear: Hi Karkin, If you are using SAFE v12, and if you invoked Run Analysis & Design (instead of just Run Analysis), then the output does have all details for shear values and rebar requirements. That way you will be able to ascertain if the output is correct...

Civil Engineering: Steel shuttering Design, structural steelwork, wet concrete

structural steelwork, wet concrete, composite design: Hi Bala, This can be designed using the locally applicable standard on structural steelwork, but when analysing the forces, you need to take account of pressures from wet concrete as well as construction related loading (such as men, equipment, etc). I...

Civil Engineering: steel column footing, steel column, axial load

steel column, axial load, baseplate: Hi Ravi, This depends on the detailing of the joint- if it is a true pin joint, then the answer is no; however, if it is a baseplate with 2 bolts, then you should apply a minimum moment equal to maximum axial load X lever arm between centre of column and...

Civil Engineering: Tie Beams, Tie or Plinth Beams

Tie or Plinth Beams: Hi Kaushik, This is difficult to answer as it depends on various aspects. However, generally the tops of tie (gound) beams can be just below the natural gound level. You can span primary beams between columns and then have secondary ones (below walls) spanning...

Civil Engineering: Transverse Reinforcement Critieras for Simply Supported Flexural Members, Lateral Rebar in Flexural Members

Lateral Rebar in Flexural Members: Hi Umar, I am not sure which 4 criteria you speak of, but perhaps you mean lateral reinforcement? Lateral reinforcement in ACI-318 is required for compression rebar in order to stop this buckling. So, if your SS beam is only singly reinforced (i.e. top...

Civil Engineering: Any way to obtain a licence certificate in Civil Engg., building constructions, layout drawings

building constructions, layout drawings, boundary markers: Hi Vinod, That depends on how the site boundary markers are placed and what distances are shown on the layout drawings between the markings and the corners of the building. The centre-line also depends on whether the building is symmetrical or not...

Civil Engineering: Cantilever Retaining Wall, RC Retaining Wall

RC Retaining Wall: Hi Abhishek, This sounds like a homework question, which you really should learn the baics of yourself before answering. The bending moment depends on afew variables such type and density of soil retained, ground water table, whether there is surcharge,...

Civil Engineering: Civil Structural Engineer, Residential Building Estimate

Residential Building Estimate: Hi Amit, Fot calculating loads, you need to assess the self (dead) weight of the structure by calculating the volume and multiplying with the density, and you need to apply the imposed (live) loads in accordance with usage and the applicable standards/codes....

Civil Engineering: Concrete and steel columns, Steel/Concrete combined construction

Steel/Concrete combined construction: Hi Ravi, You can do a proper analysis so long as you define the section properties correctly and you take care about detailing the joints in such a way that the assumed fixity conditions are realised or buildable. For examle, you can cast a steel plate...

Civil Engineering: Different questions, ETABS Analysis Manual Checks

ETABS Analysis Manual Checks: Hi Umar, If you are asking about ETABS, there will be no diaphragm in a pitched roof- you just rely on the roof to brace itself and to transmit loads on to the beams or walls. For lateral wind loading, you will need to manually work it out and apply it...

Civil Engineering: dynamic seismic load, ETABS Dynamic Analysis

ETABS Dynamic Analysis: Hi Ravi, Not automatically- you have to use the RSA mode and then input the appropriate data in order to do dynamic analysis. The help menu has more info, as pasted below: ******************** Define Response Spectrum Case Form: Define Response Spectra,...

Civil Engineering: expansion joint provision for large water retaining structure, Early Age Concrete Cracking

Early Age Concrete Cracking: Jonathan, Basically this design takes account of the prevailing weather conditions, the shape/size/support conditions of the structure (i.e. what restraint there is to shrinkage, the concrete mix & compaction, the curing methods and the quantity and distribution...

Civil Engineering: Final Year project topics, final year project, final year projects

final year project, final year projects, highway engineering: Hi Yemi, I am not an expert in highway/transportation, but my answer below may give you some ideas relevant to your location: http://en.allexperts.com/q/Civil-Engineering-1357/2009/11/Final-Year-project-Kenya.htm As for research on other construction...

Civil Engineering: Foundation on Fill, floor slabs, air gap

floor slabs, air gap, ground settlement: Hi Jang, I am not an expert in geotechnics, nor have you given enough data. The answers depend on the properties of the soil, degree of compaction, etc. You need to do some site investigations in order to get the properties needed to do an assessment. ...

Civil Engineering: Mass Vs. Weight in ETABS, storage areas, warehouses

Civil Engineering: Mass Vs. Weight in ETABS, storage areas, warehouses, ubc

Civil Engineering: Support under plinth beams

Civil Engineering: Support under plinth beams

Civil Engineering: final year project, yr student, final year project

yr student, final year project, suitable project: Hi Dayveed, I (and fellow experts) have answered this question many times before- please browse my past answers using the keywords: Final year project, Projects, Topics One such example is: http://en.allexperts.com/q/Civil-Engineering-1357/2009/12/final-year-project-3.ht...

Civil Engineering: Green Buildings, Green Buildings

Green Buildings: Hi Siva, Yes, this is a hot topic so a good one to pursue. If you do a search on Google.com, you will find lots of material, such as ones below: http://www.igbc.in/site/igbc/index.jsp http://www.usgbc.org/ http://www.ukgbc.org/site/home http://www.worldgbc.org/...

Civil Engineering: Mass Vs. Weight in ETABS, response spectrum, seismic load

response spectrum, seismic load, etabs: Hi Arman, The discrepancy could be due to several reasons, such as definition of mass source (menu Define Mass Source, where you should have the dead load plus 25% of live load), whether you have sufficient modes in order to capture at least 90% of the...

Civil Engineering: Raft pile foundation design, Leaning Towers Foundations

Leaning Towers Foundations: Hi Murid, This then depends on the pile capacities vs length and diameter. If you can cater for all loading without piles goind down into the pancone clay, then you can use piles. If not, the alternative is to use a wide circular strip footing, which...

Civil Engineering: Rebar per cubic meter in RCC, Rebar Density in Concrete

Rebar Density in Concrete: Hi Amith, This really depends on what part of the structure your are talking about, and can vary from about 60 kg/m3 for rafts to 250 kg/m3 for beams. On average for a building you can assume between 80 and 120 kg/m3 depending on geometry/size/spans and...

Civil Engineering: Rigid foundations, Rigid Foundation

Rigid Foundation: Hi Ali, This is based on engineering judgement and depends partly on what the supporting strata is and also on what the loaded area is- e.g., is it a single column load or continuous walls etc, which may result in the foundation becoming more rigid. ...

Civil Engineering: raft foundation, Raft Foundation Design

Raft Foundation Design: Hi Gaurang, This is quite complex, depending on soil conditions and how the loading is applied. A raft foundation is designed like an upside-down flat slab, with the upwards subgrade reactions being equal and opposite to the self weight of the raft,...

Civil Engineering: SAP 2000, Isolated Footing Design

Isolated Footing Design: Hi Sajad, For isolated footings, use SAP 2000 only if you want to do detailed FEA analysis, otherwise it is best/easier to use either hand calculations or spreadsheets readily available, such as this website: http://www.civl.port.ac.uk/rcc2000/ ...

Civil Engineering: Staggered reinforcement in raft, raft foundation, stress concentrations

raft foundation, stress concentrations, rebar: Hi Issa, The main advantage of staggered rebar lapping is to avoid rebar congestion at localised zones and also to avoid stress concentrations in the concrete (to transfer bond) to only one zone- by staggering the laps, the stresses are spread over a larger...

Civil Engineering: Strap Footing, Combined Footing

Combined Footing: Hi Gilbert, This depends on the relative stiffnesses of the sub-grade, the pad footings and the strap beam. It will only really work as a combined footing if the strap beam is as stiff in the vertical plane as the pad footings. Also, you can frame the strap...

Civil Engineering: Structural enginering how to design piles caps which can support more than five piles, Multiple Pile Cap Design

Multiple Pile Cap Design: Hi Taddesse, Actually you can design a pile cap with up to 5 piles (5th one directly under the column in the middle) using traditional methods. However, for anything more than 5 piles, you end up having pile-grouping effects and also for the design of...

Civil Engineering: Structural Software, sofware packages, e tabs

sofware packages, e tabs, structural software: Hi Harshalsab, All the sofware packages you have listed are merely tools- if the input is incorrect the ouput is also incorrect. All 3 are excellent packages and can be used for buildings and structures well over 100m high, with reasonably accurate results....

Civil Engineering: Support under plinth beams, Blinding for plinth or ground beams

Blinding for plinth or ground beams: Hi Saad, If by PCC you mean a 50 to 75mm thick layer of weak concrete, then this is what we call blinding and it is there merely to give a flat surface to place rebar and spacers and formwork so that the beam does not get deformed or contaminated by the...

Civil Engineering: shear pins, RC Shear Studs

RC Shear Studs: Hi Sudha, This is not a terminology I have come across in RC, apart possibly from pre-cast sections connections, where a steel shear pin would be used to retain a joint. Normally shear pins are used in steelwork much more. There are proprietory flat-slab...

Civil Engineering: shear wall, Soft Story

Soft Story: Hi Hashmi, I presume you mean that the shear wall will not continue down to ground floor and the foundations? If so, the base shear will remain more or less the same (as without the walls), but it will need to be resisted by the columns and beams alone...

Civil Engineering: steel cantilever shelter for 3 cars, Car Port Design

Car Port Design: Hi Mi, In Mauritius, as you will not have any snow loading, the main loading will be self-weight, some nominal live loading for maintenance (say 0.25 kN/m2) and wind loading, for which the uplift will probably be the most prominent. You will also need to...

Civil Engineering: structural analysis & design, load combinations, seismic loading

load combinations, seismic loading, load factors: Hi Mohammed, I think you need to follow the recommendations of the code you are using, whether it is BS 8110, Eurocode or UBC or IBC- these will guide you on the load factors and combinations. Usually for seismic loading, the combination is 1.0 x all dead...

Civil Engineering: structural Engg, steel trusses, steel truss

steel trusses, steel truss, column grid: Hi Sajid, This depends on the live loading and also usage of the floor (defelction criteria). You may find that a slightly deeper beam (say 750mm) will result in much less rebar and so will be more economical overall). Also, the 200mm slab may not meet...

Civil Engineering: structural engineer, Thick Concrete Casting

Thick Concrete Casting: Hi Hamdy, The main control measures are: 1. Use up to 60% cement replacement(pozzalana, pulverised fly ash, etc). 2. Keep aggregates wet or chilled and covered from direct sunlight. 3. Use ice in the mixing water. 4. Cast the raft in cooler season...

Civil Engineering: structure, Robustness

Robustness: Hi Hashmi, Robustness is defined as the inherent property of a structure so that it does not suffer from disproportionate collapse. For example, if one column is knocked out by a car at ground level, the whole building should not collapse. Robustness requirements...

Civil Engineering: Thickness of PT Slab, lateral stiffness, flat slabs

lateral stiffness, flat slabs, slab thickness: Hi Marcus, If your Adapt design is showing thickness and rebar, you also ned to take account of the costs of the strands and the actual prestressing or post-tensiong activities/costs. If your building is high-rise, and seismic loading is significant,...

Civil Engineering: Water flowing in hole in concrete floor, Basement leakage

Basement leakage: Hi Steve, I am not an expert in this, nor do I have enough info on the building/surroundings etc, but have you tried to plug the pipe with a large cork or wooden plug? If that stops the bulk of the water intake, you may be able to use some form of sealant...

Civil Engineering: blinding concrete, Blinding and Ground water pressure

Blinding and Ground water pressure: Hi Maher, Blinding concrete is required just to form a level base for the waterproofing layer and for placing rebar before casting the raft, so it is not meant to be water-tight by itself. Therefore there should be no problem in casting this in bays with...

Civil Engineering: CHS Base Plate, axial force, axial load

axial force, axial load, pipe size: Hi DC, In that case, you just divide the axial load by the area of the base plate (excluding hole) and check for local bending and contact pressure stresses. The plate will need to be thick enough to sustain the forces/stresses without bending too much,...

Civil Engineering: civil engineering, Final Year Projects

Final Year Projects: Hi Thirumavalavan, You have not mentioned which aspects of civil engineering interest you most, but if this is in structures, you could consider: 1. High strength concrete 2. Durability of concrete. 3. Optimisation of structures. 4. Punching shear...

Civil Engineering: Design Review Rates, institute of engineers, professional fees

institute of engineers, professional fees, man hours: Hi Stanley, It has been over 10 years since I last worked in Kenya, so I regret that I do not have any idea of current rates. In Europe, depending on seniority/complexity of work, the hourly rate can vary between Euros 30 to 80, so possibly in Kenya you...

Civil Engineering: deck slab thickness, slab thickness, bridge deck

slab thickness, bridge deck, self weight: Hi Fairul, The short answer is yes, it should be OK. You can work out the additional self weight and see what %age it adds to the total loading and this will probably be minimal. In any case, you can always beef up the hogging rebar a bit to make up for...

Civil Engineering: dissertation titles, Final Year Projects

Final Year Projects: Hi Joslyn, I think your subject matter is vry topical and could certainly be an interesting one to pursue. I note on Google that you can find several references to this topic. Best of luck! If you want some further ideas for concrete, please browse my earlier...

Civil Engineering: FEA for slab and beam structures, FEA Slabs and Beams

FEA Slabs and Beams: Hi Denis, For modelling floors and beams, there are several good software packages available, such as Staad.Pro, ETABS, SAFE, etc. If the input is correct, then the output should be correct but I always do some hand calculations to verify that the results...

Civil Engineering: Footing Depth, Foundation Thickness

Foundation Thickness: Hi Hossain, If you mean thickness, basically you need to work out the plan area and shape of the footing based on allowable pressure, then check the maximum shear near or around the column- this will determine the optimal depth of the footing. As a rule,...

Civil Engineering: Foundation in mass concrete, mass concrete, embedment

mass concrete, embedment, power house: Hi Siddharth, This depends on whether the columns have much moment at the base and whether the mass concrete can sustain the stresses due to both moment and gravity loading (i.e. contact pressure under footprint of column). If the contact pressures are...

Civil Engineering: long span trusses, roof trusses, earthquake loading

roof trusses, earthquake loading, gravity load: Hi Nordz, You are correct that some idealisation is not accurate- such as assuming all joints in trusses as being pinned. In large span structures, where the struts and ties are made of heavy sections, there will be local bending stresses near the nodes...

Civil Engineering: Mathematics required in civil engg.??, Maths for structural engineers

Maths for structural engineers: Hi Anuj, I know how you feel because I felt the same. You will be pleased to know that you do not need to be a guru in maths in order to be a good structural engineer. Just knowing the basics of maths, physics, statics/mechanics, etc will take you a long...

Civil Engineering: modelling in etabs, edge beams, etabs

edge beams, etabs, diaphragm: Hi Waliur, This is very difficult to answer without reviewing the model. One thing you should do is use semi-rigid diaphragm and also ensure that line constraints are invoked and auto-mesh is invoked for the slabs. Then re-run the model and see if that...

Civil Engineering: raft foundation, soil structure interaction, raft foundation

soil structure interaction, raft foundation, interaction analysis: Hi Sudip, I cannot send you a design example, but if you are asking about the principles, then basically you need the full ground investigation and then do a soil-structure interaction analysis that takes into account the relative stiffness of the building...

Civil Engineering: Self supporting helical staircases, Helical Stairs

Helical Stairs: Hi Solomon, This is quite complicated and normally one would use either empherical formulae/tables, as per the popular RC Designer s Manual by Reynolds & Steedman, or else use a 3-D analyis program, such as STAAD.Pro. The following websites may also...

Civil Engineering: Tension lap and compression lap, Rebar Splices / Lap lengths

Rebar Splices / Lap lengths: Hi Yong, This is the length of over-lap required for rebar in order to safely transfer the stress/load for one bar to the other. The lap length depends on various factors such as size and type of bar (ribbed, round, etc), the spacing of bars (single or...

Civil Engineering: EC 8 Response Spectrum -ETABS 9.6, response spectrum, ec 8

response spectrum, ec 8, spectrum analysis: Hi Muhammad, It is very difficult to advise you without looking at the model in detail. One reason that you could have low base shear is that your mass source is not defined properly? Please check this and see if that solves the problem (the ETABS help...

Civil Engineering: EC 8 Response Spectrum -ETABS 9.6, mass participation, modal analysis

Civil Engineering: EC 8 Response Spectrum -ETABS 9.6, mass participation, modal analysis, modes of vibration

Civil Engineering: new technologies in civil engg, New Technologies in structures

New Technologies in structures: Hi Hinal, I am not an expert in environment or traffic, but some new technologies in structures are: 1. Ultra-high strength concrete (80 mpa plus) 2. Self-compacting concrete 3. Twin-wall precast system 4. Modern methods of construction 5. Zero-carbon...

Civil Engineering: project topis, hiways, civil engg

hiways, civil engg, final year project: Hi Krishna, I (and fellow experts) have answered this question many times before- please browse my past answers using the keywords: Final year project, Projects, Topics One such example is: http://en.allexperts.com/q/Civil-Engineering-1357/2009/12/final-year-project-3.h......

Civil Engineering: Structural Steelwork Connections, handbook of structural steel connection design and details, steel structures

handbook of structural steel connection design and details, steel structures, generousity: Hi Ananta, Joinery is a terminology used mainly in timber connections/carpentry. For steel structures, this is called connections or joints. Steel Designers Manual has a lot of details. Also, check these sites: http://sydney.edu.au/engineering/civil/courses/civl3206/economical_structural_steelwork.pdf...

Civil Engineering: soil test, specific gravity test, bituminous mixtures

specific gravity test, bituminous mixtures, road constructions: The moisture condition test is a method of quickly assessing the suitability of earthwork materials for use as fill, i.e. the soil / fill is at a moisture content such that it can be fully compacted by the appropriate plant. The moisture condition test...

Civil Engineering: alternative energy, Alternative Energy Subjects

Alternative Energy Subjects: Hi Noon, I am not an expert in this field, but I know that this is a very topical subject and one that is worthy of studying. I would imagine that the subjects that would be useful for you would be alternative materials, fluid dynamics (for wind/wave energy),...

Civil Engineering: Beam span & stress, max stress, cross section

max stress, cross section, span: Hi Sean, I don t know what a Stala beam is, but basically the maximum any beam can span is usually limited by either deflection or ultimate stress, both of which depend on the loading as well as the section properties. You can work out the moment and shear...

