DESIGN OF COMBINE FOOTING GRID REF.NO DESIGN CALCULATION: CF1 LOAD ON COLUMN C1 W1 = 350 KN FCK 20 LOAD ON COLUMN C2 W2 = 350 KN SELF WT. OF FOOTING 70 KN TOTAL DESIGN LOAD ON FOOTING(P)= 770 KN S.B.C OF SOIL = 150 KN/M2 REQ.AREA OF FOOTING = P/S.B.C 5.1333333 M2 FOOTING SIZE PROV. L = 3 M B = 2 AREA OF FOOTING PROVIDED = 6 M2 AREA PROV > AREA REQ. CENTER TO CENTER DIST. BET.COLUMN(b) = 1.2 M GEOMETRIC CENTER ,G.C =b/2 0.6 M (X)DIST. OF C.G OF COLM.FROM CENTER OF FOOTING(X)=W2Xb/(W1+W2)= 0.6 M PROJ.a1 FROM CENTER OF COLUMN (C2)= a1 =(L/2-X) = 0.9 M PROJ.a2 FROM CENTER OF COLUMN (C1)= a2=(L-a1-b) = 0.9 M NET UPWARD PRESSURE(QNET)=(W1+W2)/(A PROV)= 116.6667 KN/M2 MINI.ECCEN.Emin =.02M 0.02 M MOMENT DUE TO Emini = 14 KN-M AVAILABLE ECCEN, =(b/2-x)= 0 M MOMENT DUE TO AVAILABLE ECCE.= 0 KN-M CONSIDERING FULL WIDTH OF FOOTING BM CALCULATION: QNET = 116.667 KN/M2 MAX PRESSURE =QNET+6XM/BXLXL 121.33333 KN/M MINI PRESSURE = QNET-6XM/BXLXL 112 KN/M STRIP PRESSURE(q)=QNETXB = 233.33333 KN/M SHEAR FORCE V1=qxa1= 210 KN V2 =W1-V1 140 KN V3 =qxa2 = 210 KN V4=W2-V2= 210 KN POSITION OF ZERO SHEAR (Y)=(W1-q*a1)/q Y = 0.6 M BENDING MOMENT CALCULATION: M1 = q*a1*a1/2KN-M 94.5 KNM M2 = q*a2*a2/2KN-M 94.5 KN-M M3 = q*(y+a1)2/2-w1*y KN-M 52.5 KN-M MAX. SAGGING BEND.MOM 94.5 KN-M IS 456 1978 APPENDIX E CLAUSE 37.1 EFF.DEPTH FROM MAX BENDING MOMENT CONSIDARATION: d=sqrt(mu*1000000/(.138*fck*B))= 130.84176 PROVIDE D = 500 MM d =D-50-10 440 K= MU/B*d = 0.24405992 Pt FROM TABLE 2 SP 16 IS 456 1978 Pt minimum according to IS 456 1978

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DESIGN OF COMBINE FOOTING

GRIDREF.NO DESIGN CALCULATION:CF1 LOAD ON COLUMN C1 W1 = 350 KN FCK 20 MPA

LOAD ON COLUMN C2 W2 = 350 KNSELF WT. OF FOOTING 70 KNTOTAL DESIGN LOAD ON FOOTING(P)= 770 KNS.B.C OF SOIL = 150 KN/M2REQ.AREA OF FOOTING = P/S.B.C 5.1333333 M2FOOTING SIZE PROV. L = 3 M B = 2 MAREA OF FOOTING PROVIDED = 6 M2

AREA PROV > AREA REQ.CENTER TO CENTER DIST. BET.COLUMN(b) = 1.2 MGEOMETRIC CENTER ,G.C =b/2 0.6 M(X)DIST. OF C.G OF COLM.FROM CENTER OF FOOTING(X)=W2Xb/(W1+W2)=

0.6 MPROJ.a1 FROM CENTER OF COLUMN (C2)=a1 =(L/2-X) = 0.9 MPROJ.a2 FROM CENTER OF COLUMN (C1)=a2=(L-a1-b) = 0.9 MNET UPWARD PRESSURE(QNET)=(W1+W2)/(A PROV)=

116.6667 KN/M2MINI.ECCEN.Emin =.02M 0.02 MMOMENT DUE TO Emini = 14 KN-MAVAILABLE ECCEN, =(b/2-x)= 0 MMOMENT DUE TO AVAILABLE ECCE.= 0 KN-MCONSIDERING FULL WIDTH OF FOOTINGBM CALCULATION:QNET = 116.667 KN/M2MAX PRESSURE =QNET+6XM/BXLXL 121.33333 KN/MMINI PRESSURE = QNET-6XM/BXLXL 112 KN/MSTRIP PRESSURE(q)=QNETXB = 233.33333 KN/MSHEAR FORCE V1=qxa1= 210 KN

V2 =W1-V1 140 KNV3 =qxa2 = 210 KNV4=W2-V2= 210 KN

POSITION OF ZERO SHEAR (Y)=(W1-q*a1)/qY = 0.6 M

BENDING MOMENT CALCULATION:M1 = q*a1*a1/2 KN-M 94.5 KNMM2 = q*a2*a2/2 KN-M 94.5 KN-MM3 = q*(y+a1)2/2-w1*y KN-M 52.5 KN-M

MAX. SAGGING BEND.MOM 94.5 KN-MIS 456 1978 APPENDIX E CLAUSE 37.1EFF.DEPTH FROM MAX BENDING MOMENT CONSIDARATION:d=sqrt(mu*1000000/(.138*fck*B))= 130.84176PROVIDE D = 500 MM d =D-50-10 440K= MU/B*d = 0.244059917Pt FROM TABLE 2 SP 16 IS 456 1978Pt minimum according to IS 456 1978

Pt = 0.15 %AST=Pt*B*d/100 1320 MM2 AST RQEUSE 14 MM BARS 153.86 MM2

PROVIDE AT 160 C/C MM

AST PROVD. 1923.25 MM2> AST REQ OKCHECK FOR SHEAR (ONE WAY SHEAR)AT d FROM FACE OF COLUMN NO 1

VU= QNET*(a1-d)= 53.66666667 KNSHEAR STRESS=VU/Bd= 0.06098 MPAVd<1.5Vc hence okCHECK FOR SHEAR (TWO WAY SHEAR)AT d/2 FROM FACE OF COLUMN NO 1SIZE OF COLUMNSC1 200 400 MMC2 200 400 MMb+d 640 MMh+d 840 MMCIRCUMFERENCE © =(b+d+h+d)*2

2960 MMPUNCHING FORCE = W1-QNET*((b+d)*(h+d))

287.28 KNSHEAR STRESS= 287.28/C*d

0.220577396P.STRESS AT d/2 < 3Vc OKEFF.DEPTH FROM PUNCHING SHEARd=(w1*1000)/(b+D+h+D) 291.667 MM

d prov > dreq hence ok