Staircase Design 1
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DESIGN OF STAIR CASE 1 Basic Data: width of the waist slab = 1.5 m Rise of the stai [ R ] = 150 mm Tread of the stair [ T ] = 300 mm = 335 mm Grade of the concrete = M 25 Grade of the steel = Fe 415 Live load on the slab = 5 Depth of the waist slab assumed [ D ] = 100 mm Clear cover to the Reinforcement Cc = 32 mm Effective depth of the waist slab [ de ] = 62 mm Stair Beam: Breadth of the beam = 250 mm Over all depth of the beam = 1300 mm = 1245 mm = 12.5 = 12.940 > 2 loads on steps: = 25 Self weight of the slab = 2.8 k N/m Self weight of the step = 0.56 k N/m Finishes @ 0.8k N/sq m = 0.8 k N/m Live loads on the slab per m width = 5 k N/m Dead load of the beam = 16.25 k N/m Total load [w ] = 25.41 k N/m Factored Load = w*1.5 = 25.41 k N/m Total Load on the edge beam = 25.41 k N/m No of edge beam (n ) = 2 Nos Total load on one edge beam = 12.705 k N/m 3 Loads on Landings: Self weight of the slab = 2.5 " finishes = 0.8 " Live loads = 4.5 " Total load [w ] = 7.8 Factored Load = w*1.5 = 11.7 " length of the landing slab = 1.5 m length of the waist slab = 9m Thickness of the wall = 300 mm 12.705 steps landing 0 A 16 0 B 16.11 102.3 102.4 . Sqrt (R 2 +T 2 ) k N/m 2 Effective depth of the beam d effect ermissible L /deffe ratio for simply supported beam Actual Leff / d ratio Density of the concrete (gc ) k N/m 3 k N/m 2 RA = RB =
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staircase design
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es stair op-2DESIGN OF STAIR CASE1Basic Data:width of the waist slab=1.5mRise of the stai [ R ]=150mmTread of the stair [ T ]=300mm. Sqrt (R2+T2)=335mmGrade of the concrete=M25Grade of the steel=Fe415Live load on the slab=5k N/m2Depth of the waist slab assumed [ D ]=100mmClear cover to the Reinforcement Cc=32mmEffective depth of the waist slab [ de ]=62mmStair Beam:Breadth of the beam=250mmOver all depth of the beam=1300mmEffective depth of the beam d effect=1245mmPermissible L /deffe ratio for simply supported beam=12.5Actual Leff / d ratio=12.940>2loads on steps:Density of the concrete (gc )=25k N/m3Self weight of the slab=2.8k N/mSelf weight of the step=0.56k N/mFinishes @ 0.8k N/sq m=0.8k N/mLive loads on the slab per m width=5k N/mDead load of the beam=16.25k N/mTotal load [w ]=25.41k N/mFactored Load = w*1.5=25.41k N/mTotal Load on the edge beam=25.41k N/mNo of edge beam (n )=2NosTotal load on one edge beam=12.705k N/m3Loads on Landings:Self weight of the slab=2.5"finishes=0.8"Live loads=4.5"Total load [w ]=7.8k N/m2Factored Load = w*1.5=11.7"length of the landing slab=1.5mlength of the waist slab=9mThickness of the wall=300mm12.705stepslanding0A16.110B16.11RA =102.3RB =102.4D1300mmd1245mmSelf weight of the beam = gc*B*D=8.125k N/mMD=263.59k N-mMax Moment at the Centre of the span due to stair case arrangement=411.86k N-mTotal Bending Moment=675.44k N-mEffective Depth required d eff=884.9428854083mmMu/B*d2=1.743N/mm2Percentage of steel required pt=0.530%Dia of bar used [f ]=32mmArea of steel required [ Ast ]=1649.625mm2No of bars required=3Nos~3NosDesign of shear:Factored Support reaction=153.6k NNominal Shear strength of the concrete tv = Vu / B*d=0.49N/mm2Design Shear strength of the concrete tc=0.36N/mm2Shear to be Designed=42k NVus / d=0.33k N/cmSpacing of Shear R/F Required [ s ]=250.00DESIGN SHEAR R/FDia of shear R/F to be used=8mmArea of two legged stirrups Asv=100.53mm2Area of shear R/FMini Shear R/F = [ Asv x 0.87*fy ] / 0.4* b=362.9670488252mmSpacing of Shear R/F provided [ s ]=150.00mmWaist slab Designast = 0.12* B*D=111.6mm2Dia of distribution steel [ f 1 ]=8mmSpacing of reinforcement required=450.41mmSpacing of bar provided s=200mmProvide main steel bar of 8mm dia at 200mm c/cCheck for Short term Deflection:616Escalator stair edge beam14.95Length of the beam:=16.11m5xw x l 4Formula for max short term deflection:=384* E * I effeShort term modulas of elasticity of the concrete [Ec ] = 5000xf ckEc =5000xf ck=2.50E+04N/mm2Modulas of Elasticity of the steel [ Es ]=2.00E+05N/mm2** Gross Sectional Properties of the section :Breadth of the Beam [ B ]=250Depth of the beam [ D ]=1300Gross Moment of Inertia of the section : Igr = B* D3/12=45770833333.3333mm4Cracking Moment [Mcr] = fcr * Igr / ytModulas of rupture of the concrete fcr = 0.7 * fck=3.5N/mm2Centroidal axis of the gross section [ yt ] = D/2=650mmMcr ==fcrxIgry t=3.5*4.58E+10650Mcr=2.5E+08N-mm=246.4583333333k N-mMcr = 0.7 * Mcr=172.5208333333k N-mTotal Bending Moment due to Live and Dead load=675.44k N-m=Mcr