Civil Engineering: Bill of Quantities, BOQs

BOQs: Hi Donald, So long as the quantities are measured and described in accordance with the norms, there is no difference! In fact, as an Engineer, I have in the past prepared some BOQ s. And for most civil engineering projects the BOQ s are prepared by engineers...

Civil Engineering: Bridge and Culvert, continuous construction, roof deck

continuous construction, roof deck, hi john: Hi John, A bridge is normally for longer spans and the deck is usually jointed with the piers/supports with either a hinged or a sliding joint. A culvert is for shorter spans and is either circular or rectangular and in the latter case the roof (deck for...

Civil Engineering: beam spacing, thick slab, deflection

thick slab, deflection, beams: Hi Gohar, The beam spacing is determined mainly by the ability of the slab to span between without excessive deflection and stress. So, it basically depends on the depth of the slab. Normally beams are spaced at a maximum of slab depth x 25 to 30; so for...

Civil Engineering: column design, column design, rebar

column design, rebar, formulae: Hi Yasir, You need to work out the loading on the column floor-by-floor and then use the formulae in the code (such as BS 8110) to design the rebar. Or, instead of useing formulae, you can use spreadsheets from website below: http://www.civl.port.ac.uk/rcc2000/...

Civil Engineering: Eccentric footing Design, footing design, pad footing

footing design, pad footing, tie beam: Hi Girish, I cannot send you an image, but the following will help you. This is a common problem for say a boundary column and you need to design it as an eccentrically loaded pad footing, which will have high pressure at one and (near boundary) and...

Civil Engineering: ETABS Staged Construction, necessary guidance, load case

necessary guidance, load case, construction sequence: Hi Jackie, Sorry for the late response. The following website should give you the necessary guidance: http://csi.structuralwiki.org/wiki_en/images/2/29/Staged_construction_in_buildings.pdf I presume that you gave a load case number for each story...

Civil Engineering: Etabs querries, ETABS IP-max & IP-min

ETABS IP-max & IP-min: Hi Socket, That depends on which code you use, but in any case you should proceed with the design and check that the rebar percentages and concrete/rebar stresses are within allowable limits. Alos read the Shear Wall Design UBC technical manual, E-TN-SWD-UBC97-006,...

Civil Engineering: Final year project topics in Structural analysis and Design(Both by using Steel and Concrete), Final Year Projects

Final Year Projects: Hi Praveen, I (and fellow experts) have answered this question many times before- please browse my past answers using the keywords: Final year project, Projects, Topics Also, the following could be some topics: 1. High strength concrete 2. Durability...

Civil Engineering: Foundations, Boundary edge foundation

Boundary edge foundation: Hi Waseem, This question is a bit too long and complex to help you in detail, but form my experience an eccentric footing with a strap beam should work best- you can also place the footing a bit deeper and take advantage of the weight of the soil and ground-floor...

Civil Engineering: Hollow pot construction, plumbing pipes, reinforcement bars

Civil Engineering: Hollow pot construction, plumbing pipes, reinforcement bars, precast units

Civil Engineering: Slender column design, slab, steel frame

Civil Engineering: Slender column design, slab, steel frame

Civil Engineering: volume - formula for trapezoidal footing, bottom area, trapezoidal footing

Civil Engineering: volume - formula for trapezoidal footing, bottom area, trapezoidal footing, sq rt

Civil Engineering: Hollow pot construction, Hollow-Pot Slabs

Hollow-Pot Slabs: Hi Ibrahim, Hollow-pot slabs are essentially one-way spanning ribbed slabs, but the gaps between the ribs are filled in so as to have a flush flat soffit for plastering. One way ribbed slabs are well covered in BS 8110, and essentially each rib is designed...

Civil Engineering: hello, movement joints, rust treatment

movement joints, rust treatment, floor tiles: Hi Itm, These could be for various reasons, some of which could be: 1. Due to over-loading or rebar corossion- solution: reduce load, remove concrete cover, apply anti-rust treatment and re-apply cover. 2. Cracking of floor, or lack of movement joints....

Civil Engineering: mat foundation, Mat Foundation

Mat Foundation: Hi Saeed, This is quite complex, depending on soil conditions and how the loading is applied. However a mat/raft foundation is suitable for strata with low bearing capacity and/or where differential settlement cannot be tolerated. A raft foundation is...

Civil Engineering: Pad or Piles Foundations, Pad or Piles?

Pad or Piles?: Hi Saeed, I am not quite sure I have understood your question, but the decision as to whether to use shallow footing as opposed to piles is mainly to do with the quality of the strata/ground near the surface. If it is weak or loosly compacted, then you...

Civil Engineering: project, high strength concrete, concrete beams

high strength concrete, concrete beams, flat slabs: Hi Abdul, You have not stated what subject you are interested in, but if it s structures, you could try: 1. High strength concrete 2. Durability of concrete. 3. Optimisation of structures. 4. Punching shear in flat slabs. 5. Long term deflection...

Civil Engineering: RCC Column design, Slender Column design

Slender Column design: Hi Andawei, I am not familiar with BS 1880, but there are charts in BS 8110 Part 3, which you can use in conjunction with the formulae in Parts 1 and 2 to determine additional moments due to slenderness. You can also use spreadsheets as available at...

Civil Engineering: Reinforced column and pad foundation, Safe Bearing Pressure and loads for pad foundations

Safe Bearing Pressure and loads for pad foundations: Hi Bafana, You can get the safe bearing pressure either from local codes or technical literature (depends on location, type of soild, amount of compaction, etc), or you can get some ground investigations done in order to get this info. The imposed loading...

Civil Engineering: Reinforcing Bars Sizes, diameter bar, storage problems

diameter bar, storage problems, reinforcing bars: Hi Jawad, Even in BS, there are only sizes of 6, 8, 10, 12, 16, 20, 25, 32 and 40mm. This is because you can use a combination of different sizes to achieve the result you are looking for. If you had all the different sizes, the manufacturing and storage...

Civil Engineering: rebars, circular section, rebars

circular section, rebars, rebar: Hi Gohar, Actually you can use any cross-section shape, but it just so happens that methods of manufacture make the circular section easier. In the past we used to have what was called square-twisted HT rebar, which was almost square (with champhered corners),...

Civil Engineering: Safe working load for steel wire, high tensile steel, diameter wire

high tensile steel, diameter wire, wire rope: Hi Eddie, The length of wire makes no difference to tensile capacity but does effect the overall elongation due to strain. The ultimate capacity of the 0.08 mm wire (mild steel) would be: 0.005024 x 240 = 1.206 N 1 kg is equivalent to approx 9.8N,...

Civil Engineering: Slender column design, column design, carful

column design, carful, design details: Hi Masoodi, For a column that tall, you will need to be carful about slenderness and buckling (unless the load is very low or you can brace the column at half-height). I cannot do the actual design for you over this forum, but the design procedure is as...

Civil Engineering: tie runner in steel truss, kind perusal, steel trusses

kind perusal, steel trusses, steel truss: Hi Ravi, I am sorry but the drawing is too small to see and this is not a terminology I have come across. If they are ties at the bottom nodes, between adjacent trusses, then they are usually there to brace the bottom chord against buckling when it goes...

Civil Engineering: volume - formula for trapezoidal footing, Trapezoidal Footing Volume

Trapezoidal Footing Volume: Hi Vinoth, Take the lengths of the 2 parallel sides, add and divide by 2. Then mutiply this figure with the perpendicular distance between the parallel sides, which gives you the plan area. Then multipy this last figure with the depth (height) of the base...

Civil Engineering: Water tank, RC Water Tank cover and water-proofing

RC Water Tank cover and water-proofing: Hi Zana, Normally the minimum cover for water tank (without special treatment) would be around 40 mm for the inner surface abd around 25mm for the external surface if it is not subjected to severe exposure. Cover of 5mm is very low indeed and depending...

Civil Engineering: Engineering Interview, ucalgary ca, physics and chemistry

ucalgary ca, physics and chemistry, engineer training: Hi Kayla, I have answered similar questions before, so I will cut/paste them below: ***************************** What skills are required to become a successful civil engineer? What courses did you take in high school in preparation for civil...

Civil Engineering: Benefits of Higher Strenght in wall, strenght, slab

strenght, slab, earthquake: You are right - no point in making the wall too strong if it is not a load bearing member. However, we are talking of higher strength without numbers; some minimum strength is required for the purposes of withstanding other loads - wind, earthquake, etc,...

Civil Engineering: Blinding concrete, Blinding Concrete Joints

Blinding Concrete Joints: Hi Ajay, Normal practice is to not have any joints in blinding concrete, especially if it is cast in reasonable sized lengths/breadths. As it is un-reinfored, it may crack a bit, but that has no structural significance. The only time that joints may...

Civil Engineering: Boundary element length in Etabs, Boundary Elements in RC Wall

Boundary Elements in RC Wall: Hi Shekhar, In this case ensure that you have sufficient rebar to cater for all vertical stress throughout the wall, and then just treat the outer edges as boundary elements (with extra vertical rebar and extra closely-spaced links; the width of boundary...

Civil Engineering: Buildings, Concrete Mix Design & Purlins Design

Concrete Mix Design & Purlins Design: Hi Bernard, 1. This website will help you with full details of concrete mix design: http://concrete.union.edu/general.htm The usual grades of concrete are 10, 15 and 20 N/mm2 for mass concrete and 25, 30, 35, 40, etc N/mm2 for structural rinforced...

Civil Engineering: bridges, span bridges, fly ash

span bridges, fly ash, water interaction: Hi, It s always been a dream of civil engineers to make bridges more efficient and smart. Making longer span bridges are one of them. In reality, because of gravity, bridges needs to be supported somewhere, that means it needs columns, but by increasing...

Civil Engineering: Cantiliver Design, cantilevers, formwork

cantilevers, formwork, alternative solution: Hi Juzar, Your designers are right to be concerned, because for that sort of construction, you will probably need cantilevering beams of between 1.4 to 1.6m depth, so that you can support the slab and also 2 more floors. You will also need very large columns...

Civil Engineering: Civil engineering, Project Topics

Project Topics: Hi Johnson, I (and fellow experts) have answered this question many times before- please browse my past answers using the keywords: Final year project, Projects, Topics Also, the following could be some topics: 1. High strength concrete 2. Durability...

Civil Engineering: Column and Beam Modifier, Member modifiers

Member modifiers: Hi Hamood, You are correct- for strength, or ultimate limit state, you should use the results from the uncracked analysis. The cracked analysis is mainly for servicibility checks- such as lateral sway or vertical deflections and also for dynamic analysis...

Civil Engineering: Cracks, Cracks on wall, curing

Cracks on wall, curing, paintable sealant: Cracks on Masjid wall: Without details on the substrate type, pattern of cracks, time of appearance, we cannot identify cause. Assuming wall is built of pre-cast blocks and cement plastered, and considering the climate in ME, following could be most probable....

Civil Engineering: civil engineering, LRFD vs ASD

LRFD vs ASD: Dear Questioner You had three questions that I am going to answer them briefly. 1) Limit state design(LSD) or LRFD is preferred over working stress design or allowable stress design(ASD) … read more at : http://www.bgstructuralengineering.com/BGASCE7/BGASCE7002/BGASCE700203.htm...

Civil Engineering: Deflection Rate, Overall Movement Joint Gap or width

Overall Movement Joint Gap or width: Hi Daven, I am not quite sure what you mean by deflection rate, but the joint gap should be enough to cater for lateral expansions of both buildings and also for lateral sways due to wind and earthquake, taking ductility into account for the latter, so...

Civil Engineering: Dynamic Analysis, Dynamic Analysis

Dynamic Analysis: Hi Hamood, You only need to use dynamic analysis for buildings that are dynamically sensitive- such as ones with very long spans or ones that are very slender (say height/width ratio more than about 4) or ones that do not have a uniform and symmetrical...

Civil Engineering: Eccentric footing Design, footing design, pad footing

footing design, pad footing, tie beam: Hi Pal, I have answered this before, if you had browsed my previous Q&A: ********************** Question: Can i have image %26 calculation sheet with example for eccentric footings. I want complete calculation of eccentric footing step by step also...

Civil Engineering: Engineering, consistent load vector

consistent load vector: Please, read this page: http://books.google.com/books?id=UAY50SPjDRUC&pg=PA128&lpg=PA128&dq=%22consistent+load+vector%22&source=bl&ots=KDc38y7bzH&sig=3G1FpsVj8hIlY6s0j9lZU5nX_HQ&hl=en&ei=2EkoTbTkKcGKswbEg_jbAg&sa=X&oi=book_result&ct=result&resnum=5&ved=0CC8Q6AEwBA#v=onepage&q=%22consistent%20load%20vector%22&f=fals...

Civil Engineering: Thesis Topic about materials, high strength concrete, concrete technology

Civil Engineering: Thesis Topic about materials, high strength concrete, concrete technology, polymer

Civil Engineering: Geotechnics, Dam Foundation Seepage

Dam Foundation Seepage : Hi Monsur, This is not really my area of expertise, but I would imagine that an RC wall cut-off barrier, extending some metres below the foundation, together with a grout curtain, will certainly reduce your potential seepage problems. Refer also to this...

Civil Engineering: irrigation system, Culverts

Culverts: Hi Esther, They are designed differently, as circular one mainly work by radial compression whilst ractangular ones work by bending/shear. The rectangular ones have more capacity per unit height and use less fill above if crossed by a road. The circular...

Civil Engineering: mat foundation, Raft Foundation Design

Raft Foundation Design: Hi Rekha, You can model the matt/raft sitting on springs (stiffness determined from ground investigations) at regular intervals and then do a 3-D FEA analysis using STAAD or SAFE or ANSYS, etc. Then you will need to do an upper-bound and lower-bound analysis,...

Civil Engineering: About Reinforcing Steel, passivating layer, tensile properties

passivating layer, tensile properties: A very interesting question! There are 2-3 key reasons why we use only steel as the reinforcing material. 1. Thermal co-efficient of expansion: This for steel is closest to that of concrete. 2. Corrosion resistance: All metals corrode; the first layer of...

Civil Engineering: r.c.c. design & tho., RC Design Books

RC Design Books: Hi Kailash, Please note that this forum is in English. Try these 3 books: 1. RC Design to BS 8110 Simply Explained, by A.H. Allen 2. RC Designer s Handbook, by Charles E Reynolds and James C Steedman 3. Designed and Detailed by J B Higgins and...

Civil Engineering: Science Fair, Interview Q&A

Interview Q&A: Hi Miguel, If you browse my past answers you will find I have a detailed Q&A session for an interview. To answer your questions: 1. I had an interest in Physics and model-making and art- so all these combined are good for structural engineering. 2....

Civil Engineering: structural design for duplex house, duplex house, steel specifications

duplex house, steel specifications, structural calculations: Hi Suneel, I am happy to hear that you read my past answers before asking more. The information you have provided is not sufficient to give a definitive answer, but from experience I would agree with you that certainly the rebar in the beams should be...

Civil Engineering: Tanks design, Joints in Water Tanks

Joints in Water Tanks: Hi Ahmed, If you had checked my past answers, you would have found the following: ******************* Question: Dear Mr Arshad What is the criteria of providing expansion joints in large water tanks. Answer: This depends on whether the tank...

Civil Engineering: Temperature forces in Staad, Temperature Loading in STAAD

Temperature Loading in STAAD: Hi Sachin, Basically you need to decide on the temperature range between night and day (and also between winter & summer), and then apply the difference (say 45 to 25 = 20 degrees C, which could be plus or minus sign) to the long members (normally to beams...

Civil Engineering: Thesis Topic about materials, Construction Materials Topics

Construction Materials Topics: Hi Ryan, Some topics I have listed previously are: 1. High strength concrete 2. Durability of concrete. 3. Optimisation of structures. 4. Punching shear in flat slabs. 5. Long term deflection of concrete beams/slabs. 6. Modern methods of construction....

Civil Engineering: using load cases in footing design ..., wall footing, footing design

wall footing, footing design, soil pressure: Hi Wayne, I am not too familiar with IBC, but on first principles you should design the RC structure for the worst loading, which could be an envelope of wind and ultimate gravity loading. If the worst case includes wind, and if that moment is much higher...

Civil Engineering: cable-stayed bridge, axial force, bending

axial force, bending: Dear Mohammad Salam It is recommended in structural engineering to shift strength mechanism of structures from bending to axial. It is more efficient and economical and easy to do. Trusses are alternatives of plate girders in long spans. When you cant...

Civil Engineering: how to calculate vertical load on a wall, Wall loading

Wall loading: Hi Eric, Just work out the tributary areas of all slabs spanning on to the wall and multiply by (self wt. + live load) and do the same for any point loads, such as beams resting on the wall, and also add the self weight of the wall. Then if you have more...

Civil Engineering: civil, asphalt, density

asphalt, density: Dear Nadeem The general Formula of deriving weight from volume is a physic problem , you must know it. The essential problem for you is to have a density in hand.it can be from 1.8 to 2.4 but 2 is the most expected value for density of asphalt. Regards...

Civil Engineering: Civil Engineering work from home, work from home

work from home: Dear Patel Great idea, but in our country no such a topic is available in civil eng field. You must look for it in your own country because engineering topics may need a minimum of physical touch and presence in work area. But I will let you know in the...

Civil Engineering: Class 30 Cement content, Aggregate grading concrete mix

Aggregate grading concrete mix: Hi Vishal, I am not sure what 32.5 ppc is, but you are using far too much cement for 1m3 of concrete! When I said that aggregate grading is important, I did not mean maximum or nominal size of aggregate- it is what proportion the aggregate has of 19mm,...

Civil Engineering: Conduit in concrete, conduite, concrete

conduite, concrete, reinforced: Dear Arif Naturally never a code will allow to weaken the basis of theoretical assumptions. But you must design so that you can justify and defend your design. I suggest you to follow a combination of these suggestions 1- Let the conduits run in lower...

Civil Engineering: conduits in concrete, conduits effects on section design

conduits effects on section design: Hi Arif, This depends on the location and orientation of the conduits in relation to principle axes for shear and bending. I am assuming that axial load/stress is not an issue due to the large thickness of the wall. For shear, you just reduce the area...

Civil Engineering: Deisgn of Ramps in ETABS, etabs, ramp

etabs, ramp: Dear Kamran Salam You must take care of your ramp not to be defined as rigid plate. Rigid diafragm will join upper and lower levels together and then no differential displacement and then no internal forces and stresses between them will be allowed ....

