footing
DESCRIPTION
footing design can be madeTRANSCRIPT
Design of Square footing for a Rectan Sloped footingfck 20
fckcolumn 20
fy 415dia of rod 12 mmcover 50 mmLoad on Column 550 kNAssme DL(10%) 55 kNTotal load 605 kN
SBC of soil 150
Area of footing required 4.03b column 230 mm 380D column 380 mmb@bottom of column(resisting section) 380 mmD@bottom of column(resisting section) 530 mmB 2.01 mProvide B 2.00 m
Net upward pressure 206.250net cantilever on xx 0.810 mnet cantilever on yy 0.885 mfactored B.M xx 135.32 kNmfactored B.M yy 161.54 kNmd required xx 304.15 mmd required yy 392.46 mmProvideover all depth 600 mm
150 mm
450 mmd provided 544 mm
Ast required xx 727Ast required yy 905
Minm steel required 591
Steel to be provided 905No of 12 mm bars required 18 nosSpacing of 12 mm bars 106 mmProvide12 mm bars 100 mm c/c
Ast provided 1131check for development length
SIGMAs 361.05
Tbd 1.92Development length 564 mmAvailable anchorage perpen to xx 760 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 835 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm factored shear at 544 mm from face of co 140.66 kNb 1468 mm
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
d 268 mmpt 0.29 %
Tc 0.38
Actual shear stress Tv 0.36Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 677.49 kNd 406 mmb 3396 mm
Actual shear stress Tv 0.49Calculation of Design Shear strength=KsTcBc 0.61Ks 1.00
Tc 1.12
KsTc(cl. 31.6.3 of IS 456:2000) 1.12Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.3046Weight of footing 32.62 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
4
0.0874
2
1573.2 kNCompare with Pu Allow bearing force on footing>Pu, O.K
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fck*Acolumn
Design of Square footing for a Squar Sloped footingfck 15
fckcolumn 20
fy 415dia of rod 10 mmcover 50 mmLoad on Column 800 kNAssme DL(10%) 80 kNTotal load 880 kN
SBC of soil 200
Area of footing required 4.40b column 350 mmD column 350 mmb@bottom of column(resisting section) 500 mmD@bottom of column(resisting section) 500 mmB 2.10 mProvide B 2.10 m
Net upward pressure 181.41net cantilever on xx 0.875 mnet cantilever on yy 0.875 mMaxm B.M 218.75 kNmd required 459.73 mmProvideover all depth 700 mm
230 mm
470 mmd provided 635 mm
Ast required 1051
Minm steel required 651
Steel to be provided 1051No of 10 mm bars required 14 nosSpacing of 10 mm bars 143 mmMaxm spacing for f415 180 mmProvide10 mm bars 140 mm c/c
Ast provided 1178check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mmAvailable anchorage perpen to xx 825 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 825 mm
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
N/mm2
N/mm2
Compare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 635 mm from face of column 137.14 kNb 1620 mmd 294 mmpt 0.25 %
Tc 0.35
Actual shear stress Tv 0.29Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 935.99 kNd 465 mmb 3940 mm
Actual shear stress Tv 0.51Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.8395Weight of footing 45.99 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
4.41
0.1225
2
1653.75 kNCompare with Pu Allow bearing force on footing>Pu, O.K
1102.5 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 97.5 kNDowel area=force/0.75fy 313 mm2Minm dowel area=0.5%Acolumn 612.5 mm2Longitudinal renforcement of columns is to be extended in to the footingDowel length in footing(D+450) or dev.length whi 1150 mm
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Design of Square footing for a Squar Sloped footing with pedestalfck 15
fck column 20
fy 415dia of rod 10 mmcover 50 mmLoad on Column 800 kNAssme DL(10%) 80 kNTotal load 880 kN
SBC of soil 200
Area of footing required 4.40b column 350 mmD column 350 mmSize of pedestalb pedestal 650 mmD pedestal 650 mm
1.89tan alpha>= 3.32Projection of pedestal 150 mmDepth of pedestal 498 mmProvide depth of pedestal 600 mmb@bottom of column(resisting section) 800 mmD@bottom of column(resisting section) 800 mmB 2.10 mProvide B 2.10 m
