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