Civil Engineering: design of strip footing with columns not wall, pad footings, strip footing

pad footings, strip footing, zaky: Hi Zaky, First of all, the question would be why have a strip footing for columns? The reason I ask is that if the columns are say 6m spacing, then the strip footing around 1m away from the columns will be ineffective, unless it is very deep/stiff. Normally,...

Civil Engineering: ductility & stiffness, buling, wind loading

buling, wind loading, lateral loads: Hi Ravi, 1. Stiffness determines how much a structure will deflect for a given load. Ductility determines how much the structure can deflect without failing/collapsing, and how much energy can be dissipated by that deflection/deformation. 2. This depends...

Civil Engineering: foundation design, Punching, foundation

Punching, foundation: Dear Alexander Salut You may know that the design processes which are in hand and we apply them to size our systems and structures are established based on 2 main criteria: 1- Theoretical basis 2- Experience basis ( Laboratory and actual application)...

Civil Engineering: foundation engineering, footing

footing: Dear Pika Your question is not so clear but for a preliminary help I can say: 1- The reinforcement arrangement depends on the degree of rectangularity of your footing. If you had a square footing you would use same reinforcement in both direction. For...

Civil Engineering: Impact Noise near Bridge Expansion Joints, Bridge, design

Bridge, design, neoprene: Dear Ruwan Something very important in bridge design is related to design of supports which are located in vicinity or same location with expansion joints. Supports are equipped very frequently with Neoprene which is a polymer or rubber ( Natural or synthetic)...

Civil Engineering: Joints in concrete structures, construction joints, differential settlement

construction joints, differential settlement, temperature variations: Hi Arif, Joints in concrete are required for two main reasons- to prevent early-age cracking of the concrete and to limit temperature stresses due to expansion/contraction. Another possible reason could be to permit differential settlement (e.g between...

Civil Engineering: Moment redistribution, continuous beams, gravity load

continuous beams, gravity load, gravity loads: Hi Abdurrazak, As I explained earlier, moment redistribution can only be done for continuous beams (not simply supported beams). So, if you reduce the hogging moment at the supports, it increases the sagging moment at the midspan (to a maximum of w*l*l/8,...

Civil Engineering: Planning, Labor, Project

Labor, Project, Machinery: Dear Colleague Siddic The weight of activity must be calculated on a real physical basis to show the real progress of the activity during the construction. For this purpose we have to pull out the cost of materials from the total cost. Then it remains a...

Civil Engineering: RC DESIGN (hollow section), neutral axis, compressive stress

neutral axis, compressive stress, section modulus: Hi Abdurrazak, If the section is symmetrical (such as a circular tube), then the neutral axis will be right through the centre and the compression/tension stresses due to bending will be equal on opposite sides of the section, assuming the wall thickness...

Civil Engineering: settlement of soil, soil particles

soil particles: Hi Sushma, This ocurrs when the air voids within the soil particles get compressed so that the overall volume of the soil becomes less and hence the soil top level settles down- usually occurs when you apply a load from the top- such as from a foundation...

Civil Engineering: Shear checking at footings, spread footing, shear

spread footing, shear: Dear Sirisha The punching shear failure mode is more likely to happen in very soft soils. The wide beam shear (one way as you said) failure mode may happen in hard soil sites due to lower foundation size. Then I warn you to check both shear modes in...

Civil Engineering: strengthening of column, Repair, Rc Column

Repair, Rc Column, Jacketing: Dear Raviarjun I must know more about your problem, to decide about the thickness of plates. This is a design problem. Bust as a rule of thumb no less than 8 mm thickness could considered as effective. To constrain the jacketing and existing column to...

Civil Engineering: strengthening of footings, epoxy grout, rebars

epoxy grout, rebars, purlins: Hi Ravi, You can excavate around the existing base, expose the rebar to sufficient depth (from the sides) to enable new rebars to be welded to old ones in both directions, so as to increase the width and or length of the base. If the original rebar is not...

Civil Engineering: Tank base slab on ground, finite element analysis, rigid conditions

finite element analysis, rigid conditions, tank walls: Hi Boni, For rigid conditions (asumming stiff/rocky ground), the base slab is designed with nominal rebar, just to prevent shrinkage cracking, plus additional rebar along the edges to cater for moments/shear from the tank walls. For flexible ground conditions,...

Civil Engineering: Tensegrity structure, tensegrity, structure

tensegrity, structure, truss: Dear Akmal Salam Tensegrity is not a very new structural concept but may be a modern architectural approach. It consists of making a tension compression mechanism instead of bending and shear in structure. Trusses are the most known structures with...

Civil Engineering: Thermal analysis, horizontal displacements, aci 318

horizontal displacements, aci 318, daily variation: Hi Kamran, That is a very high gradient- surely the daily variation will not be more than 10 to 15 degrees? In any case, what you can do is provide temporary thermal/pour strips around the shear walls (where you cast the concrete after sometime when the...

Civil Engineering: thermal pour strips, shear walls, splices

shear walls, splices, formwork: Hi Kamran, The pour strips should be no wider than 1 to 1.5m, so that the rebar lap splices happen within that zone. So for beams, it would be best to locate the strips within a zone 1/4 span to 1/2 span from the supports where shear is low. If you keep...

Civil Engineering: Ties for column, Column, ties

Column, ties, overlap: Dear Arif As you suggested yourself , the straight development length is the key of such a problems. If you need more assistance you can email me your column details ( babak.e.hakimi@gmail.com) then I can have my exact suggestion. Regards Babak Esmailzadeh...

Civil Engineering: Water Cement Ratio, concrete mix design, cement ratio

concrete mix design, cement ratio, exact formula: Hi Shahzad, This depends on a lot of variables, but this website gives you the procedure: http://www.civilcraftstructures.com/materials-testing/steps-of-concrete-mix-design/ Also, browse my past answers with key words water cement ratio and...

Civil Engineering: Base slab, water tank, foundation

water tank, foundation, rigidity: Dear Barek Hello, in the case of cylindrical water tank, usually a ring basement under water tank shell will provide what you need as stiffness on ground level connection. The base slab bears only the weight of water on a uniform strength soil. The soil...

Civil Engineering: best options for 24m long span beams, 24m span beams options

24m span beams options: Hi Venkat, Technically, I would say that only options 1, 2 and 3 should be considered- there is not much benefit in using box girder and there are complications in design and construction. Another option you can consider is to cast the concrete beam...

Civil Engineering: civil engineering, geologist

geologist: Dear Waleed It is up to you , but generally a graduated geologist can follow his/her dreams either in soil mechanics and foundation engineering or earthquake engineering. You can be then a civil engineer as you might like. I know someone who was graduated...

Civil Engineering: design of concrete structures, Weight building

Weight building: Hi Ankit, Fot calculating overall building loads/weight, you need to assess the self (dead) weight of the structure by calculating the volume of concrete/finishes/internal walling, fascades, etc, and multiplying with the densities or weights from catalogues,...

Civil Engineering: Eccentric Footing-2, Footing, eccentrencity

Footing, eccentrencity: Dear Sirisha I didn t mind to put tensile reinforcement. I meant when moment intensity (eccentricity) increases on a footing the footing tends to over turn. By increasing the intensity of moment from zero up you can see in your calculations that the stress...

Civil Engineering: Eccentric footing-2, eccentricity, footing

eccentricity, footing, 5m: Hi Sirisha, Based on the info provided, even if there was no eccentricity, the UDL pressure works out at 370 kN/m2 which is already higher than the SBC. Therefore the base needs to be increased in size, especially towards the left side- so make it a trapazoidal...

Civil Engineering: Eccentric Footing, footing, eccentric

footing, eccentric, moment: Dear Sirisha Your calculations are correct. You can either increase the allowable stress of soil by strengthening it in an area and depth which has to be designed and sized carefully, or increasing the dimensions of your footing or even to use a strap footing...

Civil Engineering: Eccentric Footing Design, footing design, eccentric moment

footing design, eccentric moment, sirisha: Hi Sirisha, I am sorry but the text is not readable, but I note that your pressure sketch under the footing pad seems to be incorrect, as you should have higher pressure under the column. If the pressure is only 10-15% higher than SBC, then you can accept...

Civil Engineering: footing, footing, pile

footing, pile, piling: Dear Ayman Please send me your problem so that i can suggest you a solution. In the case of uplift not balanced with vertical loads you will need to provide heavier footing or applying vertical Friction or Mass based piles. In the UK both solutions are...

Civil Engineering: foundation design, punching

punching: Dear Alexander You must do check the punching effect by assuming total vertical load submitted by column being resisted by lateral area of a cut prism around the column base in foundation. Please take a look at BOWLES. Regards Babak E Hakim...

Civil Engineering: FOUNDATION DESIGN, design, footing

design, footing: dear alexandra I have designed a program to give you instructions about spread footings design. I start my program today with a short lesson about load combination: 1st step : load combination Design process includes 2 main steps 1- Soil stress...

Civil Engineering: foundation design, church, bid

church, bid, foundation: Dear Alexander You must arrange to put the most critical moment reinforcement ( say the longest side rods) in lower level considering the appropriate cover. you must replace the other direction rods directly on the lower rods. I sent you a pic but I haven...

Civil Engineering: how to interpret reinforcement, ETABS shear wall rebar

ETABS shear wall rebar: Hi Eric, If you look at the output tables, it will tell you how much rebar is needed (mm2/m), which is equally split between the 2 faces of the wall. Alternatively it will tell you the length of the boundary member and the total rebar within the boundary...

Civil Engineering: Need Help regarding steel type, corrosion, galvanizing

corrosion, galvanizing, steel: Dear Baljeet Singh All these conveniences together will be expensive in price for you. To be reasonable you can try to replace welded connections with pinned or bolted connections. Another method to protect your steel deck of trucks against corrosion...

Civil Engineering: pad foundation design, Foundation

Foundation: Dear Alexander Take a look at the link : http://www.fortunecity.co.uk/campus/art/391/padfound.html I don t have any idea about Gcol , Gsoil and Gpad I hope you would be successful. After all don t hesitate to ask me further. Regards Babak E....

Civil Engineering: Raft Foundation, compression, reinforcement

compression, reinforcement: Dear Mahmud Salam Aleikom When you lay a mat or raft foundation on the soil , soft soil for example , you will have tendency to crack in areas between columns ( lower part) and in areas near and under columns ( upper part. Then you will need usually...

Civil Engineering: RCC Beam, USD, ASD

USD, ASD, Strength: Dear Sirisha You must notice a couple of matters: 1- Your loading combination must be defined as USD ( Ultimate Stress Design) or ASD ( Allowable Stress Design) . Nowadays ASD is expired but you can still use it. Please have a study on USD design and...

Civil Engineering: Slab Design, slab

slab: Dear Nirojan This is a problem of analysis of slabs under arbitrary loading. 1- First step is to using a software or by plastic hinge concept or any desired method. 2- Then you will have to combine internal moment and shear due to dead load and live...

Civil Engineering: Steel section size, steel beam bending moment shear

steel beam bending moment shear: Hi Mulugheta, You have not given me enough information to give you a precise answer, as I need to know the section properties of the beam. Basically, if the load is uniformly distributed, then the maximum bending momnent will be (750x 5.8^2)/8 = 3154...

Civil Engineering: Stiffness modifiers(modification factors)for etabs, etabs, Stiffness

etabs, Stiffness: Dear raviarjun you must use several files to be able to compare the effect of stiffness modification. You cant make a comparison using a single file because each file and each solution is based on a single Stiffness Matrix To model your modification change...

Civil Engineering: Structural RCC columns, joggling, RCC

joggling, RCC, concrete: Dear Damodhar Any forced and persistent displacement leading the structure in plastic behavior area, must be regarded as prohibited unless you can justify the situation as non hazardous status with due mechanical and structural analysis. As a rule of thumb...

Civil Engineering: alignment of RCC columns - lapping, Concrete admixture

Concrete admixture: Dear Ramamurthy Concrete admixture is very serious even for moderate range of strength. Pit sand cant replace sand in concrete and sand cant replace gravel. I suggest this formula to be tested ( this is not very accurate but a guide) : 600-800 kg...

Civil Engineering: analysis part, concrete finishes, high rise building

concrete finishes, high rise building, applicable standards: Hi, You start by working out the loads, as per my earlier Q & A: Question: Sir,I have to submit a minor project on design of high rise building .how the dead load is estimated for design of building structural parts ? according to Indian standard code...

Civil Engineering: Bar bend diameter problem, rebar bend radius

rebar bend radius: Hi Waseem, This has two possible implications: 1. The bar could have developed cracks or strain hardening along the sharp bend, hence weakening the rebar. 2. If the bend in the bar is there to provide anchorage and the stress in the bar is high, you...

Civil Engineering: baseplate area expansion, base plate, weld

base plate, weld: Dear Raviarjun I need to have your details along with your loading details , to better give my idea, but as a general rule no matter to weld 12 mm thickness to a 6 mm one. You shall use a normal square weld along the interface of 2 plates. It is strange...

Civil Engineering: buiding construction, Loading, load combination

Loading, load combination: Dear Durga Loading on buildings is a very wide feature which must regarded through a systematic approach. For start I suggest you to take a look on a national code of practice , like Indian code of practice or UBC. You have several types of loading...

Civil Engineering: Cement cracks., creep, cement

creep, cement, concrete: Dear Suraj As a general rule all cracks are due to strain and deformation, in cement and concrete creep due to water evaporations in short time and general long time creep are the main sources of cracks. To avoid from cracks you can apply light steel or...

Civil Engineering: Characteristic strength concrete (fcu), prestressed concrete

prestressed concrete: Dear Henry No serious limit exists for concrete strength, but you must have reliable source to provide you with qualified and reliable concrete. But, but , but be careful about prestressing rods. They must be qualified to be applied in prestressed members....

Civil Engineering: Corrosion protection, corrosion protection, rebar

corrosion protection, rebar, google: Hi Suraj, There are many ways this can be done, such as cathodic protection, painting, galvanising, etc, etc. I suggest you Google this topic to get more details. For rebar, by embedding it in good quality dense concrete, with adequate cover, also results...

Civil Engineering: Design of beam using SAFE, safe, beam

safe, beam, girder: Dear Meda It is preferred not to use safe as a beam design tool. You can use Etabs to design girders and beams. If you import Etabs file into safe you will be able to consider deflection of beams as marginal conditions of slabs, to optimize the slab design....

Civil Engineering: Design of Earthquake building, mode of vibration

mode of vibration: Dear Summaya Noor 1- I give you an example. Have you ever analyzed a number like 72 into its primer components? like this: 72= 2^3 * 3^2 Then you can say that 72 has 2 component : 2 and 3 you can say that 72 has 2 modes : 2 and 3 you can...

Civil Engineering: design of seismic building, Seismic comparison base isolation

Seismic comparison base isolation: Hi Fiza, Strictly speaking, you should do dynamic amalysis for both options, but if you are running out of time you could justify not doing this because what you are doing is a COMPARISION. So long as the static analysis parameters are the same for both...

Civil Engineering: Eccentric footing, vertical load, rashmi

vertical load, rashmi, footing: Hi Rashmi, In that case you have what is called an eccentric footing , so that the net pressure below the footing will not be uniform due to the moment caused by the vertical load times the amount of eccentricity. If you need more info, please browse...

Civil Engineering: EMBDEDED CONNECTIOND DETAILS, steel embeded column

steel embeded column: Hi Waseem, I presume the W33 is a typo? I do not know of any references, but I would embedd the steel column for a depth of at least 1.5 to 2m, with lots of studs along all sides to transfer the axial load by shear/dowel action. You should also add additional...

Civil Engineering: End of the world., life, sorrow

life, sorrow: Dear SurajLaghe You know what? Human is a model maker. Human is a resolver. Human models every thing in the world and resolves it. What is his/her pattern to make a good model? Human ghost, human spirit. We make models with an eye on ourselves. The earth...

Civil Engineering: Final Year Project, reasearch topics

reasearch topics: Dear Shilpa You have a lot of opportunities. You can look for in Internet. The main topics are: Earthquake Engineering, Active and Passive control, Base Isolation, Dampers, Special types of bracings, Friction based bracings, high strength concrete, fiber...

Civil Engineering: Flat slab detailing & punching shear, flat slab rebar detailing punching shear

flat slab rebar detailing punching shear: Hi Meda, 1. Yes, this is acceptable, so long as you ensure proper lap between mesh and additional rebar. You can get some further details from this website: www.rds.com.vn/uploads/Flat_Slab_Design.pdf 2. No, you need to take the column reaction and...

Civil Engineering: Horse shoe tunnel area calculate, tunnel area, shoe type

tunnel area, shoe type, horse shoe: Hi Sanjay, If you had browsed my past answers you would have found this: QUOTE The best way to do this is to divide up the X-section shape into a semi-circle, a rectangle and possibly 2 triangles at the sides (if the sides are not vertical). Then...

Civil Engineering: 'Lime' is use as building material, lime

lime: Dear Suraj Laghe The broadly used term lime connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminum, and iron predominate, such as limestone. By contrast, quicklime specifically...

Civil Engineering: Load transfer to beams, prestressed concrete structures, zbaby

prestressed concrete structures, zbaby, self weight: Hi Naveen, You work out the self weight of any slabs and beams spanning on to the beams, and the imposed loads and then calculate how much of these are being supported by the beam- it depends on whether the slabs are one-way spanning (in which case the...

Civil Engineering: how to model truncated dome by finite element method, Dome generation in ETABS

Dome generation in ETABS: Hi Helina, If you had browsed my past answers you would have found this, and the earlier description of how to do it in ETABS. Then to truncate it, just draw a line or element at the appropriate locations and where these intersect you can split and delete:...

Civil Engineering: Newton's 1st laws of motion, Newton Laws

Newton Laws: Dear SurajLaghe The Newton laws are conditional. IF the resultants of forces acting on a body remain strictly zero, no acceleration will happen and the velocity will remain constant. When friction acts on a body a brake force acts on the body forcing it...

Civil Engineering: about shear, shear force stress

shear force stress: Hi Isuru, For any gravity loading on a beam, the shear is the vertical reaction at the support, or varying vertical force within the member, due to externally applied loading. For example, if a beam is 10m span and weights 2 kN/m and you apply a UDL loading...

Civil Engineering: UDL v point load on a slab, Point load grade slabs

Point load grade slabs: Hi Geoff, Sorry, I had assumed that the slabs were suspended/upper storey. For ground-bearing slabs, the principles are different, as the capacity depends mainly on the quality of the sub-grade and how much compaction it was subjected to. Grade slabs are...