Net upward pressure 181.41net cantilever on xx 0.725 mnet cantilever on yy 0.725 mMaxm B.M 150.18 kNmd required 301.14 mmProvideover all depth 550 mm
230 mm
320 mmd provided 485 mm
Ast required 918
Minm steel required 795
Steel to be provided 918No of 10 mm bars required 12 nos
N/mm2
N/mm2
N/mm2
kN/m2
m2
q0 N/mm2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
Spacing of 10 mm bars 167 mmMaxm spacing for f415 180 mmProvide10 mm bars 150 mm c/c
Ast provided 1100check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mmAvailable anchorage perpen to xx 675 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 675 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 485 mm from face of column 137.14 kNb 1620 mmd 271 mmpt 0.25 %
Tc 0.35
Actual shear stress Tv 0.31Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 849.46 kNd 378 mmb 4540 mm
Actual shear stress Tv 0.49Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.5762
volume of pedestal 0.1800Weight of footing 43.90 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
0.4225
0.1225
1.86
5304 kNCompare with Pu Allow bearing force on footing>Pu, O.K
3803 kNCompare with Pu Allow bearing force>Pu, O.K
mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
m3
A1=bplp m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Design of rectangular footing for a re Sloped footingfck 15
Column fck 30
fy 415dia of rod 12 mmcover 50 mmLoad on Column 2000 kNAssme DL(10%) 200 kNTotal load 2200 kN
SBC of soil 220
Area of footing required 10.00b column 250 mmD column 750 mmb@bottom of column(resisting section) 400 mmD@bottom of column(resisting section) 900 mmB(trial) 2.922 mB should be such that effective cantilevers on bo 10.00 O.KProvide B 2.95 mProvide L 3.45 m
Net upward pressure 196.51net cantilever on xx 1.35 mnet cantilever on yy 1.35 mMu,xx 792.39 kNmd required 978.26 mmMu,yy 926.69 kNmd required 705.28 mmd required(maxm of above both values) 978 mmProvideover all depth 1200 mm
230 mm
970 mmdxx provided 1144 mmd provided 1132 mm
Ast required for Mu,xx 2216
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
Minm steel required 928
Steel to be provided 2216No of 12 mm bars required 20 nosSpacing of 12 mm bars 143 mmMaxm spacing for f415 180 mmProvide12 mm bars 140 mm c/c
Ast provided 2383
Ast required for Mu,yy 2429
Minm steel required 2089
Steel to be provided 2429No of 12 mm bars required 22 nosSpacing of 12 mm bars 152 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 2601
SIGMAs 361.05
Tbd 1.6Development length 677 mmAvailable anchorage perpen to xx 1300 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1300 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 1132 mm from face of column 189.57 kNb 2514 mmd 325 mmpt 0.29 %
Tc 0.37
Actual shear stress Tv 0.23Compare Tv with Tc (O.K) Tv<TcAbout yy axis need not be checkedCheck for two way Shearcritical section is at d/2 from the face of the columnVu 2233.33 kNd 732 mmb 6528 mm
Actual shear stress Tv 0.47Calculation of Design Shear strength=KsTcBc 0.33Ks<=1 0.83
Tc( 0.25*sqrtfck) 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.81Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
6.4003Weight of footing 160.01 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
mm2
mm2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
10.1775
0.1875
2
2531.25 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 468.75
2531.25 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 468.75 kNDowel area=force/0.75fy 1506 mm2Minm dowel area=0.5%Acolumn 937.5 mm2Longitudinal renforcement of columns is to be extended in to the footingDowel length in footing(D+450) or dev.length whi 1650 mm
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Sloped footingfck 15
Column fck 25
fy 415dia of rod 12 mmcover 50 mmLoad on Column 600 kNAssme DL(10%) 60 kNTotal load 660 kN
