tribhuvan university institute of engineering central
TRANSCRIPT
Tribhuvan University
Institute of Engineering
Central Campus, Pulchowk
DEPARTMENT OF CIVIL ENGINEERING
Earthquake Resistant Analysis and Design of Multistoried Building Preliminary Design Report
Submitted By: Submitted To:Aayush Phuyal (070-BCE-003) Er. Sujan Tripathi Abhash Acharya (070-BCE-004) Group SupervisorAjar Lal Shrestha (070-BCE-009) Alisha Siwakoti (070-BCE-011)
Anupam Bhattarai (070-BCE-022) Avinab Malla (070-BCE-029)
BuildingConfigurationBuildingshavingirregularconfigurationsuffermuchmoredamageduringearthquakesthanbuildingswithregularconfiguration.So,theprovidedarchitecturaldrawingswerealteredinordertoachievearegularconfigurationbyavoidingthefollowingirregularities,asstatedinIS1893:2002Tables4&5.
PlanIrregularities
1. TorsionIrregularity2. Re‐entrantCorners3. DiaphragmDiscontinuity4. Out‐of‐planeoffsets5. Non‐ParallelSystems
VerticalIrregularities
1. StiffnessIrregularity–SoftStorey2. StiffnessIrregularity–ExtremeSoftStorey3. MassIrregularity4. Verticalgeometricirregularity5. In‐planeDiscontinuityinverticalelementsresistinglateralforce6. Discontinuityincapacity‐WeakStorey
GravityLoadAssessmentforPreliminaryDesignThepreliminarysizingofstructuralelementswascarriedoutbasedondeflectioncontrolcriteriaandapproximateloadsobtainedusingthetributaryareamethod.
ThegravityloadsonthestructuralelementsaretakenasperIS875PartI(deadloads)andIS875PartII(imposedloads).
Theunitweightsofmaterialstakenforthecalculationofdeadloadofthestructureareasfollows.
S.N. MaterialUsed UnitWeight TypeofMember1. CementConcreteforRCC 25kN/m3 Beams,Columns,Slabs.2. CommonBurntClayBricks 20kN/m3 Infill&PartitionWalls3. Screedonfloor25mm 20kN/m3 Allflooringspaces4. Finishinginstep30mm 20kN/m3 Allflooringspaces5. Floorfinishing 1kN/m2 LoadonSlabTheimposedloadonthefloorsandroofhasbeentakenasfollows
S.N.LiveLoadsonSpecifiedSpaces IntensityofLoad MemberLoaded
1. Allroomsandkitchens 2.0kN/m2 Liveloadsfrombuildingareactedonfloorslabs,roofslabsandstaircaseslab.
2. Toiletandbathrooms 2kN/m2
3. Corridors, passages, staircasesincludingtireescapesandstoreRooms
3kN/m2
PreliminarySizingofSlabThedepthofslabisobtainedfromdeflectioncontrolcriteria.L/d=32forcontinuoustwo‐wayslabOr,d=L/30=4114.8/32=128.58mmWhere,L=LongestShorterspanofallslabs=4114.8mmAdoptd=125mmandD=150mmwithclearcoverof25mm.
LoadIntensityonSlabSelf‐weight=25*0.150=3.75kN/m2Imposedliveload=2kN/m2
Floorfinish=0.3kN/m2
Totalloadintensity=6.05kN/m2
PreliminarySizingofBeamLengthoflongestbeam=16’‐6”=5029.2mm
DeflectionControlFordeflectioncontrol,asperIS456:2000,Clause23.2.1,
L/d≤αβγδλ
Where,
L=lengthofbeam=5029.2mm
d=Effectivedepthofthebeam
α=26forcontinuousbeams
β=1forspansbelow10m
γ=0.8(assumingthetensilesteelpercentageas1.2%)
δ=1fornocompressionsteel
λ=1fornoflangedbeams
Substituting,weget
d=242mm
Adoptd=300mmandD=325mmwithclearcover25mm.Adoptb=230mm
FlexuralloadsonbeamTheflexuralloadonthebeamiscalculatedbyuniformlydistributingtheloadsfromtheeffectiveslabareaandwallsthroughoutthebeam.Thebeamisanalyzedasasimplysupportedbeam.
Self‐weightofbeam=25×0.325×0.230=1.869kN/m
Weightofwall,assuming30%openings=20×0.23×3.2×0.7=10.304kN/m
LoadsfromSlabs
EffectiveLoadingAreaofSlabsonBeam=131.7959ft2=12.25m2
Distributedload=12.25×6.05/5.0292=14.73kN/m
TotalDistributedLoad=26.903kN/m
DesignMid‐SpanMoment=1.5wL2/8=1.5×26.903×5.02922/8=127.58kNm
Q=0.36×fck×(Xu,lim/d)(1‐0.416(Xu,lim/d))=3.3478
127.58 103.3478 230
407
Adoptb=300mm,D=500mm
Tributaryareaforbeam2BC
PreliminarySizingofColumnsThecolumnsizeisfirstassumedtobe500mm×500mmfordeadloadcalculations.
Column2BSlabarea=185.6406ft2=17.26m2
Loadofslab=6.05×17.26=104.423kN
LoadofWalls(Assuming30%openings)
=0.7×20×0.23×3.2×(7’1.5”+8’3”+6’6”+5’4.5”)=0.7×20×0.23×3.2×8.3058=85.58kN
LoadofBeam=25×0.3×(0.5‐0.15)×8.3058=21.80kN
DeadLoadofColumns=25×0.500×0.500×3.2=20kN
Deadloadofbasementcolumn=25×0.500×0.500×3.05=19.06
Totalload=11×104.42+11×21.8+10×85.58+10×20+19.06=2463.28kN
FactoredLoad=1.5×2463.28=3694.92kN
Taking2%steel,M25ConcreteandFe500Steel,
Pu=0.4fckAc+0.67fyAs
Or,3694.92×1000=0.4×25×(1‐0.02)A+0.67×500×0.02A
Or,A=223935mm2
Takingasquarecolumn,
B=D=473.22mm
ColumnE3SlabArea=204.3788ft2=19.00m2
Loadofslab=6.05×19.00=114.95kN×11
LoadofWalls(Assuming30%openings)
=0.7×20×0.23×3.2×(8’3”+7’10.5”+5’4.5”+7’1.5”)=0.7×20×0.23×3.2×8.7249=89.90kN×10
LoadofBeam=25×0.3×(0.5‐0.15)×8.7249=22.90kN×11
DeadLoadofColumns=25×0.500×0.500×3.2=20kN×11
Deadloadofbasementcolumn=25×0.500×0.500×3.05=19.06kN×1
LoadfromStaircasecover
Slab=25×6.05×64.9692ft2=150.97kN×1
Walls=20×0.23×3.2×(8’3”+7’10.5”)=72.35kN×1
Beam=25×0.3×(0.5‐0.15)×4.915=12.90kN×1
Totalload=11×114.95+10×89.90+11×22.90+11×20+1×19.06+150.97+72.35+12.90=2890.63kN
FactoredLoad=1.5×4335.945=4335.945kN
Taking2%steel,M25ConcreteandFe500Steel,
Pu=0.4fckAc+0.67fyAs
Or,4335.945×1000=0.4×25×(1‐0.015)A+0.67×500×0.015A
Or,A=262785mm2
Takingasquarecolumn,
B=D=512.63mm2
Adoptcolumnsizeof560mm×560mm
TributaryAreaforColumnB2
TributaryAreaforColumnE3