Civil Engineering: WIND LOAD DRIFTS, earthquake design criteria, statistical probability

earthquake design criteria, statistical probability, partition walls: Hi Waseem, This is the usual statistical probability used in most codes- for example the acceptance of 28 days cube strength is also based on the probability that only 5% of the results would fall below the specified strength. So, it is the same with...

Civil Engineering: Wind Loading on Lattice Structure, lattice structure, negative suction

lattice structure, negative suction, wind loading: Hi Syed, Wind loading on a lattice structure is complicated due to local turbulance, vortices, suction, etc caused at the downwind side of the steel members, so sometimes it is simpler to assume conservativel that one face of the tower is subjected to the...

Civil Engineering: bricks and hollow blocks, clay brick pavers, concrete masonry association

clay brick pavers, concrete masonry association, national concrete masonry association: Dear Kevin, Since you need answers to help you on with your research papers, I would recommend the following to start with; others can be found through the references found under many of these: 1. BDA Design Notes 7 on Brick Durability, Aug 2006 2. Design...

Civil Engineering: Column Model in Etabs, column model, sajeev

column model, sajeev, cardinal point: Hi Sajeev, In this case you are telling me that the column is 2 ft or more wide? The two ways you can model this is to either model the beam at the centre line and then apply a torsional moment equal to the shear times eccentricity, or else have a stiffer/transformed...

Civil Engineering: Design of a circular slab, slab design, scribd

slab design, scribd, rebar: Hi Ronald, Yes, circular slabs analysis and design is different from rectangular slabs, as the deflection and resulting strains and stresses are radial and circumferencial, as opposed to orthogonal as in rectangular slabs. The rebar also needs to be detailed...

Civil Engineering: Design of RC Circular Hollow Mast, muscat oman, section modulus

muscat oman, section modulus, shear stresses: Hi Sudhakar, Good to hear from you! You can model this in STAAD or SAP2000 (or similar), or do what we used to do in the old-days, which is work out the section modulus and then as it is a cantilever, the moments and shears are easy to analyse at different...

Civil Engineering: design examples, arrangment, web sources

arrangment, web sources, google: Hi Sachin, There are a lot of web sources, which you will find by putting appropriate keywords in www.google.com Two such examples are: http://books.google.com/books?id=o_mKzwhbeHkC&pg=PA307&lpg=PA307&dq=rc+roof+slab... http://www.civilengcalculations.com/index.html...

Civil Engineering: ETABS pin - support, lateral loading, shear walls

lateral loading, shear walls, footing: Hi Hamood, This is probably becuase you have some shear walls? In that case, the coupled forces at the corners of the walls will generate a moment. Try a model with just columns, all pinned at the bottom, and there will be no moments. However, also...

Civil Engineering: ETABS vertical load on shear wall, shell area, ground tank

shell area, ground tank, vertical load: Hi Rahman, 1. Yes, if you want to apply a point load. make sure it is at a node (i.e. mesh the wall so, that there is a node/joint under the point load. If you want to apply a line load, then model a dummy beam (say same width as wall, and with depth equal...

Civil Engineering: Etabs modeling of soil pressure, soil pressure, horizontal strips

soil pressure, horizontal strips, horizontal direction: Hi Sajeev, In ETABS, all beams at different levels need to be on their own Story , so just create an intermediate dummy story 2 feet below the main and draw your beam there- also the column will have a node at that level. ETABS is mainly for buildings,...

Civil Engineering: expansion joint, Seismic Gap for 2 adjacent buildings

Seismic Gap for 2 adjacent buildings: Hi Niral, The width does need to increase with height, but only if it is a seismic zone. Basically you need to analyse both buildings, work out the inelastic drifts/overall sways for both, then add them as per the formula in UBC 97 to come up with an overall...

Civil Engineering: Foundation /Geotechnics, Vibrocompaction & raft foundation

Vibrocompaction & raft foundation: Hi Amani, 1. I am not an expert on vibroflotation or vibrocompaction, but the following website will guide you: http://www.vibroflotation.com/ 2. Yes, in principle if you vibrocompact the soil properly, possibly in conjunction with using stone columns...

Civil Engineering: Foundation type, raft foundation, building a raft

raft foundation, building a raft, differential settlement: In that case a raft foundation is best as it minimises overall applied pressures and also reduces differential settlement between one part of the building and the rest- if you have isolated footings, one could settle more than the other and this causes cracking...

Civil Engineering: Etabs modeling of soil pressure, mumtaz

Civil Engineering: Etabs modeling of soil pressure, mumtaz

Civil Engineering: Load bearing strength of steel tube filled with compressed water, lateral loading, axial compression

lateral loading, axial compression, lateral load: Hi David, That s an interesting concept, which I have not come across before. Looking at it from first principles, as water is more compressible than steel, I do not think there will be any direct enhancement of vertical load capacity, apart from perhaps...

Civil Engineering: Pillar type home or conventional foundation type home-which is good?, soil characteristics, structural engineer

soil characteristics, structural engineer, conventional type: Dear Mr Mallappan, For a home both types are normally suitable; conventional is usually more economical. Economy also depends on how tall your home will be, the soil characteristics and the water table at the site. If high water table, clayey soil, an...

Civil Engineering: Portal frames, portal frames, fire proofing

portal frames, fire proofing, question index: Hi Rajit, You have not mentioned whether this is in RCC or steel. Both will have similar analysis methods, but the detailing and connection and fire-proofing will be different. Portals can be either without any joints, or with hinges (pin supports) at the...

Civil Engineering: Squash Court Wall, wire mesh, squash ball

wire mesh, squash ball, dr khan: Hi Murvin, I am not an expert in this particular field, but my judgement is that the loading from a squash ball (NOT tennis ball) will not justify requiring infill concrete, but certainly incorporating a wire mesh (like expnded metal or chicken wire) in...

Civil Engineering: sloping roof without support at centre, horizontal thrust, horizontal beams

horizontal thrust, horizontal beams, roof loading: Hi Sachin, Yes, it is possible, but there will be significant horizontal thrusts at the eaves level (where slope meets the walls), so your walls will need to be strong enough to resist that horizontal thrust. If you can incorporate horizontal beams, which...

Civil Engineering: Wall Plaster Thickness, wall plaster, masonry blocks

wall plaster, masonry blocks, masonry wall: Dear Ashish Morey, Sorry to be responding late, as I was on vacation. My understanding of your question is why wall is considered of better quality if thickness of plaster applied is less . Plastering is done to cover up all surface irregularities and...

Civil Engineering: Building load calculation, RCC Building Weight

RCC Building Weight: Hi Faruq, Fot calculating overall building loads, you need to assess the self (dead) weight of the structure by calculating the volume of concrete/finishes and multiplying with the density, and you need to apply the imposed (live) loads in accordance with...

Civil Engineering: Restaurant Construction, raft foundation, construction question

raft foundation, construction question, marshland: Hi 1234, So, what you meant is ask is whether the marshland would have an effect on the columns? Surely thsi depends on whether you have constructed the columns bases on sound ground or not. If the bases are well below the ground surface, where erosion...

Civil Engineering: Seismic LOad, Dubai Seismic analysis using ETABS

Dubai Seismic analysis using ETABS: Hi Kamal, Using the default UBC (not IBC)loading with zone 2A is fine for Dubai- it is not over conservative. You need to use the correct parameters for the soil conditions and the R factor, depending on the structural system of your building and you should...

Civil Engineering: Stifness modifier, columns design, elastic analysis

columns design, elastic analysis, eng tips: Hi Farooq, For drift limits, you are right about the factors quoted, although even here if the walls are shown to be un-cracked during initial analysis, you do not need to apply the walls factor. There is, however, divided opinion about this subject...

Civil Engineering: structural design, brick wall, expansion joint

brick wall, expansion joint, structural design: Hi Kishore, It is difficult to advise properly without more details, but I suspect that these are temperature movement cracks due to the roof slab expanding and the wall below being cooler, not expanding at the same rate. I suggest that if the slab is structurally...

Civil Engineering: CORE CUTTING IN RCC BEAM, arshad khan, approximate measurements

arshad khan, approximate measurements, diameter hole: Hi, You should try and avoid cutting through sturrups, unless the hole is within the middle third span where shear is low. Also, avoid cutting central rebar, which is there for crack-control, but if it cannot be avoided cutting it should not affect structural...

Civil Engineering: CORE CUTTING IN RCC BEAM, hole dia, shear stress

hole dia, shear stress, shear forces: Hi Vidhushekhar, This depends on the depth of the beam- if the beam is only 10cms deep, then cutting a 3 cm hole may be a problem, but if the beam is more than 15 or 20 cms deep, then a 3 cms hole should be no problem, so long as you place it centrally...

Civil Engineering: civil engg, Setting up a practice in India

Setting up a practice in India: Hi Manzoor, Sorry, I do not know what the regulations are in India- I suggest you consult the local Engineers Institution. Also, I would strongly recommend that you first get 2-3 years experience working for a company, under the guidance of an experienced...

Civil Engineering: computer terms in civil engineering, project planning and scheduling, computer terms

project planning and scheduling, computer terms, structural design: Hi Zain, Basically computers are tools to speed up the processes you list above (before computers were around as PC s, all the above could be done manually, albeit slower). Similarly there are many software packages that also speed up all the above activities,...

Civil Engineering: diaphragm wall, Reduced Bond in Bentonite concrete

Reduced Bond in Bentonite concrete: Hi Tung, Yes, so that is exactly what I said before- the rebar strength is not affected, but the bond strength is reduced, as that depends on the quality of the concrete, not the rebar. So this must be because of the uncertainty of the degree of compaction...

Civil Engineering: Euro code, annex a1, load combinations

annex a1, load combinations, seismic load: Hi Muthu, 1. In this case, unfavourable for overturning would be without dead weight of equipment, and vice versa. Similarly 1.0DL + 1.4WL would be unfavourable and 1.2 (DL+LL+WL) would be favourable. 2. Yes, you can use same factors as WL for DL and...

Civil Engineering: f'c and fcu, Cylinder and Cube Strengths Comparision

Cylinder and Cube Strengths Comparision: Hi Mohamed, If you had first browsed my past answers you would have found the following: Generally a cylinder test strength is between 5% and 25% less than a cube test strength for a given concrete mix, the percentage difference decreasing with an increase...

Civil Engineering: f'c and fcu, character strength, strength of concrete

Civil Engineering: f'c and fcu, character strength, strength of concrete

Civil Engineering: interview, physics and chemistry, engineer training

physics and chemistry, engineer training, civil engineer: Hi Shivam, I have answered these types of questions before, so if you do not mind, I will cut/paste the Q&A for these below: ***************** Q. What skills are required to become a successful civil engineer, and what courses did you take in high school...

Civil Engineering: Modelling of Ramps in ETABS, shell elements, ramp area

shell elements, ramp area, beam element: Hi Jayant, Unless you take care, all loading from slab/ramp elements to supporting beams will only be transferred at the 4 corner nodes. You can either mesh the elements finer (and the supporting beams), or else use special one-way distribution, using membrane...

Civil Engineering: model export from ETABS, ETABS sizing for core walls

ETABS sizing for core walls: Hi Kamran, This really depends on the relative size and location of the liftcore to the rest of the building and whether you plan to resist all lateral loading by the core, or by a dual system with moment resisting frames. For an 11-story building, I...

Civil Engineering: Practical problems., Site Concrete Quality Issues

Site Concrete Quality Issues: Hi Ananta, 1. This depends a lot on the mix, the water/cement ratio and the prevailing temperature. As a rule, the maximum time you should allow is between 30-45 minutes, but always check the slump before pouring. 2. No adjustments should be allowed...

Civil Engineering: pad foundations, allowable bearing pressure, pad foundation

allowable bearing pressure, pad foundation, punching shear: Hi Kaye, This depends on whether there is also bending moment or not, and also on the grade of concrete and the size of the column, so that you can check the punching shear and momnet capacities. Based on the limited info you ahve given me, the pad will...

Civil Engineering: point load on raft footing, Raft Loading

Raft Loading: Hi Ananta, You should only consider the raft as rigid , if the thickness is more than about 0.2 to 0.25 times the longest plan dimension, otherwise it will deflect under load and your bearing pressure underneath will not be uniform. So, if your raft...

Civil Engineering: prerequisite for a newbie structural engineer, Structural Engineering Basics

Structural Engineering Basics: Hi Talha, Yes, he should be able to design the simple elements you list, but he should do these by manual/hand calculations rather than by using computer software. Until an engineer understands clearly the basics of structural analysis and design it is...

Civil Engineering: RC water tank, Leakage around RC tank pipe outlet

Leakage around RC tank pipe outlet: Hi Wioyan, The best solution for this is to empty the tank (if you can), and after the concrete surface around the pipe is dry, apply a suitable sealant all around the junction of the pipe and the concrete. In future, a puddle flange should be incorporated...

Civil Engineering: Regarding Thesis, Raft vs Piled foundations

Raft vs Piled foundations: Hi Shahid, This is quite a specific topic, so maybe you will not find anything on Google. However, you will find references to the design of rafts and similarly to the design of piles. So long as the applied loading, and performance criteria (e.g. maximum...

Civil Engineering: reconstruction for a load bearing building, load bearing wall, cement mortar

load bearing wall, cement mortar, khartoum sudan: Hi Shehabaldin, 1. You expose it and inspect the concrete for any deterioration and expose the rebar to see if it is corroded. 2. Firm rock, in your situation, would mean continuous rock for at least 1m depth below the grade beam and capable of bearing...

Civil Engineering: rigid &semi rigid diaphragm, e tabs, building structures

e tabs, building structures, diaphragms: Hi Mohamad, Fot most building structures you should use semi-rigid daiphragms, as they best simulate actual behaviour, with small in-plane deformations. You can get full details of the difference between rigid and semi-rigid diaphragms by using the help...

Civil Engineering: steel construction, floor slabs, portal frames

floor slabs, portal frames, rc construction: Hi Zeeshan, This is a wide ranging question and you really need to read some books or browse on Google to get more details. But essentially, steelwork buildings are designed and made from factory made steel sections (H-columns or I-beam or C-channels, or...

Civil Engineering: Conversion of CBR to KN/M2, uni halle, kn

uni halle, kn, cbr: Hi William, I am not an expert in this subject but from what I know, CBR is used mainly for pavement/roads design and is based on values of penetration at the surface due to certain loads. This is not really convertable to safe bearing pressure for foundations,...

Civil Engineering: Cracking tests on high rise shear walls, Thick RC sections, heat of hydration

Thick RC sections, heat of hydration: Hi Rana, You did not tell me that the walls were 2.5m thick! This sounds very much like a heat-of-hydration early-age cracking problem and you should cease any further casting until measures are taken to prevent it happening again. There are some very...

Civil Engineering: cantilever slab design in etabs, etabs, slab design

etabs, slab design, flat slab: Hi Ravi, Just model it like any slab, but do not have any supporting columns at the outside edges. Maybe you will have cantilevering beams either side, and if the slab is supposed to span between these, then you can use the one-way spanning feature within...

Civil Engineering: column & Pillar, vertical loading, lateral loading

vertical loading, lateral loading, lateral load: Hi Faiz, In many cases these terms are interchangeable, but a column is usually subjected to mainly axial vertical loading, with some lateral load/moments, whilst a pillar is usually subjected mainly lateral loading (as a cantilever), with some axial vertical...

Civil Engineering: core wall design, shear core wall design

shear core wall design: Hi Abed, In simple terms, work out the total vertical loading (W)on the total liftshaft (from beams/slabs/stairs, etc spanning on to it + roof + machinery), and the total moment (M)due to eccentric vertical loading and lateral wind/seismic loading. Then...

Civil Engineering: Dynamic loads, earthquake loading, vibration characteristics

earthquake loading, vibration characteristics, response spectrum: Hi Sara, If you are talking about designing buildings, then the most common methods are to use Response Spectrum Analysis or Time History Analysis, both of which simulate the effects of dynamic earthquake loading- you can Google these and see lots of references....

Civil Engineering: ETABS trim and extrude, e tabs, etabs

e tabs, etabs, dividing lines: hi Jaya, Yes, you can trim by dividing lines or areas at intersections with lines or points and then deleting the bits not required. Similarly, you can extrude lines and areas by specified distances. Check out the help menu within ETABS for detailed instructions...

Civil Engineering: Fiber concrete, FRC, fibre reinforced concrete

FRC, fibre reinforced concrete: Hi Athula, FRC works by preventing micro-cracks within concrete and significantly increases the tensile strength of concrete. However, it is not used much for members that are subjected to high tensile stresses, such as long-span or heavily loaded beams....

Civil Engineering: Foundation on fill, ground beams, raft foundation

ground beams, raft foundation, differential settlement: Hi Masud, This depends on how well the fill was compacted and whether the compaction was done in layers of maximum 200-250mm thickness. If it was, then you could consider pad foundations with interconnecting strap (ground) beams, or if differential settlement...

Civil Engineering: structural analysis II, section modulus

Civil Engineering: structural analysis II, section modulus

Civil Engineering: Wind load in Tanzania, arshad khan, wind zone

Civil Engineering: Wind load in Tanzania, arshad khan, wind zone, meinert

Civil Engineering: Partition Load on slab, partition, slab

partition, slab, load: Hi Owais, If the partitions are lightweight (timber/fibreboard) demountable type, then you can assume a UDL of 1.0 to 1.5 kN/m2 over the whole slab, or affected slab. If the partitions are blockwork and you know the locations, then you need to work out...

Civil Engineering: Problems in erection of virendeel truss, bolt diameters, arshad khan

bolt diameters, arshad khan, roof purlins: Hi Narendra, You have not confirmed whether the base plates are rotating, but this sounds like your bolts are under-designed. I do not think the additional measures you mention will have much of an effect on the bolts problem. So try and use larger bolt...

Civil Engineering: Project topics, Project, final year

Project, final year, topics: Hi Sumit, If you had browsed my previous answers you would have found the following : Some topics I have listed previously are: 1. High strength concrete 2. Durability of concrete. 3. Optimisation of structures. 4. Punching shear in flat...

Civil Engineering: pile cap and bored pile design, pile cap design, design spreadsheets

pile cap design, design spreadsheets, ground beams: Hi Yusak, You can download the pile & cap design spreadsheets from this website: http://www.structural-engineering.fsnet.co.uk/free.htm However, for a single pile the column load should be concentric and then you will just need ground beams to resist...