100 kNm
SBC of soil 200
Area of footing required 3.30b column 230 mmD column 600 mmb@bottom of column(resisting section) 380 mmD@bottom of column(resisting section) 750 mmB(trial) 1.640 mB should be such that effective cantilevers on bo 3.30 O.KProvide B 1.70 mProvideL 2.70 mTrial for calculation of L L(trial) 2.65 m
Area of footing A 4.51
Z 1.99
P/A 146.50
M/Z 50.26
196.76 O.K
96.25 O.KNet upward pressures for footing design
Area of footing provided 4.59
179.13
Design of eccentrically loaded rectangular footing for a rectangular column
N/mm2
N/mm2
N/mm2
Mxx
kN/m2
m2
m2
m3
kN/m2
kN/m2
pmax
pmin
m2
pmax kN/m2
82.30net cantilever on xx 0.735 mnet cantilever on yy 1.05 m
141.48Mu,xx 137.85 kNmd required 418.62 mmMu,yy 143.00 kNmd required 303.50 mmd required(maxm of above both values) 419 mmProvideover all depth 800 mm
300 mm
500 mmdxx provided 744 mmdyy provided 732 mm
Ast required for Mu,xx(llel to long direction) 542
Minm steel required 570
Steel to be provided 570No of 12 mm bars required 6 nosSpacing of 12 mm bars 267 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 1282
Ast required for Mu,yy 557
Minm steel required 1125
Steel to be provided 1125No of 12 mm bars required 10 nosSpacing of 12 mm bars 260 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 1998
SIGMAs 361.05
Tbd 1.6Development length 677 mmAvailable anchorage perpen to xx 685 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1000 mmCompare Available anchorage with Dev.length O.KCheck for one way Shear
168.16Maxm shear at 744 mm from face of column 145.26 kNb 1694 mmd 390 mmpt 0.19 %
Tc 0.32
Actual shear stress Tv 0.22Compare Tv with Tc (O.K) Tv<TcAbout yy axis need not be checked
pmin kN/m2
pmax at face of column kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
pmax at d from face of column kN/m2
N/mm2
N/mm2
Check for two way Shearcritical section is at d/2 from the face of the column
154.82Vu 454.08 kNd 564 mmb 974 mm
Actual shear stress Tv 0.83Calculation of Design Shear strength=KsTcBc 0.38Ks<=1 0.88
Tc( 0.25*sqrtfck) 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.86Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
2.3400Weight of footing 58.50 kNCompare weight of footing with that assumed (O.K) less than assumed weight
Maxm twoway shear will be along x2x2 @d/2 from face of column
pmax at d from face of column kN/m2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
C
230
.....
Allow bearing force on footing>Pu, O.K
Allow bearing force on footing>Pu, O.K
Allow bearing force on footing>Pu, O.K
A
A1 C
Design of Square footing for a Recta Sloped footingfck 20
fckcolumn 20
fy 415dia of rod 8 mmcover 50 mmLoad on Column 90 kNAssme DL(10%) 9 kNTotal load 99 kN
SBC of soil 100
Area of footing required 0.99b column 230 mm 380D column 230 mm
230b@bottom of column(resisting section) 380 mmD@bottom of column(resisting section) 380 mmB 0.99 mProvide B 0.90 m
Net upward pressure 166.667net cantilever on xx 0.335 mnet cantilever on yy 0.335 mfactored B.M xx 8.42 kNmfactored B.M yy 8.42 kNmd required xx 89.58 mmd required yy 89.58 mmProvideover all depth 200 mm
200 mm
0 mmd provided 146 mm
Ast required xx 171 171Ast required yy 171
Minm steel required 114
Steel to be provided 171No of 8 mm bars required 3.6 nosSpacing of 8 mm bars 223 mmProvide8 mm bars 200 mm c/c
Ast provided 251check for development length
SIGMAs 361.05
Tbd 1.92Development length 376 mmAvailable anchorage perpen to xx 285 mmCompare Available anchorage with Dev.length Provide L bend of more than 91mmAvailable anchorage perpen to yy 285 mmCompare Available anchorage with Dev.length Provide L bend of more than 91mmCheck for one way ShearMaxm factored shear at 146 mm from face of co 28.35 kNb 522 mm
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
d 146 mmpt 0.33 %
Tc 0.4
Actual shear stress Tv 0.37Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 111.44 kNd 146 mmb 1504 mm
