Combined FootingDesign of Combined Footing6mtrsFINAL DETAILSData:fc'=21Mpa1.5mtrsL =6mtrsfy=400MpaSoil Pressure qa=126.35KpaColumnDLLLColumn Size l x wDist from C1 face to edge:4.5mtrs16001111.9226006001.5mtrs21141.466265.02600600Distance Bet. Col. =2.4mtrsDet. the size of the footingX=1.0824646422mtrsB =4.5mtrsPwT=D+LR=3118.408Pw1=600+1111.922=1711.922kNPw2=1141.466+265.02=1406.486kNTotal=3118.408kNAreq =BL =PwT=3118.408=24.6807123071sq.mqa126.35Solving for X by taking moment @ C1Wu =744.6520483078kN/mRX =Pw2 * Dist. Bet. Col.41.5m0.9m3118.408* X =1406.486*2.4Solving for Shear and Moment DiagramX =1.08246464221For Shear2.1m2.4m1.5m516mm bars @500mmshort dir barsL=X +C1 L + Edge Dist.xV-DiagFor pt. 1 =Wu * (C1/2+Edge dist.)223=1340.373686954kN16pcs25mm dia TOP BARSspaced @300mm OCL =5.7649292844say6mtrsFor pt. 2 =Pt.1 - Pu1B =Areq=4.2811821428mtrs say4.5mtrs5=-1158.701513046kNt =555mmL2For pt. 4 =Pt.2 + Wu * Dist. Bet. Col.Solving for Wu=628.4634028926kNPu1 =1.2 DL + 1.2 LL =2499.0752kNFor pt.5 =Pt.4 - Pu216pcs25mm dia BOT BARS spaced @320mm OCPu2 =1.2 DL + 1.2 LL =1793.7912kN68=-1165.3277971074kN1.305mtrs2.5425mtrs1.305mtrs0.8475Total =4292.8664kNM-DiagFor Momentqu =4292.8664=173.9360820136Solve dist. Bet. Pt. 2 & 324.6807123071x =(Dist. Bet. Col)*Pt.2/(Pt.4 + Pt. 2)Wu =Total Pu=744.6520483078kN/m=1.5560307874mtrs216mm bars @500mmshort dir barsL7For Pt.6 =0.5*Pt.1*(C1/2+Edge dist.)Determining dC1/2d=1206.3363182586kN-m925mm bars @150mmshort dir barsOne Way Shear (Wide Beam Shear)For Pt. 7 =Pt.6-(.5*Pt.2*x)for Col. 1Vu=VcFrom V-Diag=304.8487044219kN-m616mm bars @500mmshort dir barsnote:For Pt. 8 =Pt.7 +(.5*Pt.4*(Dist.bet.Col. - x ))Vc =0.17(fc')bwd570.0505860744kN-m1325mm bars @100mmshort dir bars =0.75VuVu =705.717-335.2211((C1/2)+d)therefore:Vc =2629.2528049809d-1158.701513046Soln for VuVu =711910.284061377-744.6520483078dCL of C1Vu =1158.701513046-446.7912289847-0.7446520483dd =211.004848986mm=711.9102840614-0.7446520483dfor Col. 2Vu=Vcnote:628.4634028926Vc =0.17(fc')bwd =0.75Vu =836.3001 - 335.2211((C2/2)+d)Vutherefore:From V-DiagVc =2629.2528049809dVu =405067.788400263-600dVu =628.4634028926-223.3956144923-0.6dd =125.4370013322mm=405.0677884003-0.6ddC2/2Two Way Shear (Punching Shear)for Col. 1Is Edge of Footing @ Face of Column 1?noVp Vcnote:Vp =Pu1 - PsoilPsoil =qu((C1+d)/1000)^2eq.1Vc =1/6(1+(2/)(fc')bod;bo=(2400+4d)bo =(600+d)+2(600+d/2)=(1800+2d)eq.2Vc =1/12((sd/bo)+2)(fc')bodbo =(4)(600+d)=(2400+4d)eq.3Vc =1/3(fc')bodtherefore:Vp =2499.0752-173.9360820136*(0.36+0.0012d+d^2/1000000)Soln:Vp =2499.0752-173.9360820136*(0.36+0.0009d+d^2/2000000orVp =2499.0752-173.9360820136*(0.36+0.0012d+d^2/1000000Vp =2436458.21047509-208.7232984164d-0.173936082d^2eq.1Vc =4124.3181254603d+6.8738635424d^2note: =1Vc =5499.090833947d+9.1651513899d^2eq.2Vc =1374.7727084868d+13.7477270849d^2note: s=40Vc =1833.0302779823d+18.3303027798d^2eq.3Vc =2749.5454169735d+4.582575695d^2Vc =3666.0605559647d+6.1101009266d^2by QEQEeq.1d =356.0733062793mmABCB^2-4AC+-therefore useeq.2d =365.3207101292mmeq.17.04779962444333.0414238766-2436458.2104750987461925.0241033356.0733062793-970.8809987179356.0733062793eq.3d =469.374996405mmeq.213.92166316691583.4960069031-2436458.21047509138185661.709543365.3207101292-479.0640170833365.3207101292eq.34.7565117772958.2687153899-2436458.2104750955107522.4813295469.374996405-1091.3157912778469.374996405Two Way Shear (Punching Shear)for Col. 1Is Edge of Footing @ Face of Column 2?noVp Vcnote:Vp =Pu1 - PsoilPsoil =qu((C1+d)/1000)^2eq.1Vc =1/6(1+(2/)(fc')bod;bo=(2400+4d)bo =(600+d)+2(600+d/2)=(1800+2d)eq.2Vc =1/12((sd/bo)+2)(fc')bodbo =(4)(600+d)=(2400+4d)eq.3Vc =1/3(fc')bodtherefore:Vp =1793.7912-173.9360820136*(0.36+0.0012d+d^2/1000000)Soln:Vp =1793.7912-173.9360820136*(0.36+0.0009d+d^2/2000000orVp =1793.7912-173.9360820136*(0.36+0.0012d+d^2/1000000Vp =1731174.21047509-208.7232984164d-0.173936082d^2eq.1Vc =4124.3181254603d+6.8738635424d^2note: =1Vc =5499.090833947d+9.1651513899d^2eq.2Vc =1374.7727084868d+13.7477270849d^2note: s=40Vc =1833.0302779823d+18.3303027798d^2eq.3Vc =2749.5454169735d+4.582575695d^2Vc =3666.0605559647d+6.1101009266d^2by QEQEeq.1d =275.8031623786mmABCB^2-4AC+-therefore useeq.2d =300.3194590217mmeq.17.04779962444333.0414238766-1731174.2104750967579123.7827882275.8031623786-890.6108548173275.8031623786eq.3d =367.7499907679mmeq.213.92166316691583.4960069031-1731174.2104750998910756.5695806300.3194590217-414.0627659759300.3194590217eq.34.7565117772958.2687153899-1731174.2104750941688755.8728969367.7499907679-989.6907856406367.7499907679All Values of dUsing20mm dia barsd =211.004848986Therefore, use d =469.374996405mmd =125.4370013322t =469.374996405+75+20/2d =356.0733062793=554.374996405say555mmd =365.3207101292d =555-75-20/2d =469.374996405d =470mmd =275.8031623786d =300.3194590217d =367.7499907679Finding Steel AreaLongitudinal BarsTop Chord: Mu =304.8487044219kN-mMu =asfy(d-0.59Asfy); =0.9fc'bwSoln:304848704.421859=0.9(As)(400)(470-0.59*As *400)0=-304848704.421859+169200As-0.899047619As^2214500By QEAs =1784.7803856543mm^2> Asmin0.899047619169200-304848704.42185929724934007.52091784.7803856543-189983.9329280271784.7803856543Asmin=1/4(fc')(bwd)1.4(bwd)fyfy=6057.59224676987402.57402.5Therefore use As=7402.5mm^2Using25mm dia,Ab =490.8738521234NoB =15.0802491678say16pcsSpacing:4500=(75+12.5)(2) + (15)ss =288.3333333333say300mm< smaxok!smax =450mmTherefore use 16pcs 25mm dia bars sp.300mm O.C.For Bottom Bars at Col.2Mu =427537939.555831N-mmUsing same formula as above,As =2561.688614037 Asmin5.2444444444196140-1266493175.1724165039111985.83915614.2904823521-43013.86675353865614.2904823521Asmin=1/4(fc')(bwd)1.4(bwd)fyfy=1203.7853528687 Asmin1.55604395686400-211843596.8169768783511793.814672352.2444625441-57877.66819135762352.2444625441Asmin=0.0018bt=1497.6mm^2Therefore use As=2352.2444625441mm^2NoB =29.949706686say30pcsSpacing =2600-(75*2) -10/29Spacing =84.1379310345mmsay 85mmTemp and Shrinkage barsUsing16mm diaAts =0.0018bt=1497.6mm^2NoB =7.4484513367say 8pcsSpacing =2600-(75*2) -16/7Spacing =347.7142857143say348mm