Civil Engineering: Query in Civil Engg., Career Change in civil engineering

Career Change in civil engineering: Hi Talha, If you do not like civil enginering then I would not recommend Building Engineering for you as this is an extension of civil engineering, although you can make good money from it! Therefore, I suggest you pursue the other field of management/transport...

Civil Engineering: RCC Detailing- Long Span Beam, lap length, girder

lap length, girder, beams: Hi Syed, For your bottom bars, option 2 is better. For top bars, again it is better to stagger the laps. There is no need to weld the laps, so long as you meet code requirements, especially related to bundled bars. Remember that tying wires do not...

Civil Engineering: ribbed slab in ETABS, ribbed slab, etabs

ribbed slab, etabs, self weight: Hi Demo, The best way to model this is to define it as a membrane, with special one-way spanning, and then give it the following properties: Overall membrane thickness should be the equivalent thickness by adding in the 100mm flange and the ribs, averaged...

Civil Engineering: Spacer bar, Spacer, blocks

Spacer, blocks: Hi Rohan, There is no specific code specification for the spacing of spacers (bar or block. This really depends on the diameter of the bar and its orientation, so as to prevent excessive deflection and displacement whilst pouring concrete. (smaller diameters...

Civil Engineering: STRIP FOUNDATION Rebar, rebar, longitudinal direction

rebar, longitudinal direction, shear forces: Hi Thembani, That will have no adverse effect, so long as the main rebar is sufficient to resist bending and shear forces. In many cases of low-rise buildings both rebar may well be the minimum code requirement, so in this case it does not matter which...

Civil Engineering: structural analysis II, stress, z-value

stress, z-value, moment of resistance: Hi Virgilio, This sounds like a homework question, which I do not normally answer. However, you can work it out yourself by the following steps: 1. Work out the Z-value by deducting internal z= b*d*d/12 from the external Z=B*D*D/12 2. Use the formula...

Civil Engineering: structural mechanics, Structural, architecture

Structural, architecture: Hi Harmony, If you mean structural analysis and design, then the relevance is that without this discipline or input from this discipline, architects would not be able to design structures efficiently and would not be able to ensure the stability and safety...

Civil Engineering: Wind load in Tanzania, arshad khan, guestimate

arshad khan, guestimate, wind loads: Hi Marion, I am trying to find out for you from my contact in Tanzania, but for the moment I would hazard a guess that it would be around 35 m/sec for the 3-second gust speed. More later..... My contact has just responded as follows: There is a Tanzanian...

Civil Engineering: 8 dia not available, can fix 10dia , how, slab, rebar

slab, rebar, detailing: Hi Abdul, If you work out the cross-sectional area of the bars and multiply by the spacing, you get a similar area per running meter- i.e. 335 or 353mm2/m, as mentioned above. So long as the bottom bars extend past the support by at least same distance...

Civil Engineering: Brick Wall Modeling, movement joints, brick wall

movement joints, brick wall, etabs: Hi Sajeev, This is a bit difficult to model as brickwork properties at a diagonal are not well defined (depend on quality and grade of the bedding mortar, strength of brickwork, etc). If you are not relying on the wall for lateral stability, then just apply...

Civil Engineering: Cement floor tiles, steel slag, floor tiles

steel slag, floor tiles, blocks: Hi Satya, I would say that for use as floor tiles and blocks, your CCS tests would be sufficient- perhaps you should do some permeability too tests to ensure durability. I would also suggest you consult the loacl authority as they may have specific requirements...

Civil Engineering: concrete footing, steel piers, floor slab

steel piers, floor slab, brick column: Hi Alex, This really depends on how thick the floor slab is, what rebar there is in it and also how strong the foundation is. Without such info, it will be guesswork, but I would imagine that a line of brickwork around the column will not really exert a...

Civil Engineering: Cross beams + Raft & lift pits, raft, lift pit

raft, lift pit: Hi Ananta, 1. Where raft is lower than lift pit depth, then extend the liftshaft walls down to raft and either fill up the liftshaft with weak concrete, or else cast a suspended slab for the lift pit bottom strong enough to resist lifts impact loads. ...

Civil Engineering: etabs section cut, output tables, check boxes

output tables, check boxes, shear wall: Hi Tanvir, You can request the analysis outputs at any pre-deterined section cuts so that this appears in the output tables. This is explained in the Help menu, such as copied below: Analysis Output Form: Print Output Tables, Select Output Use...

Civil Engineering: RAFT SLAB ON DOWNSTAND BEAMS ON THE GROUND SURFACE, water table, ground water

Civil Engineering: RAFT SLAB ON DOWNSTAND BEAMS ON THE GROUND SURFACE, water table, ground water, raft

Civil Engineering: Final Year thesis topics, Final year, thesis

Final year, thesis, topics: Hi Ivy, If you had browsed my previous answers you would have found the following : Some topics I have listed previously are: 1. High strength concrete 2. Durability of concrete. 3. Optimisation of structures. 4. Punching shear in flat slabs....

Civil Engineering: Grade Slab, grade slab, ground slab

grade slab, ground slab: Hi Attaulla, If they are both supported by the ground/soil, then they refer to the same thing. Sometimes a ground floor slab can be a suspended slab, spanning between grade (or ground) beams, in which case that cannot be considered to be a grade slab, and...

Civil Engineering: Model a concrete wall, ETABS, basement walls

ETABS, basement walls, shear walls: Hi Sajeev, 1. Model it as a shell element, but in any case that will also behave like a shear wall. The base should be fixed, unless you have a very weak foundation or very thin basement slab. 2. You can model it with or without columns, depending on...

Civil Engineering: Point Restraint while modelling Raft, ETABS, piled raft

ETABS, piled raft, modelling: Hi Sajeev, If you have modelled a raft in ETABS, then the columns support restraint should remain as fully-fixed, as the raft is usually much stiffer than the columns. Yes, you can model a piled raft in ETABS- just increase the spring stiffness at the...

Civil Engineering: PREFAB STRUCTURES, Precast concrete, joints

Precast concrete, joints, details: Hi Baby, This should not be a problem so long as the joint is properly detailed. Please refer to these websites: www.world-housing.net/uploads/precast__concrete.pdf www.concrete.org.uk/services/fingertips_nuggets.asp?cmd...id... And this PDF is...

Civil Engineering: Punching Shear, punching shear, axial load

punching shear, axial load, close proximity: Hi Sajeev, With the dimensions you have indicated, if the column is right in the centre of 4 piles, then you are at the limit and will have to consider punching shear. If part of your zone of influence (at say 45 degrees down from footprint of column, between...

Civil Engineering: about QA and QC, Quality, assurance

Quality, assurance, control: Hi Yogesh, I am by no means an expert in this field, but logically I would say QA is to set up advance procedures and audit trails during the process to ensure quality to set standards. (such as specificatiosn for a contract) Quality control would then...

Civil Engineering: RAFT SLAB ON DOWNSTAND BEAMS ON THE GROUND SURFACE, raft slab, ground beams

raft slab, ground beams, grade beams: Hi Dennis, Firstly what you describe is not a raft slab, but a ground slab suspended between ground or grade beams. In this case, the slab is (as you say), a suspended slab and should bedesigned with both bottom (sagging) rebar and top (hogging) rebar at...

Civil Engineering: rcc beam lapping, side span, load combinations

side span, load combinations, bending moment: Hi Sunil, You basically have to do the analysis with all load combinations and design the rebar to curtail as per the bending moment diagram- main top rebar at supports (extending about 1/4 span in each direction) and for the cantilever main rebar for full...

Civil Engineering: rebar corrosion, carbonation, rebar

carbonation, rebar, steel corrosion: Hi Umair, Yes, the rebar is protected from rusting due to the alkaline present in the concrete. You are right that concrete is porous, which is why it is so important to have dense concrete and provide sufficient amount of cover. Over a period of time (many...

Civil Engineering: single beam to two slabs at different levels, ETABS, stepped slabs

ETABS, stepped slabs, beam: Hi Tanveer, If I was doing this modelling, I would just put the slabs at the same level, say at 2.9m level, as the overall effect for the analysis and design for the slabs will be minimal, and the only thing you need to consider when designing the beam...

Civil Engineering: Vibration problem, Base isolation, vibrations

Base isolation, vibrations, residential building: Hi Goni, The main structural safety/performance issue with this situation will be foundation material and danger of liquifaction- but this depends on whether you are in an area of fill or on sound bedrock. If the latter, then the main issue will become...

Civil Engineering: beams and columns, hydraulic device, device history

hydraulic device, device history, stirrups: Hi Jenny, Ties are mainly for columns and stirrups are mainly for beams. For both columns and beams they resist shear, but they also restrain compression rebar against buckling. Probably around 10% of manpower for all rebar- just a guesstimate. ...

Civil Engineering: career exploring, Civil engineering career questions answers

Civil engineering career questions answers: Hi Dindin, Civil engineering is an excellent career, but you will need to have an interest in the topics and also be good at maths, geometry, etc. The following Q&A from my past answers will give you an idea of what is involved: ************************************...

Civil Engineering: core test result, concrete strength gain age

concrete strength gain age: Hi Ravi, Firstly you should always take 3 core samples from each location to cater for coring/testing variances, and use the average for assessment. As for increase in strength, yes you can get quite substantial increase in strength with age (see graphs...

Civil Engineering: Honeycombing, honey comb, cement paste

honey comb, cement paste, shear capacity: Hi Vinod, If the hoenycombing is near the bottom of the beam and in the middle 1/3rd of the span, then you can simply grout it up with sand/cement paste. If it is near the supports, then there may eb a problem with shear capacity and you will need to be...

Civil Engineering: Lap lengths, Rebar lap lengths

Rebar lap lengths: Hi, The lap lengths depend on several factors, such as diameter, location (e.g. corner or face), whether there is bundling, what stresses there are in the rebar, etc. They will not be the same for columns and beams. I suggest you refer to appropriate codes,...

Civil Engineering: Soil Mechanics, Dry Density., Soil Dry Density

Soil Dry Density: Hi Andrew, I am not an expert in this field, but engineering judgement tells me that if you want a net dry density of the soil particles only (excluding the air voids within), then by taking the volume of wet soil (which makes the sample more compact and...

Civil Engineering: -ve reinforcement in cont. beams., shear failure, concrete section

shear failure, concrete section, shear resistance: Hi Manoj, What happens is that the top steel yields a bit, so beam rotates very slightly, with cracks in the concrete for the top half (or less)depth only, and this immediately sheds the moments to the span. The remaining concrete section of beam that is...

http://en.allexperts.com/q/Civil-Engineering-1357/2011/8/final-year-project-topics.htm

Civil Engineering: Gantry girder, moment of inertia, mid span

moment of inertia, mid span, transportation purpose: Hi Goni, 1. For use as a gantry beam, the only way you can keep the deflection within limits is to provide sufficent 2nd moment of inertia (i.e. Z value) and by using the highest grade of steel available. The former can be achieved by greater depth or thicker...

Civil Engineering: Hello !, Rooms clear heights

Rooms clear heights: Hi Vipul, They can be any height, depending on functional and architectural requirements. The minimum clear height for offices and accommodation is between 2.7 to 2.8m which translates to a floor-to-floor height of between 3.2 to 3.5m, although some buildings...

Civil Engineering: hollow pot floor, hollow clay, hollow blocks

hollow clay, hollow blocks, allexperts: Hi John, Please see my answer below: http://en.allexperts.com/q/Civil-Engineering-1357/2009/11/hollow-blocks.htm To add to that, the voids in the pots must be aligned parallel to teh span direction and the joints between the pots should be tight,...

Civil Engineering: Industrial Shed Expansion, framing system, direct wind

framing system, direct wind, wind loading: Hi Ravi, You may consider the internal column without direct wind loading, but of course the overall wind loading will be shared between the 3 columns via the portal action, unless the whole shed has roof X-bracing, taking the total wind loading to the...

Civil Engineering: structure neighbouring building, raft foundation, lateral pressure

raft foundation, lateral pressure, problem thanks: Hi Raju, This depends on the type of subsoil material- if it is rock or soft rock, you may not need to take any further precautions- if it is softer material, then the pressure bulb under the foundations (raft?) of the new building will influence lateral...

Civil Engineering: Sway of Monuments, Minaret sway limits

Minaret sway limits: Hi Waseem, That should be fine (235mm over 60m)- you could even accept a higher sway so long as your finishes, internal partitions and services can accommodate the sway without dislodging or suffering damage. This is on the assumption that there is no...

Civil Engineering: No. of Blocks, blocks in wall calculation

blocks in wall calculation: Hi Rashid, Assuming that the wall is 8 (inches?) wide, then basically you work out the elevation area of the wall first. Say it is 20 ft (240 inches) long and 10 ft (120 inches high). Then the face area is 240 X 120 = 28,800 sq inches. The net face area...

Civil Engineering: classes of concrete, Cylinder and Cube Strengths Comparision

Cylinder and Cube Strengths Comparision: Hi Azi, Yes, with the new system of classifying concrete, both the 28-day cylinder strength (20) and the equivalent 28-day cube strength (25)are quoted. So C20/25 is 25 N/mm2 cube strength at 28 days. The other grades will be similary quoted. The ratio...

Civil Engineering: column drop panel, axial column load drop panel

axial column load drop panel: Hi Kireeti, You need to work out the dead and live loads reaching the edges of the drop panel, (on all 4 sides), then the total of these will be supported by the column. The only additional axial load will the the extra dead weight of the drop panel, plus...

Civil Engineering: design of pile cap with single pile, pile cap, column base

pile cap, column base, axial load: Hi Shaik, In this case, just ensure that the column is central to the pile, but take accidental eccentricity into account, in addition to any column base moments and ensure that the pile can resist not only the axial load but also the moments near the top....

Civil Engineering: doubt about pile caps, flat slab with drop panels

flat slab with drop panels: Hi Kireeti, What you have shown in the picture are not piles and pile caps, but columns and column heads, or what are called drop panels for flat-slab design/construction, which do not require down-stand beams. This is a well established method of...

Civil Engineering: F22 and Pier Axial Force in ETABS, axial force, etabs

axial force, etabs, axial load: Hi Waseem, F22 is axial force per unit length (so if a pier is 2m long, say the F22 is 500 kN), then for the full pier the axial load will be 1000 kN. If the pier is subjecetd to in-plane moment (as most shear walls are), then F22 will vary from one end...

Civil Engineering: final year project, Stability of high rise buildings

Stability of high rise buildings: Hi Saddam, I would suggest that you do a project on comparing which lateral stability systems are most suited for different heights of buildings, such as 20, 40, 60, 80 and 100 storeys. The options for these are: 1. Moment resisting frame 2. Shear...

Civil Engineering: Footing design, Tie beam eccentric footing

Tie beam eccentric footing: Hi Chris (Dhanya?), Yes, you can use the inverted T-beam as a tie beam and design it for double curvature bending/shear due to differential settlement, which you will need to determine in conjunction with the soils investigation report. For eccentrically...

Civil Engineering: Force on a hinge, Gate hinge forces

Gate hinge forces: Hi Matt, You have not indicated the height of the gate, or more importantly the vertical distance between the, I presume, two number hinges. Let s say that distance is z ft. So, the 2 hinges will be subjected to vertical shear (assume both will be subjected...

Civil Engineering: Inverted beam design, Hanger stirrups slab at bottom of beam

Hanger stirrups slab at bottom of beam: Hi Chris, Simply work out the shear due to the slab at edge of beam and support that with additional steel rebar (hangers/stirrups), assuming they support the slab in tension. This additional hanger rebar will be additional to normal shear links. If the...

Civil Engineering: Joints in beam foundation, parallel beams, differential settlement

parallel beams, differential settlement, juan fuentes: Hi Juan, Did you mean 50m, or 500m? If it is 50m, you do not need any joints. If it is 500m, and if the beams are exposed to the weather (sun, etc), then you will definitely need to incorporate expansion/contraction joints at least every 50-75m centres,...

Civil Engineering: Lateral Earth Pressure combination, ACI 318 Chapter 9 section 9.2.1 (d)

ACI 318 Chapter 9 section 9.2.1 (d): Hi Atika, The way I interpret that is that when you use H in the the combos (e.g. with W and E), when earth pressure reduces the overall building lateral load, or reduces the global overturning moments, then it should be excluded from the combos. However,...

Civil Engineering: LEGAL STATUS OF SAUDI BUILDING CODE, usa standards, refernce

usa standards, refernce, dear sir: Hi Waseem, I have not worked in KSA, but I would assume that if you do not comply with it you will not get local authority approval of your designs and drawings. I have studied the code and find it very comprehensive and more or less up to date with international...

Civil Engineering: Moment Redistribution, beam section, seismic loading

beam section, seismic loading, stiffness: Hi Sirisha, Moment re-distribution occurs when you have high support (hogging) moments in beams and low span (sagging) moments at or near midspans. This then causes some cracking in the concrete at the supports (both elastic as well as long term creep/plastic),...

Civil Engineering: project on seismic vulnerability of buildings, seismic vulnerability, india code

seismic vulnerability, india code, vulnerability assessment: Hi Namrutha, Your topic can be quite technical, if you go deeper into assessing the aseismic design and construction of the buildings. for example, you could look into soft stories, infill blockwork, etc, as such things have a big impact of the seismic...

Civil Engineering: ribbed slab, ribbed slab

ribbed slab: Hi Daniel, You have not really asked a question, but if you want details about this form of construction, please browse my past answers http://en.allexperts.com/q/Civil-Engineering-1357/2008/11/Ribbed-slab.htm http://en.allexperts.com/q/Civil-Engineering-1357/2008/11/RIBBED-FLOOR-CONSTRUCTION.htm...

Civil Engineering: shortening of concrete columns, spreadsheet column axial shortening

spreadsheet column axial shortening: Hi Robert, Yes, the RCC in UK sells one at their website: http://www.concretecentre.com/online_services/design_tools/rc_spreadsheets_v4.aspx You can also download a free earlier version from the web. The limitaion is for 24 storeys, but you can get...

Civil Engineering: Steel quantity extract from Etabs, tonnage, laps

tonnage, laps, quantities: Hi Phani, As far as I know, ETABS does not output rebar quantities/tonnage after design (as STAAD.Pro does). However, you could estimate it from the rebar areas that it outputs (after completing the design process), by multiplying the longitudinal areas...