Actual shear stress Tv 0.51Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 1.12
KsTc(cl. 31.6.3 of IS 456:2000) 1.12Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
0.1620Weight of footing 4.05 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
0.81
0.0529
2
952.2 kNCompare with Pu Allow bearing force on footing>Pu, O.K
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fck*Acolumn
1 5*0.80.85 0.8* * 1
6.89*
FckFck
pt
( ) /( 6*.8*fck/( 6.89*pt) )
Design of Square footing for a Squar Sloped footingfck 15
fckcolumn 20
fy 415dia of rod 10 mmcover 50 mmLoad on Column 600 kNAssme DL(10%) 60 kNTotal load 660 kN
SBC of soil 200
Area of footing required 3.30b column 350 mmD column 350 mmb@bottom of column(resisting section) 500 mmD@bottom of column(resisting section) 500 mmB 1.82 mProvide B 1.90 m
Net upward pressure 166.20net cantilever on xx 0.775 mnet cantilever on yy 0.775 mMaxm B.M 142.25 kNm 1900d required 370.73 mmProvideover all depth 550 mm 350
230 mm 350
320 mmd provided 485 mm
Ast required 907
Minm steel required 497 775
Steel to be provided 907No of 10 mm bars required 12 nosSpacing of 10 mm bars 150 mmMaxm spacing for f415 180 mmProvide10 mm bars 140 mm c/c
Ast provided 1066check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mm 1900Available anchorage perpen to xx 725 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 725 mm
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
N/mm2
N/mm2
Compare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 485 mm from face of column 137.37 kNb 1320 mmd 285 mmpt 0.28 %
Tc 0.37
Actual shear stress Tv 0.37Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 726.18 kNd 385 mmb 3340 mm
Actual shear stress Tv 0.56Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.2994Weight of footing 32.48 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
3.61
0.1225
2
1653.75 kNCompare with Pu Allow bearing force on footing>Pu, O.K
1102.5 kNCompare with Pu Allow bearing force>Pu, O.K
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Design of Square footing for a Squar Sloped footing with pedestalfck 15
fck column 20
fy 415dia of rod 10 mmcover 50 mmLoad on Column 800 kNAssme DL(10%) 80 kNTotal load 880 kN
SBC of soil 200
Area of footing required 4.40b column 350 mmD column 350 mmSize of pedestalb pedestal 650 mmD pedestal 650 mm
1.89tan alpha>= 3.32Projection of pedestal 150 mmDepth of pedestal 498 mmProvide depth of pedestal 600 mmb@bottom of column(resisting section) 800 mmD@bottom of column(resisting section) 800 mmB 2.10 mProvide B 2.10 m
Net upward pressure 181.41net cantilever on xx 0.725 mnet cantilever on yy 0.725 mMaxm B.M 150.18 kNmd required 301.14 mmProvideover all depth 550 mm
230 mm
320 mmd provided 485 mm
Ast required 918
Minm steel required 795
N/mm2
N/mm2
N/mm2
kN/m2
m2
q0 N/mm2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
Steel to be provided 918No of 10 mm bars required 12 nosSpacing of 10 mm bars 167 mmMaxm spacing for f415 180 mmProvide10 mm bars 150 mm c/c
Ast provided 1100check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mmAvailable anchorage perpen to xx 675 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 675 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 485 mm from face of column 137.14 kNb 1620 mmd 271 mmpt 0.25 %
Tc 0.35
Actual shear stress Tv 0.31Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 849.46 kNd 378 mmb 4540 mm
Actual shear stress Tv 0.49Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.5762
volume of pedestal 0.1800Weight of footing 43.90 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
0.4225
0.1225
1.86
5304 kNCompare with Pu Allow bearing force on footing>Pu, O.K
3803 kNCompare with Pu Allow bearing force>Pu, O.K
mm2
mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
m3
A1=bplp m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Design of rectangular footing for a r Sloped footingfck 15