Trapezoidal FootingDesign of Trapezoidal FootingAverage Width =4.0874226645Note: Both columns will be at the edge of the footing16.7584329244=4.1a+4.1bData:FINAL DETAILS2fc'=21Mpa33.5168658488=4.1a+4.1bfy=400MpaL =4.1mtrsSoil Pressure qa=126.35Kpa4.1mtrsb =33.5168658488-4.1aColumnDLLLColumn Size l x w4.11996.99177.3096006002814.935128.1946006000.3+1.5589439169=4.1(2a +b)Distance Bet. Col. =3.5mtrs3(a+b)Det. the size of the footingmtrs1.8589439169=1.3666666667*( 2a +(33.5168658488-4.1a )PwT=D+Lb =5.2302426124mtrsa =2.9446027166(4.1)Pw1=996.99+177.309=1174.299kN( a +(33.5168658488-4.1a )Pw2=814.935+128.194=943.129kN(4.1)Total=2117.428kNX=1.5589439169mtrs1.8589439169a +1.8589439169(33.5168658488-4.1a )=1.3666666667* 2a+1.3666666667*( 2a +(33.5168658488-4.1a )Areq =BL =PwT=2117.428=16.7584329244sq.mR=2117.428(4.1)(4.1)qa126.357.6216700591a +62.3059738821-7.6216700591a=11.2066666667a+45.8063833267-5.6033333333aSolving for X by taking moment @ C116.4995905553=5.6033333333aRX =Pw2 * Dist. Bet. Col.a=2.94460271662117.428* X =943.129*3.5b =33.5168658488-12.0728711381X =1.55894391694.1L = (C1/2)+S+(C2/2)Wu =53.9671861185kN/m0.3m3.5m0.3m1716mm bars @215mmshort dir barsb=5.2302426124L = 4.1mWu =509.1761505849kN/m4A = ((a+b/2))L(eq. 1)Solving for Shear and Moment Diagram18pcs25mm dia TOP BARSspaced @272mm OC4.10.3X' =(L/3)((2a+b)/(a+b))1For ShearkN509.176150584953.9671861185455.2089644664X' = ((C1/2)+X)xV-DiagFor pt. 1 =(Wu + Wu)/2*distt =524mm3.8(L/3)((2a+b)/(a+b)) = ((C1/2)+X)(eq. 2)3=147.756649224kN421.9009914567475.8681775752Solving Simultaenously Eq. 1 &2:a =2.9446027166mFor pt. 2 =Pt.1 - Pu10.337.256791506291.2239776247b =5.2302426124m5=-1332.325750776kN16pcs25mm dia BOT BARS spaced @230mm OC21.77867456152For pt. 4 =Pt.2 + Wu * Dist. Bet. Col.0.92925mtrs2.406125mtrs0.92925mtrs-0.164625Solving for Wu=-339.9144791761kNPu1 =1.2 DL + 1.2 LL =1480.0824kNFor pt.5 =Pt.4 - Pu2Pu2 =1.2 DL + 1.2 LL =1183.0324kN68=-1522.9468791761Total =2663.1148kNM-DiagFor Moment-116mm bars @215mmshort dir barsqu =2663.1148=158.9119228517Solve dist. Bet. Pt. 2 & 3mtrs16.7584329244x =(Dist. Bet. Col)*Pt.2/(Pt.4 + Pt. 2)725mm bars @126mmshort dir barsWu1 =Total Pu=509.1761505849kN/mWu2 =53.9671861185kN/m=2.7885587514kN-mL7For Pt.6 =0.5*Pt.1*(C1/2+Edge dist.)1216mm bars @215mmshort dir barsDetermining dC1/2d=22.1634973836kN-mOne Way Shear (Wide Beam Shear)For Pt. 7 =Pt.6-(.5*Pt.2*x)925mm bars @95mmshort dir barsfor Col. 1Vu=VcFrom V-Diag=-1835.4708186533kN-mnote:For Pt. 8 =Pt.7 +(.5*Pt.4*(Dist.bet.Col. - x ))Vc =0.17(fc')bwd-1956.3854093903 =0.75VuVu =705.717-335.2211((C1/2)+d)therefore:Vc =2388.1927790572d-1332.325750776Soln for VuVu =1026820.06042501-509.1761505849dCL of C1Vu =1332.325750776-305.505690351-0.5091761506dd =354.3974155034mm=1026.820060425-0.5091761506dfor Col. 2Vu=Vcnote:-339.9144791761Vc =0.17(fc')bwd =0.75Vu =836.3001 - 335.2211((C2/2)+d)Vutherefore:From V-DiagVc =2388.1927790572dVu =-492667.324351584-600dVu =-339.9144791761-152.7528451755-0.6dd =-164.8713321993mm=-492.6673243516-0.6ddC2/2Two Way Shear (Punching Shear)for Col. 1Is Edge of Footing @ Face of Column 1?yesVp Vcnote:Vp =Pu1 - PsoilPsoil =qu((C1+d/2)/1000)((C1+d)/1000)eq.1Vc =1/6(1+(2/)(fc')bod;bo=(1800+2d)bo =(600+d)+2(600+d/2)=(1800+2d)eq.2Vc =1/12((sd/bo)+2)(fc')bodbo =(4)(600+d)=(2400+4d)eq.3Vc =1/3(fc')bodtherefore:Vp =1480.0824-158.9119228517*(0.36+0.0009d+d^2/2000000)Soln:Vp =1480.0824-158.9119228517*(0.36+0.0009d+d^2/2000000orVp =1480.0824-158.9119228517*(0.36+0.0012d+d^2/1000000Vp =1422874.10777339-143.0207305665d-0.0794559614d^2eq.1Vc =3093.2385940952d+3.4369317712d^2note: =1Vc =4124.3181254603d+4.582575695d^2eq.2Vc =1031.0795313651d+9.7379733518d^2note: s=30Vc =1374.7727084868d+12.983964469d^2eq.3Vc =2062.1590627301d+2.2912878475d^2Vc =2749.5454169735d+3.0550504633d^2by QEQEeq.1d =324.9404844742mmABCB^2-4AC+-therefore useeq.2d =325.5720837574mmeq.13.51638773263236.2593246617-1422874.1077733930486882.6471371324.9404844742-1245.2767985329324.9404844742eq.3d =438.5118605297mmeq.29.81742931321174.1002619316-1422874.1077733957254375.3236989325.5720837574-445.1655358184325.5720837574eq.32.37074380892205.1797932966-1422874.1077733918355897.8481768438.5118605297-1368.6755437648438.5118605297Two Way Shear (Punching Shear)for Col. 1Is Edge of Footing @ Face of Column 2?yesVp Vcnote:Vp =Pu1 - PsoilPsoil =qu((C1+d/2)/1000)((C1+d)/1000)eq.1Vc =1/6(1+(2/)(fc')bod;bo=(1800+2d)bo =(600+d)+2(600+d/2)=(1800+2d)eq.2Vc =1/12((sd/bo)+2)(fc')bodbo =(4)(600+d)=(2400+4d)eq.3Vc =1/3(fc')bodtherefore:Vp =1183.0324-158.9119228517*(0.36+0.0009d+d^2/2000000)Soln:Vp =1183.0324-158.9119228517*(0.36+0.0009d+d^2/2000000orVp =1183.0324-158.9119228517*(0.36+0.0012d+d^2/1000000Vp =1125824.10777339-143.0207305665d-0.0794559614d^2eq.1Vc =3093.2385940952d+3.4369317712d^2note: =1Vc =4124.3181254603d+4.582575695d^2eq.2Vc =1031.0795313651d+9.7379733518d^2note: s=30Vc =1374.7727084868d+12.983964469d^2eq.3Vc =2062.1590627301d+2.2912878475d^2Vc =2749.5454169735d+3.0550504633d^2by QEQEeq.1d =269.1600847208mmABCB^2-4AC+-therefore useeq.2d =284.0807345786mmeq.13.51638773263236.2593246617-1125824.1077733926308710.7432111269.1600847208-1189.4963987795269.1600847208eq.3d =366.2925324415mmeq.29.81742931321174.1002619316-1125824.1077733945589305.8137463284.0807345786-403.6741866396284.0807345786eq.32.37074380892205.1797932966-1125824.1077733915538980.0544373366.2925324415-1296.4562156766366.2925324415All Values of dUsing20mm dia barsd =354.3974155034Therefore, use d =438.5118605297mmd =-164.8713321993t =438.5118605297+75+20/2d =324.9404844742=523.5118605297say524mmd =325.5720837574d =524-75-20/2d =438.5118605297d =439mmd =269.1600847208d =284.0807345786d =366.2925324415Finding Steel AreaLongitudinal BarsTop Chord: Mu =-1835.4708186533kN-mMu =asfy(d-0.59Asfy); =0.9fc'bwSoln:-1835470818.65326=0.9(As)(400)(439-0.59*As *400)0=1835470818.65326+158040As-0.9897959222As^2214087.4226644918By QEAs =12609.819254359mm^2> Asmin0.98979592221580401835470818.6532617709675473.3536-12609.819254359-147059.458474242-12609.819254359Asmin=1/4(fc')(bwd)1.4(bwd)fyfy=5139.29720591246280.32492399166280.3249239916Therefore use As=12609.819254359mm^2Using25mm dia,Ab =490.8738521234NoB =25.6885128426say18pcsSpacing:4087.4226644918=(75+12.5)(2) + (17)ss =230.142509676say272mm< smaxok!smax =450mmTherefore use 18pcs 25mm dia bars sp.272mm O.C.For Bottom Bars at Col.2Mu =-1467289057.04275N-mmUsing same formula as above,As =8799.3574642625>Asmin0.9897959222158040-1467289057.0427530785908501.53128799.3574642625-168468.6351928638799.3574642625Therefore,As =8799.3574642625mm^2Using25mm dia,Ab =490.8738521234NoB =17.9259038268say16pcsSpacing:4087.4226644918=(75+12.5)(2) + (15)ss =260.8281776328say230mm< smaxok!Therefore use 16pcs 25mm dia bars sp.230mm O.C.Short Direction BarsAt Column 1Is Edge of Footing @ Face of Column 1?yesB =4087.4226644918mmB' =929.25mmSpan =(B-C1)/2qu =Pu1=1480.0824=389.6761052256kN/m^2=1743.7113322459mmBB'3.79823751100.75dMu =(1/2)Wu * Span^2=550.4977268196BB'Wu =qu*B'=362.1065207809kN/mMu =asfy(d-0.59Asfy); =0.9fc'bwSoln:550497726.819563=0.9(As)(400)(414-0.59*As *400)0=-550497726.819563+149040As-4.3537414966As^221929.25By QEAs =3363.204101388mm^2> AsminABC4.3537414966149040-550497726.81956331799820788.15023363.204101388-37595.82910138793363.204101388Asmin=1/4(fc')(bwd)1.4(bwd)fyfy=1101.85025269911346.483251346.48325Therefore use As=3363.204101388mm^2Using25mm dia,Ab =490.8738521234NoB =6.8514631342say9pcsSpacing:929.25=(75+12.5)(2) + (8)ss =94.28125say95mm< smaxok!smax =450mmTherefore use 9pcs 25mm dia bars sp.95mm O.C.At Column 2Is Edge of Footing @ Face of Column 2?yesB =4087.4226644918mmB' =929.25mmSpan =(B-C1)/2qu =Pu2=1183.0324=311.4687790272kN/m^2=1743.7113322459mmBB'3.79823751100.75dMu =(1/2)Wu * Span^2=440.0137769045BB'Wu =qu*B'=289.432362911kN/mMu =asfy(d-0.59Asfy); =0.9fc'bwSoln:440013776.90451=0.9(As)(400)(414-0.59*As *400)0=-440013776.90451+149040As-4.3537414966As^221929.25By QEAs =2733.9725856206mm^2> Asmin4.3537414966149040-440013776.9045129875746558.33712733.9725856206-36966.59758562062733.9725856206Asmin=1/4(fc')(bwd)1.4(bwd)fyfy=1101.85025269911346.483251346.48325Therefore use As=2733.9725856206mm^2Using25mm dia,Ab =490.8738521234NoB =5.5696032164say7pcsSpacing:929.25=(75+12.5)(2) + (6)ss =125.7083333333say126mm< smaxok!smax =450mmTherefore use 7pcs 25mm dia bars sp.126mm O.C.Temperature and Shrinkage barsAts =0.0018bwt; bw =1000mmt =524mm=943.2mm^2Using16mm dia barsAb =201.0619298297Spacing:s=1000201.0619298297943.2s =213.1699849764say215mmTherefore use 16mm dia bars spaced215mmfor temperature and shrinkage

C1C2