Civil Engineering: tie beam, wall joint tie beam

wall joint tie beam: Hi Ananta, I am not sure if I fully understand your question, but if you have 25m of wall, with one intermediate column at the middle, then your wall is already split into two halves. Then you can have 2 options for the tie-beams at the top of the wall-...

Civil Engineering: Alignment and size of columns, footing size, quality

quality: Dear Vish As you might guess , this is not a question I can give you prompt and explicit answer. Please take some high quality photo and send me. No problem with the depth of foundation but the size of columns and also the quality, I am anxious, like yourself....

Civil Engineering: Civil Engineering beams., cement brick

cement brick: Dear Venkat With the type of building I see in your picture you can use 25x25 Reinforced Concrete Columns with 4 x 14 mm diameter rods and stirrups d=8 mm @ 250mm huging 4 longitudinal rods. Strength of concrete must not be lower than 20 MPa. I hope...

Civil Engineering: saw dust as sand in concrete, Concrete admixture

Concrete admixture: Dear Sharmila Concrete admixture is very serious even for moderate range of strength. Saw dust cant replace sand in concrete and sand cant replace gravel. I suggest this formula to be tested ( this is not very accurate but a guide) : 600-800 kg gravel...

Civil Engineering: Earthquake Drift Limits, earthquake loading, return period

earthquake loading, return period, 7w: Hi Waseem, Normally you do not apply the reduction factor in the combo, but look at the output drifts and then apply appropriate factors to see if they fall within limits. The factors depends on some variables- please refer to UBC-97 clause 1630.10 and...

Civil Engineering: ETABS, reliability

reliability: Dear priyantha 1- Structural design is an art : to use loadings which are not known exactly, in a combination which is not known exactly , to analysis of structure assuming a simple model instead of the real building located on the soil without knowing...

Civil Engineering: Finite element modelling, composite, research

composite, research: Dear Joseph 1- What is a composite deep beam? you mean a mix of reinforced concrete slabs and steel profiles? Please explain me to know! 2- This topic needs a general knowledge about finite element,also a specific knowledge about structural finite...

Civil Engineering: Foundation design, tank

tank: Dear Barek Sorry for delay. You can follow these links http://www.ce-ref.com/pile_cap.htm http://en.allexperts.com/q/Civil-Engineering-1357/pile-cap-design.htm http://www.icjonline.com/views/POV_Nori_Apr2007.pdf http://www.scribd.com/doc/56617390/Pile-Cap-Design...

Civil Engineering: g=9.8 m/s^2, unit conversion, acceleration

unit conversion, acceleration: Dear Surajlaghe This is an experimental value. But I admit that if we would be in another planet like Venus , or Uranus the specific acceleration of gravity would change the definition and identification of force unit. In actual situation we have to use...

Civil Engineering: Holes through plinth beams, drainage pipes, hole diameter

drainage pipes, hole diameter, water pipes: Hi Ravi, This depends on how deep the plinth beams are and what diameter and location of the holes are. If the hole diameter is less than about 1/4 depth of beam, and the holes are cut within the middle 1/3rd height of beam and within middle half of the...

Civil Engineering: lift core foundation, pile, mat

pile, mat, lift: Dear Barek I cant understand why you want a pile system for a lift core, because usually the loading of lifts are not so serious unless you have a very bad soil situation or essentially you want it for your shear walls not for your lift. However you can...

Civil Engineering: pile reinforcement, spacer bars blocks

spacer bars blocks: Hi Liaqat, Spacer bar is usally specified where you have 2 or more layers of rebar next to each other and you need to leave space between them for concrete to fill the space for achieving good bond. Normally spacer bars are about 20 to 25mm diameter....

Civil Engineering: Pile top movement, pile

pile: Dear Ananda hi, you will have to deal with an axial (tension) loading. You have to be careful when watching your test process , my idea is to reach to your loading test, if your test process shows that you will never each to your target loading , your test...

Civil Engineering: project help, Design

Design: Dear Nikitha It is hard to reply such a question , but generally you must be aware of some points: 1- The projects must have an architectural team. 2- A preliminary phase report issued by architectural team will guide you through loading and construction...

Civil Engineering: project managment, management

management: Dear Kuldeep It is very much dependent on your talents and targets, but I think You can reach your goals through Project Management. Its is more extensive and will give you the basic knowledge you will need in a construction management, too. Regards...

Civil Engineering: RC DESIGN, deflection, vibration

deflection, vibration: Dear Priyantha The main feature one has to consider in design of long span slabs and girders is the limitation of deflection + vibration control of roof if it is subjected to human live load. Then you must provide your system with enough stiffness to reduce...

Civil Engineering: Reinforce concrete design, design

design: Dear Joseph It is hard to reply such a question , but generally you must be aware of some points: 1- The projects must have an architectural team. 2- A preliminary phase report issued by architectural team will guide you through loading and construction...

Civil Engineering: reinforced concrete column construction related, anchorage, chemical

anchorage, chemical: Dear Imtiaz Ahmed In the case your waiting reinforcement( for overlap) being lost , you will be obligated to use chemical anchorage of new bars in your columns to provide a fresh set of reinforcement to extend your building. The technology is not expensive...

Civil Engineering: Shear Enhancement, shear, enhancement

shear, enhancement, concentration: Dear Sirisha Shear enhancement is not a very popular expression to explain about the critical shear stress in beams and girders near supports or in the case of shear stress concentration in the case of discontinuities in columns vertical alignment and so...

Civil Engineering: Stiffness Reduction & Property Modifiers, Stiffness modifiers

Stiffness modifiers: Hi Waseem, Before asking me a question I would encourage you to please search my past answers, where you would have found: QUOTE: Subject: section modifier in reinforced conc. shear walls Question: QUESTION: dear sir I want to know your opinion...

Civil Engineering: strength of materials, Strain, Rosette

Strain, Rosette, stress: Dear Kireeti Please take a look at this link: http://www.efunda.com/formulae/solid_mechanics/mat_mechanics/strain_gage_rosette.cfm When measuring strain and stress on a material under loading a single strain gage with a definite orientation angle...

Civil Engineering: structural analysis using ETABS, diaphragm, rigid

diaphragm, rigid: Dear Priyantha 1- In the case you dont use a solid diaphragm, loading on each node will be absorbed by the structural element in the right vicinity of loading.If you have only a shear wall in your structure , the loads applied directly on shear wall will...

Civil Engineering: structural design using ETABS, shear wall

shear wall: Dear Priyantha 1- For foundation design , considering moment and axial load is more conservative than axial load alone. 2- you can have 2 types of surface elements : A- one with only in plane stiffness a bit like a balloon, but with compression and...

Civil Engineering: test for steel, Steel, test

Steel, test: Dear Mirza ayyub Ali Baig Hi, There is a wide range of testing each of test is specified for a purpose like: - Chemical Tests to define the ingredients of specific steel alloy and to identify the steel type - Physical Tests to govern yielding strength,...

Civil Engineering: thesis methodology, thesis, proposal

thesis, proposal: Dear Anna According to my own experiences you can follow the below mentioned trajectory, but you can have your own method regarding these guidelines: 1- to have a wide look on related literature, like papers and handbooks. Fortunately nowadays you have...

Civil Engineering: application of connectivity in software, Bridge support conditions ETABS

Bridge support conditions ETABS: Hi Mohammad, If you apply continuity in slabs between the two towers there is no point in doing releases for the beams, as that is incompatible. I presume that you do not wish to connect the 2 towers to act together laterally, in which case I would suggest...

Civil Engineering: Basics.., job, work

job, work: Dear Roy Dont fear about this matter. Basically you need to have academic knowledge. The second is to forget that you have such a foundation and get into the project and site and observe everything, third you need to have interview with stuffs. Your duties...

Civil Engineering: Breaking concrete pillar, span, retrofit

span, retrofit, moment: Dear Ahmed Every modification in the building structure must be done based on accurate calculations and under supervision of professional engineers. For your case increasing the lateral spans by 3 feet (30% of initial span) may be dangerous because of...

Civil Engineering: Cement, cement, granular

cement, granular, material: Dear Suraj Don t use unsound cement as cement anywhere. You can use it as filler material and where no strength from cement is expected, like basement of pavement. As a whole you would treat out of standard cement as granular materials, like gravel and...

Civil Engineering: civil engineering, project

project: DEAR Abraham Here are some topics for your interest. 1- Construction sequence and its effect on global reliability and behavior of the structure 2- friction based bracing and its usage on seismic design of structures 3- Energy dissipation devices and...

Civil Engineering: concrete, rc structures, toodle

rc structures, toodle, dowels: Dear toodle You must provide reinforcement equal to the reinforcement of the column itself in foundation. The length of dowels ( or stump as you say) are equal to about 50 times the diameter of the rods. They have 90 degree hook in their end buried in...

Civil Engineering: concrete, evaporation, concrete

evaporation, concrete: Dear Chaitali Not very sure about what you need really but we use plastic covers to protect the concrete against evaporation and water loss in concrete admixture. The play the role of protecting concrete against wind which is very dangerous for fresh concrete...

Civil Engineering: Concrete Volumes and Structural Design, Bulking and concrete cover

Bulking and concrete cover: Hi Amit, 1. That is the ratio by which sand or similar material increases in volume when it is wetted. such a factor would not apply to coarse aggregates, which do not bulk up when wetted. 2. That is because of thermal mass to dissipate heat during a...

Civil Engineering: design of load bearing masonry structure, masonray, design

masonray, design, etabs: Dear Vivek You would better develop a software in excel to design a masonry building. You can use etabs for some analysis and introduce the results to your program for design purposes. Please let me know about any question you would have. Regards BE...

Civil Engineering: Earlier question regarding quantity, cubic meter, mortar

cubic meter, mortar, cement: Dear Ibrahim Calculate the volume of the walls (say Vw) volume of mortar (including lost mortar) (Say Vm) = 15% Vw Weight of cement (say Wc) = 150 kg per volume of mortar (in m3) volume of stone (Vs) (including lost stone) = 100% Vw then...

Civil Engineering: Etabs Program civil Engg., ETABS to SAFE export LL reduction factors

ETABS to SAFE export LL reduction factors: Hi Mohammad, LL reduction factors in ETABS apply mainly to vertical elements, so if you export a floor slab to SAFE, then that is irrelevant for the design of slabs and beams. In any case, LL reduction factors in ETABS are used only for design forces,...

Civil Engineering: ETABS - Redistribution of Torsional moments, etabs, torsion

etabs, torsion: Dear Kiran I don t see such a modifier 0.2 in etabs. It is up to user to choose his own modifier. But in ACI the moment modifier is o.35 for beams either for flexural or torsional moment. Please let me know about the 0.2 modifier you claim about. ...

Civil Engineering: planted column on ETABS, floor slab, construction stages

Civil Engineering: planted column on ETABS, floor slab, construction stages, auto construction

Civil Engineering: Waffle pod design, slab, mesh

Civil Engineering: Waffle pod design, slab, mesh

Civil Engineering: final year project topic, Final Year Topics subjects thesis

Final Year Topics subjects thesis: Hi Enemona, If you browse my past answers with keywords final year topic thesis subjects , you will find lots of ideas. One such answer is as below, but if you need further advice, please get in touch again. Some topics I have listed previously are:...

Civil Engineering: find moment of resistance., rebar, strength

rebar, strength, deviation: Dear Ananta No software I know in this field, but I suggest you to follow this way and formula: strength deviation = RF ratio . depth ratio . initial strength for instance suppose the initial strength being = 10 T.m, 20% of reinforcement is subjected...

Civil Engineering: forces, wind velocity, wind forces

wind velocity, wind forces, flowing water: Dear Priyantha please consult related codes of practice. But for your own knowledge you can calculate the range of forces following this method: 1- Hydrostatic forces ( depth of water) which is a triangular force. 2- forces due to velocity of water...

Civil Engineering: foundation on rock, Minimum size of pads on rock

Minimum size of pads on rock: Hi Priyantha, Just ensure that the pad size is sufficently big to ensure development length of rebar from the supported columns, but otherwise you can make them as samll as the analysis/design permits, taking account of overturning moments to prevent tension...

Civil Engineering: master thesis, thesis, procedure

thesis, procedure: Dear Fidan First of all you need to have a global and specific survey on existing literature, like textbooks, papers and so on. This will provide you with about 20% of the volume of your thesis. You will get familiar with research topic reading others papers....

Civil Engineering: Method Statement for sheet piles, sheet, pile

sheet, pile, offshore: Dear Ahmed Please take a look at following link. It may be really helpful. http://books.google.com/books?id=2lm5zXTivm4C&pg=PA331&lpg=PA331&dq=sheet+pile+offshore&source=bl&ots=ToyhtXW_Y6&sig=k0uKHjw5gn1ZuMVpuLFSbmTE9g0&hl=fa&sa=X&ei=LB98UMr0HInesga9yYGQBA&ved=0CC8Q6AEwAg...

Civil Engineering: Modulus of subgrade reaction, Raft analysis

Raft analysis: Hi Syed, That approach sounds right but you must make sure that overall the net pressure (average) under the raft does not exceed the safe bearing capacity and that the maximum is not more than about 25% above the safe bearing capacity. You should do...

Civil Engineering: Perspective drawing, perspective, piping

perspective, piping, architecture: Dear surajlaghe A civil engineer must be able to show all details in 2 dimensions. But in mechanical drawings specially in piping details perspectives are useful to show the direction of pipings. Again in architectural drawings and to show the esthetic...

Civil Engineering: piling for retaining wall, contiguous piles

contiguous piles: Hi Ravi, This is not really my area of expertise, but I would imagine (depending on soil conditions and adjacent properties) that you should use contiguous bored piles around the perimeter from the ground so that these can form temporary supports for the...

Civil Engineering: planted column on ETABS, planted, column

planted, column, slab: Dear Khalid Due to the fact that your slab has been deflected downward then no loading is transferred to your planted column. But only the extra loading will be divided between slab and the planted column. This extra loading which is shared is the effective...

Civil Engineering: Project title for FYP, friction, variation

friction, variation, properties: Dear Ezy Please have a concern about following subjects: 1- Construction sequence and its effect on global reliability and behavior of the structure 2- friction based bracing and its usage on seismic design of structures 3- Energy dissipation devices...

Civil Engineering: PROJECT TOPIC IN HIGHWAY ENGINEERING FOR TROPICAL COUNTRIES LIKE NIGERIA, thesis

thesis: Dear Adeoluhwa The first step is to select your topics and subjects to study. 2- Do search on Internet and find key papers in your favorite topic 3- study the papers and make a summary of each. 4- Ask your teacher to explain about any question a or doubt...

Civil Engineering: Proportional Limit Stress vs. Ultimate Tensile Strength, tensile, limit

tensile, limit, elastic: Dear Edward The maximum allowable load shall be calculated using : Pa= SF.(UTS or Fy).d^2*3.14/4 SF = 0.6 for Fy and o.5 if you use UTS ( Fy being yielding elastic limit , UTS being collapse limit). The basis of calculations is Fy usually. No...

Civil Engineering: rc retaining wall, soil, nail

soil, nail, active: Dear Priyanta I think it is better to concentrate relatively the nailing at 1/3 of the height of the wall. But a certain propagation of nails around this center would have integration effect. I suggest you to perform a finite element analysis using ansys...

Civil Engineering: regarding footing, lift, foundation

lift, foundation: Dear Kavikumaran Usually lifts are installed in roof level or so. Then you need a foundation not to support the motor and gear box but for the impact force due to falling down of lift case. It is a 2x2 m2 spread footing (for your case) or a mat foundation...

Civil Engineering: Residential building, masonry, design

masonry, design: Dear joyanta Take a look at following links: http://www.iitk.ac.in/nicee/IITK-GSDMA/EQ10.pdf http://www.boral.com.au/masonry-design-guide/masonry%20design%20guide%20home.asp http://armypubs.army.mil/eng/DR_pubs/DR_a/pdf/tm5_809_3.pdf This latest...

Civil Engineering: rock anchoring, hilti, bolt

hilti, bolt, anchor: Dear priyantha May be you would need to anchor, but not always. It depends on your calculation and the analysis of forces acting on the structure. Usually anchoring is chemical and sometimes mechanical. I refer you to Hilti products for information about...

Civil Engineering: soil mech, clay, sand

clay, sand, ash: Dear Suresh I feel you are not satisfied with my response. Please let me know what is unclear or unsatisfactory for you. Regards BEH Dear Suresh In laboratory we do a test called SE. In this test the amount of clay and silt and sand will...

Civil Engineering: spandrel beams in shear walls, shear, wall

shear, wall, spandrel: Dear Shahid The opening make a weak point inside shear wall area and the elements below and on the top of opening get in a flexural behavior which must be design for. The ductility of such a beam is very important for seismic design purposes. Regards...

Civil Engineering: structural analysis related research topic, design, structure

design, structure, concrete: Dear Tanu In structural engineering you can get evolved in several topics and get expertised 1- Design of R. concrete structures 2- Design of Steel Structures. 3- Advanced analysis for complicated structures. 4- Design of Bridges 5- Design of dams...

Civil Engineering: structural dynamics, damping, period

damping, period: Dear Deshmukh When you introduce some soft spring between your structure and the ground(base isolation ) , the total stiffness of the structure reduces and then you will have softer structure, i.e. higher period. But the effect of damping is to reduce the...

Civil Engineering: structural engg, expansion, joint

expansion, joint, seismic: Dear varghese expansion joints must be able to allow independent sway between 2 structures when differential temperature occurs and also in seismic action. You have to convince yourself about the efficiency of the material you use. Regards BEH ...

Civil Engineering: am student of senior high., cover, concrete

cover, concrete: Dear Richard Cover has 2 main roles: 1- to protect outer reinforcement against corrosion. 2- to provide the steel bars with good cohesion to make sure about good combined behavior of concrete and steel. If no surrounding concrete exist no tension stress...

Civil Engineering: Thickness of Aluminium Profile for Window and Doors, aluminium, window

aluminium, window, consultant: Dear Nishant You must contact your formal consultant, because this is their duty to clear this. But as an advice I suggest you to take a look at the vendor references and have correspondence or direct conversation with customers to be sure about the quality...

Civil Engineering: Waffle pod design, slab

slab: Dear Ralph The details you gave me are not clear. For example I don t know the span of your slab, the size and distance of the rods used for reinforcement and also the mechanical properties of concrete and steel , and so on. Please provide me with as much...

Civil Engineering: 2 way cantilever slab, slab, concrete

slab, concrete, calculation: Dear Ali This is a 2 way slab you should suppose it as a one way slab behaving diagonally. The length to be considered for a cantilever slab is half the diagonal. Then you must distribute the reinforcement on the top of the slab in x and y direction. X an...

Civil Engineering: Beam Loading from slab & point load, slab point, secondary beam

slab point, secondary beam, main beam: Hi Ali, Its seems that you need to study some technical text books, as these are basics of structural engineering: 1. For the shorter span beam, there will be some loading from part of the slab, which on plan will be triangular in shape. Or you can assume...

Civil Engineering: Best structural connectivity, Fatigue in concrete

Fatigue in concrete: Hi Mohammad, If you think about it, a rigid connection in RC relies on the rebar for all tensile (& possibly compressive) resistance when bending, so it will be the rebar that will be subjected to cyclic loading. As for the concrete, I do not have any...

Civil Engineering: A career in civil engineering, Career questions Civil Engineering

Career questions Civil Engineering: Hi Sophia, I have answered these types of questions before, so if you do not mind, I will cut/paste the Q&A for these below: As for Q1, I wnet to Bath University for my BSc and Imperial College (University of London) for my MSc. If you still have any...

Civil Engineering: Civil Engineering Dissertation, solar, passive

solar, passive: Dear Kiaser I don t have idea about concrete recycling . But in the field of solar energy , I suggest you to have a look on Passive solar systems, instead of solar panel which are not economically adjustable. You can work on solar supported ventilation...

Civil Engineering: Construction of retaining wall in 5 metre lifts, construction of retaining wall, high pressures

construction of retaining wall, high pressures, thanks in advance: Hi Suprio, A 5m pour is quite deep so you need to be sure about the formwork due to high pressures and also ensure that the concrete pouring for the lower half is done either by pumping or by use of chutes, as concrete dropping more than 2-3m can lead to...

Civil Engineering: Deflection combinations in ETABS, design combinations, gravity loads

design combinations, gravity loads, load combinations: Hi Waseem, This depends on what deflections you are checking- if it is beams, then just gravity loads will be sufficient, but if it is drift/sway then you need to also apply lateral loads. Refer to the code you are complying with and the service load combinations...

Civil Engineering: DET, release, moment

release, moment, hinge: Dear Mojtaba For a moment free connection you should bend lower and higher reinforcement to make sure all bars passing and interconnecting on a straight line ( moment release in one rotation direction) or an almost single point ( moment release in 2...

Civil Engineering: Diaphragm Action, shear, wall

shear, wall, diaphragm: Dear Riyaz You can do what you want in structures provided that you calculates the effects and consequences. The provisions in codes are to help engineers to calculate and design more easily. In your case you shall make use of flexible diaphragm or to make...

Civil Engineering: Dissertation subject, Slabs economy comparision

Slabs economy comparision: Hi Joao, Yes, you could do that (as has been done by others before) but if you make the comparisons specific to your location then you may well end up with different conclusions- for example, a slab with down-stand beams may well be more economical where...

Civil Engineering: Dissertation theme slabs, slab, plastic

slab, plastic, analysis: Dear Telmo I suggest you to follow this subject: Simplification and categorization of data gathered in Plastic analysis of slabs. In this method you should use plastic hinges to predict the collapse mechanism of slabs. The energy method is the key of...

Civil Engineering: Dual System on Etabs, SEAOC dual system guideline

SEAOC dual system guideline: Hi Syed, I guess the approach mentioned there can be used, but you should also read the caveat in the commentary at the end. If you want to proceed then yes, use the links method, but then you will not be able to accurately model the MRF interaction...

Civil Engineering: earthquake design, earthquake, design

earthquake, design: Dear deshmukh 1- Seismic design is based on collapse prevention and life safety under maximum credible earthquake . Then inelastic behavior under MCE or DBE (design basis earthquakes) level of earthquake. almost all codes accept this principle. 2- Seismic...

Civil Engineering: ETABS, diaphragm, slab

diaphragm, slab, degree: Dear mahmoud Diaphragm is an ideal rigid model which is adopted to model the slabs. When considering diaphragms some degrees of freedom get constrained together, like you can accept that the x drift of all joints in a level being equal ( when no torsion...

Civil Engineering: Etabs based column design problem, ETABS columns rebar

ETABS columns rebar: Hi Ahetesham, The columns design is based on the interactive diagram, which means that the critical design may not be based on the highest axial load, but with combination of axial loads and moments. I suggest you look at the design for all the load...

Civil Engineering: Dual System on Etabs, moment frame, shear wall

Civil Engineering: Dual System on Etabs, moment frame, shear wall, shear force

Civil Engineering: Foundation, column point, shear wall

column point, shear wall, corner columns: Hi Mohammad, Yes, in principle if you spread the load from a column point load to a more distributed line load (under shear wall), or perhaps making the corner columns into an extended L-shape (and hence make the base area much bigger), then your applied...

Civil Engineering: Fresh graduate on site, roles responsibilities for site engineer

roles responsibilities for site engineer: Hi Roy, A fresh graduate in an office will learn about practical aspects of his design and how buildable it is. So when you go on site, the duties you will have include: 1. Checking drawings and checking clashes between architectural, structural and...

Civil Engineering: general, waste water engineering, dam engineering

waste water engineering, dam engineering, highway engineering: Dear Deshmukh You have a lot of alternative to think about: 1- Structural engineering 2- Water and waste water engineering 3- highway engineering 4- dam engineering 5-.... 6- project control 7- design 8- contracts I suggest you to start...

Civil Engineering: Linked Elements, End releases for beams

End releases for beams: Hi Mohammad, I don t think you need to use Linked elements, as you can easily so the end-releases for the frame section (beams of bridges) as noted below in the ETABS Help menu. QUOTE Any of the three translational and three rotational degrees of freedom...

Civil Engineering: noise reduction for brick making machine, Sound insulation for machinery

Sound insulation for machinery: Hi Billbixby, This is not really my area of expertise but I would imagine that if you build a solid building around the equipment with say 150-200mm thick fibre wool (or low density expanded polystyrene) insulation on the inside walls and ceiling and without...

Civil Engineering: Preferable structural connectivity, stability, redundancy

stability, redundancy, plastic: Dear Mohammad Feelings of an engineer are very important facts governing a design, because you cant calculate all effects and investigate them with a calculator. But I have a magical tip which is helpful for me most of the times. I consider the structure...

Civil Engineering: RC slab on peripheral beam-support condition, Slab fixity to peripheral beam

Slab fixity to peripheral beam: Hi Ali, This depends on how the slab is fixed to the beam (is it cast monolithically with the beam?) and also how torsionally stiff the beam is. To be on the conservative side you should consider it as simply supported, but in practical situations there...

Civil Engineering: Reponse Scaling for Drift, ASCE 7-05 seismic drift R Cd

ASCE 7-05 seismic drift R Cd: Hi Waseem, For RSA you need to apply scaling factors so that the base shear is within 90% of that from a static analysis. This scaling can be higher or lower than 1g/R, but you should start with that factor and adjust as necessary. Once you obtain the...

Civil Engineering: retaining wall, Rubble stone retaining wall

Rubble stone retaining wall: Hi Priyantha, The principle is based on angle of friction of the material being retained by the lower floor, so that the pressure bulb under the higher wall does not impose additional lateral loading on the wall below. If the upper wall is closer to lower...

Civil Engineering: retrofitting, ductility, strength

ductility, strength: Dear Deshmukh Please notice a couple of things: 1- Ductility demand of the structures decreases with the stiffness. When you add shear wall into your structure, you increase the structure stiffness. Then you will need to have more ductility in your building....

Civil Engineering: retrofitting, retrofitting, drawings

retrofitting, drawings: Dear Deshmukh You must use as built drawings. If you don t have access to as built drawings you must make drawings according to actual situation of the structure. After that you must calculate the actual strength of members according to drawings. Regards...

Civil Engineering: safe 8 software, SAFE & raft & retaining wall

SAFE & raft & retaining wall: Hi Mohammad, No, in this case, the raft is not supported by the retaining wall- it is the opposite, as the retaining wall is supported by the raft, but the wall will provide additional stiffness to the raft in the vertical plane. The soild bearing pressure...

Civil Engineering: sap 2000, sap2000, structure

sap2000, structure: Dear Nouman You can apply loads in 6 direction , X, Y, Z and rotation around X, Y , Z Then you shall decompose your loading in this 6 direction first and then apply them. You can define whatever section you need in sap2000. For this reason you must...

Civil Engineering: shaft design for lift, lateral stiffness, shaft design

lateral stiffness, shaft design, steel shaft: Hi Ravi, This depends on what else is spanning on to the lift from surrounding structure. Just work out all the loadings in the 4 corner columns, then provide cross-bracing on all 4 sides to give the shaft lateral stiffness against wind/seismic forces...

Civil Engineering: slab design, etabs, safe

etabs, safe: Dear Sama 1. Not very clear question , but you would assign slab properties . Usually it is not needed to use modifier different than 1. I have seldom used the modifiers other than one. Modifiers change the stiffness and properties of the finite element...

Civil Engineering: Slab edge support on walls, edge support, safe side

edge support, safe side, ali: Hi Ali, If the walls are thicker than the thickness of the slab,and if there is no chance of them spalling or lifting due to slab trying to rotate, then you can consider the support as fixed. But if you want be be on the safe side, consider it as partially...

Civil Engineering: slab reinforcement, Beam column fixity; slab rebar spacing

Beam column fixity; slab rebar spacing: Hi Ali, 1. The minimum spacing and sizes of rebar are dictated by not just strength requirements but also for shrinkage/curing cracks and fire-resistance. Hence rebar may need to be even closer spacing than 175-200mm. 2. That depends on the rebar detailing...

Civil Engineering: Sloped rcc slabs, slab, deflection

slab, deflection, thickness: Dear sf The minimum thickness of slabs is governed by constructional limit and the maximum deflection allowed by codes of practice. You can look up ACI or BS for this purpose. I can give you a very rough criteria. The thickenss of slabs shal not be considered...

Civil Engineering: structural engineering, wall, stone

wall, stone, bearing: Dear Veena If the walls are bearing the weight of above roof , you shal use at least 14 brick wall, otherwise you may have to use UCR walls. If the walls are self supporting and bear onley their own weight you can use a 14 brick wall. Regards BE...

Civil Engineering: Structural-related thesis topic, beam, column

beam, column, seismic: Dear Guia Please try the following subject: Effect of oversrenghtening and /or oversizing of beams on stability of columns designed based on seismic provisions. Please don t hesitate to ask further questions to clear the points. Regards BE...

Civil Engineering: Subgrade reaction in mat foundation, global coordinates, global direction

global coordinates, global direction, etabs: Hi Ahetesham, It is difficult to say without interrogating the model, but I would suggest you try the following changes, one at a time, and see how the output is affected: 1. Remove the restraint for rotaion about the Z-axis. 2. Move the origin to...

Civil Engineering: thesis topic, fuzzy, genetic

fuzzy, genetic, algorithm: Dear Hubedin You can look up my comments in expert to find what you might need. But I can suggest a subject for your interest here: - Optimization of material consummation in reinforced concrete structures : A case study of 5 story building. The research...

Civil Engineering: Analysis & design books BS8110, reinforced concrete design, high rise buildings

reinforced concrete design, high rise buildings, bs 8110: Hi Meda, One of the best ones is this one which it appears you can download: http://shalikamanoj.weebly.com/uploads/1/0/9/1/10917131/62871222-design-detail-to-bs-8110-1997.pdf It has all the important code clauses and the format/layout of calculations...

Civil Engineering: Building Frame System, Dual MRF system

Dual MRF system: Hi Syed, If your frame system is stiff enough to resisit at least 25% of the base shear, you can design that as a dual system together with the shear walls and apportion the lateral forces accordingly. If the frame uis not very stiff (e.g. if you have flush...

Civil Engineering: civil engineering, Continuous beams rebar laps

Continuous beams rebar laps: Hi Nasir, This really depends on the bending moment diagram, which depends on loading and relative spans either side of the beam being detailed. However, assuming uniform loading and equal spans, the rule of thumb is to lap top bars within the middle third...

Civil Engineering: civil engineering, high strength concrete, flat slabs

high strength concrete, flat slabs, thesis subjects: Hi Saritha, Blast-proof buildings need special analysis methods and then special design using either confined concrete detailing or using special spiral rebar of twisted plates reinforcement. Yes, you can study beach sand, which requires special cleaning...

Civil Engineering: Concentric Giant Wheel Design, ferris wheel, physics

ferris wheel, physics, civil engineering: Prashant, Q: Is it possible to construct or manufacture Concentric Giant Wheels ? A: I do not see why it is impossible, given that it has already been constructed. Also, with the right engineering analysis it is highly possible. There have been far more...

Civil Engineering: Concentric Giant Wheel Design, wheel, dynamic

wheel, dynamic, static: Dear Prashant Sorry for my delay. This is not my very speciality. But I think it is like all other structures and you can go for it. The big problem in giant wheels is to have an analysis of the dynamic behavior of the wheel and its consequences. Then...

Civil Engineering: Design Columns without moments, column, moment

column, moment, axial: Dear Hamdi All codes allow you to design columns, sometimes with a concern of a minimum eccentricity. The formula in codes allow you to have a column with axial load only. But due to random eccentricity which may always occur, it is not recommended to...

Civil Engineering: Difference between light, medium and heavy steel., Field labour rates for structural steel

Field labour rates for structural steel: Hi Mike, I am not an expert in this particular subject but logically this would mean large size (say more than 10-12 inches) I-beams and H-columns for the heavy sections and small (say 2-6 inches)cold-formed Z-purlins, L-shaped angles, C-shaped channels...

Civil Engineering: expansion joints, High-rise expansion joints

High-rise expansion joints: Hi Naresh, This depends on a number of factors such as whether you are in a seismic zone, how long the structures are between joints, the expected temperature variations and also how tall the buildings are and what R factor us used in the design. If...

Civil Engineering: Analysis & design books BS8110, manoj

Civil Engineering: Analysis & design books BS8110, manoj

Civil Engineering: RC buildings, civilengineer, reinforced concrete beam

Civil Engineering: RC buildings, civilengineer, reinforced concrete beam, strenght

Civil Engineering: modelling, Computer models, simulation

Computer models, simulation : Hi Joseph, Modelling is an mathematical analytical method that results in a computer generated representation of a structure using finite element methods with correct geometry and sizes of members (columns, beams) and plates (walls and slabs). This simulated...

Civil Engineering: Question from the TV show CSI, britle, fracture

britle, fracture, bridge: Dear Jon I list some probable causes : 1- Local or total corrosion of steel due to environmental effects. 2- Laminarity of steel due to defects in steel: In this situation steel is prone to fail under loading along specific layers. 3- Exploding of...

Civil Engineering: Raft Foundation, Raft applied pressure higher than bearing capacity

Raft applied pressure higher than bearing capacity: Hi Mohammad, If you cannot reduce the loading, then the only 2 options are to either make the raft plan area bigger, or place the raft deeper, so that the B.C. of the soil is increased by an amount equal to the weight of extra soil excavated. If you can...

Civil Engineering: RC buildings, Pad foundations high-rise

Pad foundations high-rise: Hi Keesh, A rule of thumb is to have a joint every 50m approximately, but if the joint causes other problems then you can design for additional thermal stresses and do even 100m without joints. Yes, so long as the applied pressure under the pads is within...

Civil Engineering: scientist, vacation employment, civil engg

vacation employment, civil engg, b tech: Hello Devendra, You might want to check out if NASA has any work placement or internships which you could be a part of or even summer vacation employment. I would highly recommend it during your studies as it gives you a wider perspective and opens up...

Civil Engineering: Seismic Effect on Foundation, Overstress on foundation seismic

Overstress on foundation seismic: Hi Waseem, See this article, which explains the intent: http://www.gostructural.com/magazine-article-gostructural.com-october-2006-section_1801.2.1_foundation_design_for_seismic_overturning-4767.html In the past what I have done for foundation design...

Civil Engineering: Solved Examples, etabs, sap

etabs, sap, stiffness: Dear Mohammad Usually the connection between systems are concerned to be rigid diaphragms. In sap2000 and etabs we make use of this option to control load distribution between systems, which is indeed proportional to system stiffness. Then tell me...

Civil Engineering: Strength of materials, strain

strain: Dear varun You must look for properties in material which may change with the state of strain or stress. I dont know any method other than you have found yourself but I can say that no absolute state of strain may be measured but you may only trace the...

Civil Engineering: structural design, weight of roof, flush or hidden beams

weight of roof, flush or hidden beams: Hi Saif, 1. Calculate the total surface area of the steel sheets and multiply by its unit weoght/m2, or by its thickness times 75 kN/m3. For the timber work out the total lengths times the cross-sectional area to get volume in m3 and multiply by 7 kN/m3...

Civil Engineering: thesis topic selection at masters level, Lecturing in Building Engineering

Lecturing in Building Engineering: Hi Taseer, If your university has a department or course in Buiding Engineering (like mine did at Bath University, UK), then that is the right one for you. Otherwise you can join the civil engineering department but restricting yourself to buildings, materials,...

Civil Engineering: Topic, bridge

bridge: Dear Asad I mean due to large distamce between piers time histories from one pier to another may differ. Then you dont have a sigle time history acting same time on all piers. You may have a typical time historiy acting on piers with delays. Regards...

Civil Engineering: Tunnel design, tunnel

tunnel: Dear Aizaz please take a look at this link: http://www.google.com/url?sa=t&rct=j&q=tunnel+shape+calculation&source=web&cd=6&cad=rja&ved=0CF8QFjAF&url=http%3A%2F%2Fuww.ita-aites.org%2Ffileadmin%2Ffilemounts%2Fgeneral%2Fpdf%2FItaAssociation%2FProductAndPublication%2FWorkingGroupsPublication%2FWG7%2FTust_Vol_3_3_237-249.pdf&ei=Os7SUNjqKojU0QWbvoCACA&usg=AFQjCNHlr2muDhTCmeOE_j_8h8lRam6w-Q&bvm=bv.1355534169,d.d2k...

Civil Engineering: weir design, gravity wall, soil pressure

gravity wall, soil pressure, soil investigation: Hi Priyantha, It is difficult for me to give proper advice as there could be various local factors that influence the design. However, in principle: 1. Depending on how compressible the river bed is, yes you can incorporate soil springs. If it is fairly...

Civil Engineering: Wind Tunnel Analysis, wind tunnel tests, cfd software

wind tunnel tests, cfd software, wind loading: Hi Mohammad, A wind tunnel is a building made like a huge tube (around 2-3m diameter) which has a large fan at one end to create wind flow at varying velocities. In the middle of that one can place models of buildings or other items (planes, cars, etc)...

Civil Engineering: about building engineering, Nuclear Reactor

Nuclear Reactor: Dear Anna Nuclear reactor is a small part of a nuclear power plant. Several buildings exists in a nuclear power plant each with its specific function. According to type of nuclear power plant , other structure than Nuclear reactor could be polluted with...

Civil Engineering: Civil Engineering thesis topic, project management

project management: Dear Joanne There is a lot of subject to pursue in this topic: 1- Probabilistic approach to construction management, project control 2- Bayesian inference approach to estimate different indexes of projects control 3- project management topics like:...

Civil Engineering: Concrete Methodology from height, concreting

concreting: Dear Shakti You must work on your concrete admixture to reach to a fine grained concrete. In addition you must be careful about falling concrete which is not good for your concrete integrity. Then you must provide your concreting system with efficient tube...

Civil Engineering: Cutting of RCC beam rebars thru anchor bolts pockets, anchor bolts, external reinforcement

anchor bolts, external reinforcement, vertical pumps: Dear Zain The only way to resolve this problem is to analysis your slab and beam with the actual loading on them. I am not very anxious about 3 cut bars in each direction. But if the pump is relatively heavy and has significant vibration it will affect...

Civil Engineering: Deck Slab - Steel, Profiled sheet decking slabs composite

Profiled sheet decking slabs composite: Hi Muzaffer, This depends on whether you use proprietary profiled sheet decking (such as Comflor- see http://www.steeldeckinguk.com/comflor80.html) or just normal metal decking without any bonding ribs (such as roofing sheets). If it is the latter, then...

Civil Engineering: design live loads, Design life over-design

Design life over-design: Hi Mathew, Not necessarily as the life of a structure is dependant on many factors such as quality of construction, materials used, the exposure conditions, etc. Overloading is just one of the factors, but not the main one as there are factors of safety...

Civil Engineering: Dynamic analysis, isolator, macro module modelling

isolator, macro module modelling: Dear JulieSreejith There are 2 kinds of modelling concerning the information in access and complexity of your system. 1- micro module modelling: In this model you make your bases on the basic properties of materials and the behavior of your whole...

Civil Engineering: Eccentric loading on pile cap., pile

pile: Dear Jang It depends on the moment applied. The moment will apply greater axial loads on some piles and smaller axial loads on some others in comparison to net axial loading. Then you have to calculate carefully your moments and axial loads due to them....

Civil Engineering: ETABS, Etabs, finite element

Etabs, finite element: Dear PRIYANTHA 1- this is not the only criteria but when a structure has long period (say more than 0.8 or so ) it is likely that the contribution of higher modes gets important and then the equivalent static method which is based on first mode of vibration...

Civil Engineering: ETABS, etabs

etabs: Dear Priyantha Design of shear wall , deck and slab have their own discipline because a deck and slab are loaded and behave out of their plane but a shear wall is loaded and behave in its plane. Please don t hesitate to let me know about any question...

Civil Engineering: Civil Engineering thesis topic, civil engineering

Civil Engineering: Civil Engineering thesis topic, civil engineering

Civil Engineering: Dynamic analysis, buffalo state university, teflon bearings

Civil Engineering: Dynamic analysis, buffalo state university, teflon bearings, rubber bearings

Civil Engineering: Eccentric loading on pile cap.

Civil Engineering: Eccentric loading on pile cap.

Civil Engineering: frame-shear wall design, shear wall

shear wall: Dear Ananda For hand calculation you don t need to model your shear wall with your frame. You will calculate the portion of lateral loading ( wind or earthquake) on shear wall according to its relative stiffness # shear wall / frame ). Can you imagine...

Civil Engineering: lateral load, strip footing

strip footing: Dear RS 1- It means that your frame has to be able to resist about 20% of earthquake loading alone without any help from shear walls . You need 2 models and you cant do both analyses using a single computer model (file). 2- Yes you apply seismic loads...

Civil Engineering: about mix design, concrete admixture

concrete admixture: Dear Mahesh Concrete admixture design is an art which should be performed using several parameters. 1- Properties of sand and gravel used in admixture 2- cement properties which can be assumed to be standard 3- water contain 4- additives No one...

Civil Engineering: Necessary space to be left between two high rise towers, drift

drift: Dear Mahesh The 15 meters distance between towers is a restriction oriented toward day light and wind around towers. I suggest you to check a 0.01 to 0.015 height of the shorter tower as a very approximate criteria for your purpose. separation= 0.01-0.015*...

Civil Engineering: portal frame, crane, industrial buildings

crane, industrial buildings: Dear Sumon 1- design assuming fixed base will be more economical considering the frame but it needs more complicated foundation. pin based design will give you economical foundation but you must provide appropriate detail to for releasing moment in base...

Civil Engineering: raft foundation, reaction

reaction: Dear priyantha When the joint is fixed no deformation will occur there. In the case of spring the deformation is allowed depending on your spring stiffness. The value of spring stiffness come from Reaction Coefficient of soil provided by geotechnical...

Civil Engineering: RC DESIGN, reinforcement

reinforcement: Dear priyantha There is No technical limit to increase the reinforcement. In non seismic area it will be less critical too. But I prefer to use same reinforcement in lower story . I mean I prefer to have a conservative design to use the reinforcement of...

Civil Engineering: Regarding construction management, project management

project management: Dear Rishav Project management is potentially a very rewarding career. It also has a lot and a lot to study ,to understand ,to experience and to teach. It is an ocean of knowledge if you are looking for. I hope you to be lucky. Regards Babak E Hakim...

Civil Engineering: Reinforcement joint details between columns and beams., joint

joint: Dear Thair Joint detail in seismic regions shall to be considered different as non seismic regions. I guess you might be in high seismicity region in Iraq. It is Recommended to follow this way considering the big Rule of CONTINUITY OF REINFORCEMENT: ...

Civil Engineering: Stresses on Reactor Components, Reactor, stress

Reactor, stress, safety: Dear Hafeez No real difference between stress in a reactor and a simple structure. The difference exists between the probability of failure we look for in these two categories. Then the margin of safety is different. You cant accept failure in a reactor...

Civil Engineering: structural system of cantilever structures, architect, cantilever

architect, cantilever: Dear Avgi Please look at the image I sent you and let me know wether it is satisfying or not. If you would insert columns on free end of cantilever you would have more efficient building but I guess architects must do they work to provide us with beauty...

Civil Engineering: Tank foundation on piles, steel water tank, ring beam

steel water tank, ring beam, pile caps: Hi Barek, I am assuming that the base of the tank is self-supporting, i.e. all the 1200 tonnes will be distributed equally around the perimeter, which is 3.142x12= 37.7m long. So, if you have 22 piles (which should be placed directly below the tank walls),...

Civil Engineering: undergroundwatertank desin, water tank

water tank: Dear raviarjun The thickness of your water tank depends concrete strength and also reinforcement class. The situation of water tank wether being under ground or not is important. Then you must be specific to let me help you further. Regards Babak...

Civil Engineering: ACI, ACI

ACI: Dear Abdul Please have a search on Internet , there is a lot of books you can go for them. In my opinion the commentary of ACI is ok, or the code itself, or any American textbook for RC design may have points to give you. Regards Babak E Hakim...

Civil Engineering: alignment of column, misalignment

misalignment: Dear Abdul It depends on the extent of misalignment and the quality of it. The column should not be misaligned significantly. Sometimes a dislocation of frameworks in concreting process may show you like a misalignment of the column, while its is a bad...

Civil Engineering: Anchor Rod Design, anchor bolt

anchor bolt: Dear Muzaffer there are 3 ways to anchor a bolt: 1- use of bounding between bolt and concrete in cast in place concrete, in this case you must use at least fourteen times the diameter of bolt as its length: L= 40 D 2- Mechanical anchoring which is...

Civil Engineering: Architecture, architect, structure

architect, structure: Dear Micheal Architecture is an art to create and imagine medias for the people to give them comfort, creativity, power and peace. To realize such an imagination an architect needs to know how would her/his imaginations come true. To create an space you...

Civil Engineering: civil engg, retrofit

retrofit: Dear Abdul usually it is not possible to add columns but you can add shear walls in faces of buildings or stabilize the existing walls ,reinforcing of walls and confining with shutcreet and so on. You can also use steel bracings in some spans of your building....

Civil Engineering: civil engineering, seismic, earthquake

seismic, earthquake, intensity: Dear sreekanth Usually the severity and intensity of seismic action is modelled numerically by coefficients which are multiplied by the effective mass of the building. In higher zones the buildings must designed according to greater lateral forces (greater...

Civil Engineering: COL BARS in ETABS, design column, click design

design column, click design, waseem: Hi Waseem, Normally one would only indicate numbers and diameters of bars if you want the design to be checked. If you want ETABS to design the column, then do not indicate nos/diameters of rebar (or just define them as minimum 0.4% or 1%, depending on...

Civil Engineering: concern about a gf slab, wall footing, footing reinforcement

wall footing, footing reinforcement, concrete strength: Dear Adel I am anxious about your roof slab. you mentioned that they have delivered a 200 kg /m3 for it. Please tell me all details about the roof with false concrete strength. The reinforcement and thickness of the slab is important. Regards Babak...

Civil Engineering: Concrete strengths fcu, fck and fc, allah hafiz, concrete strengths

allah hafiz, concrete strengths, kaleem: Hi Kaleem, Fc is cylinder strength at 28 days and Fcu is cube strength at 28 days. The relationship between the two is not linear, and you can find that by browsing my past answers. Fck is not a terminoligy I have used before but I gather it is the same...

Civil Engineering: Consultancy work from home., job

job: Dear Mohamed Salaam In my country there is no such an opportunity but I guess it might be possible in Persian gulf countries like Dubai, Qatar or so. You can try it through www.naukrigulf.com. Regards and good luck Babak Esmailzadeh Hakimi ...

Civil Engineering: design of building, teacher, teaching

teacher, teaching: Dear Abdul Take a look on these links: http://www.civilprojectsonline.com http://www.beamchek.com/AcrobatFiles/IntroLoadPath.pdf http://www.metalwebnews.org/ftp I don t believe that you can find a book to get professional. The only way is to do...

Civil Engineering: design of a weir, river, wall

river, wall: Dear Priyantha 1- I suggest you to design and construct a drainage beside the wall along the height of the wall with gravel. 2- Wave loading depend on height and velocity of waves which are based on statistical data from the river of your area. I...

Civil Engineering: dewatering, mat foundation, pile

mat foundation, pile: Dear raviarjun I suggest you to use mat foundation. Pile cant be used before you know the depth and height of poor sand. Can you give me an idea of the strength of the soil profile there? If you have a 1 kg / cm2 of allowable stress you can easily use...

Civil Engineering: ETABS, drift

drift: Dear priyantha 1- Choose a perspective view and then do what you did before. With a right click on a node you can see the displacements. May be your units are not ok . Check your units and your loadings. Sure this feature works . 2- Drift is relative...

Civil Engineering: ETABS, spandrel, pier

spandrel, pier: Dear priyantha when analyzing the shear wall, a shear wall is nothing than set of area members. But their design is a bit different and you must assign some other labels like spandrel and pier to area members. Spandrels are shear wall elements transferring...

Civil Engineering: ETABS points within mesh, slab, mesh

slab, mesh, arrow: Hi Priyantha, I beleive those cross-points are from internal automatic meshing by the software and these are not points that can be selected for supports or for applying loads. If you want to have a finer mesh for loading or supports, you will need...

Civil Engineering: ETABS - Rigid Diaphragm Usage, diaphragm

diaphragm: Dear Nourelhouda When I talk about diaphragm I mean horizontal diaphragm, ok? A rigid diaphragm have an effect of distribution of lateral loads to structural elements relative to their stiffness just in each story. Each story perform separately and you...

Civil Engineering: ETABS Supports, ETABS supports springs

ETABS supports springs: Hi Priyantha, 1. To select points, you just need to view the points and select either by mouse-window selection, or mouse left-click. 2. Support is for fixed, pinned, rollers, etc; spring allows you to use soil modulus; displacement allows you to pre-input...

Civil Engineering: ETABS Supports

Civil Engineering: ETABS Supports

Civil Engineering: Guide me, foundation

foundation: Dear Ahad Sorry for my late answer. You must have such an excavation to get to a foundation depth suitable for your neighbors too. Work on your foundation depth. May I know the type of your foundation soil and its strength? Regards Babak E Hakim...

Civil Engineering: improper alignment of colulmn, exact reference, question sir

exact reference, question sir, misalignment: Dear Abdul Generally a tolerance of up to 5% is accepted all engineering activities. to be cautious i suggest you 3%. Sag in beams may be from 2 source: - Deflection of the beam which may be : 1- predicted by analysis 2- unpredicted and unwanted: This...

Civil Engineering: information, Quality Control

Quality Control: Dear Abdul QC (Quality Control) is a very extensive discipline in construction. I suggest you to follow 2 main courses: 1- Material QC 2- Staff QC 2- Process QC For each of the disciplines you must make guidelines and forms according to your very...

Civil Engineering: ob opportunities for Diploma holders, job

job: Dear SURAJ Laghe I guess there are opportunities in Persian Gulf countries and also in India but I cant give you exact references. you can try www.naukrigulf.com to prepare a good resume which will be sent to Arabian and Indian companies. Regards Babak...

Civil Engineering: Peripheral Beam Design in Flat Slabs, detailing, structural

detailing, structural: Dear Pramod Reddy Sorry for my late answer. Detailing is rather an art, then something to help you is not a single book but a lot of details you must see either on the net or drawings or in the architectural handbook. I suggest you to have look in architectural...

Civil Engineering: point load on slab, punching

punching: Dear Sumon You don t have a theoric point load for sure. Then you must check the strength of the slab for punching action. I don t belive that a 1 ton loading would be hard to resist . No need to provide beam but check for punching effect. Please let me...

Civil Engineering: raft foundations-etabs, subgrade modulus

subgrade modulus: Dear priyantha 1- Right 2- It is easy by assigning higher stiffness or thickness in bands where you need. 3- Its some how similar to meshing of slabs and walls (i.e. spring distance being equal to thickness of foundation) 4- No you have replaced your...

Civil Engineering: Story forces, Diaphragm forces and story stiffness, stiffness

stiffness: Dear KHURRAM 1- Story lateral loads and diaphragm loads are the same. The diaphragm distributes story loadings among structural elements then diaphragm loading must be equal to story loading. 2- Fix the lower story , apply a unit load on the diaphragm...

Civil Engineering: supports on beam, hinge, pinned

hinge, pinned, simple support: Dear Abdul you have 3 types of simple support. 1- Industrial type pin connection which is applied essentially in steel bridges. 2- conventional hinge support like the bearing support made of angle, which let the beam rotate on it without producing...

Civil Engineering: Swimming Pool Construction on Building Terrace/Roof, pool

pool: Dear Prashant you should follow the following steps toward your target: 1-Look for as built drawings to check the actual situation of the building. 2-Look for the constructional drawings to check the probable actual situation of the building. 3- Make...

Civil Engineering: Swimming Pool Construction on Building Terrace/Roof, Terrace ground swimming pool

Terrace ground swimming pool: Hi Prashant, 1. On the ground, you dig a hole, place blinding for the floor, place rebar and formwork and cast the slab. Then place the rebar and formwork for the walls and cast the walls. 2. For terrace, as above, but you need formwork for the slab...

Civil Engineering: transportation, Retaining Wall culverts analysis & design

Retaining Wall culverts analysis & design: Hi Kireeti, I am not an expert on transportation and I do not know what a ghat road is. However, see links below for design of retaining walls and culverts: http://www.cantileverwall.com/download-8.html http://www.structsource.com/drainage/types/culvert.htm...

Civil Engineering: Uunderground water tank, underground water tank, kind advice

underground water tank, kind advice, tank size: Hi Ravi, Structurally you do not need any partition; however for operational reasons you may need it- depends on its purpose. For example, if you need to clean the tank, with a partition you could clean one half at a time without interupting supply...

Civil Engineering: 2D Frame -to 3D FRAME, model, structure

model, structure: Dear Sirisha A member inside a structure has connections with other members. These connections force the members connected to , to rotate. Then the connections inside a structure are not perfect. For a single member modeled as connected to its support ideally,...

Civil Engineering: Bridges, cable stayed bridge, vertical support

cable stayed bridge, vertical support, tall structure: Dear William I recognize both Pier and Tower names for the structure supporting the cables, but Tower a bit more popular than Pier . Pier is a more general name to describe the vertical support of ordinary bridges. A vertically extended Pier...

Civil Engineering: Building Construction Business Rules, urban laws, regulation

urban laws, regulation, building: Dear Prashant S Akerkar The problem of construction is not only to decide about the number of stories to have more benefits. 1- Urban regulations do not let us construct any building with any number of stories. When you construct a high rise building...

Civil Engineering: concrete quantity, concrete quantity, shop drawing

concrete quantity, shop drawing, hakimi: Dear Anasari You may have a set of drawings. If not you have to provide a set of sketch of your structure along with rough estimate of beams and columns and slabs size and thickness. Then you can have estimation of concrete consuming calculating the volume...

Civil Engineering: Concreting on rainy days., concreting

concreting: Dear Raj I think it is better to use some cover, to guarantee the concreting being complete, if not you will be forced to stop concreting and continue after a while. The bounding between can be increased using chemical agents or simply cement grout. But...

Civil Engineering: earthquake, base isolators, visual geometry

base isolators, visual geometry, earthquake loading: Dear priyantha 1- Conventional seismic design is based on sizing of structural elements according to a standard loading. Then base isolation is one of the methods and the only one to protect. A base isolation provision reduce the effect of a strong earthquake...

Civil Engineering: earthquake, earthquake intensity, earthquake in indonesia

earthquake intensity, earthquake in indonesia, earthquake loads: Dear Priyantha 1- It is very common practice to design buildings in earthquake prone countries without base isolation. Then it is not wrong at all to have conventional seismic designed buildings. 2- The people feeling is not a proper criteria to assess...

Civil Engineering: ETABS, Bayesian

Bayesian: Dear Priyantha 1- I think the friction effect may have effect in this problem. You don t have a smooth surface of bedrock there. Anyway I accept your point about socketing. I haven t yet seen an evaluation method for such a situation. 2- As you said...