Column fck 30
fy 415dia of rod 12 mmcover 50 mmLoad on Column 2000 kNAssme DL(10%) 200 kNTotal load 2200 kN
SBC of soil 220
Area of footing required 10.00b column 250 mmD column 750 mmb@bottom of column(resisting section) 400 mmD@bottom of column(resisting section) 900 mmB(trial) 2.922 mB should be such that effective cantilevers on bo 10.00 O.KProvide B 2.95 mProvide L 3.45 m
Net upward pressure 196.51net cantilever on xx 1.35 mnet cantilever on yy 1.35 mMu,xx 792.39 kNmd required 978.26 mmMu,yy 926.69 kNmd required 705.28 mmd required(maxm of above both values) 978 mmProvideover all depth 1200 mm
230 mm
970 mmdxx provided 1144 mm
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
d provided 1132 mm
Ast required for Mu,xx 2216
Minm steel required 928
Steel to be provided 2216No of 12 mm bars required 20 nosSpacing of 12 mm bars 143 mmMaxm spacing for f415 180 mmProvide12 mm bars 140 mm c/c
Ast provided 2383
Ast required for Mu,yy 2429
Minm steel required 2089
Steel to be provided 2429No of 12 mm bars required 22 nosSpacing of 12 mm bars 152 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 2601
SIGMAs 361.05
Tbd 1.6Development length 677 mmAvailable anchorage perpen to xx 1300 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1300 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 1132 mm from face of column 189.57 kNb 2514 mmd 325 mmpt 0.29 %
Tc 0.37
Actual shear stress Tv 0.23Compare Tv with Tc (O.K) Tv<TcAbout yy axis need not be checkedCheck for two way Shearcritical section is at d/2 from the face of the columnVu 2233.33 kNd 732 mmb 6528 mm
Actual shear stress Tv 0.47Calculation of Design Shear strength=KsTcBc 0.33Ks<=1 0.83
Tc( 0.25*sqrtfck) 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.81Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
6.4003Weight of footing 160.01 kNCompare weight of footing with that assumed (O.K) less than assumed weight
mm2
mm2
mm2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
Transfer of load from pedestal to footing
10.1775
0.1875
2
2531.25 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 468.75
2531.25 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 468.75 kNDowel area=force/0.75fy 1506 mm2Minm dowel area=0.5%Acolumn 937.5 mm2Longitudinal renforcement of columns is to be extended in to the footingDowel length in footing(D+450) or dev.length wh 1650 mm
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Sloped footingfck 15
Column fck 25
fy 415dia of rod 12 mmcover 50 mmLoad on Column 600 kNAssme DL(10%) 60 kNTotal load 660 kN
100 kNm
SBC of soil 200
Area of footing required 3.30b column 230 mmD column 600 mmb@bottom of column(resisting section) 380 mmD@bottom of column(resisting section) 750 mmB(trial) 1.640 mB should be such that effective cantilevers on bo 3.30 O.KProvide B 1.70 mProvideL 2.70 mTrial for calculation of L L(trial) 2.65 m
Area of footing A 4.51
Z 1.99
P/A 146.50
M/Z 50.26
196.76 O.K
96.25 O.KNet upward pressures for footing design
Area of footing provided 4.59
179.13
Design of eccentrically loaded rectangular footing for a rectangular column
N/mm2
N/mm2
N/mm2
Mxx
kN/m2
m2
m2
m3
kN/m2
kN/m2
pmax
pmin
m2
pmax kN/m2
82.30net cantilever on xx 0.735 mnet cantilever on yy 1.05 m
141.48Mu,xx 137.85 kNmd required 418.62 mmMu,yy 143.00 kNmd required 303.50 mmd required(maxm of above both values) 419 mmProvideover all depth 800 mm
300 mm
500 mmdxx provided 744 mmdyy provided 732 mm
Ast required for Mu,xx(llel to long direction) 542
Minm steel required 570
Steel to be provided 570No of 12 mm bars required 6 nosSpacing of 12 mm bars 267 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 1282
Ast required for Mu,yy 557
Minm steel required 1125
Steel to be provided 1125No of 12 mm bars required 10 nosSpacing of 12 mm bars 260 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 1998
SIGMAs 361.05
Tbd 1.6Development length 677 mmAvailable anchorage perpen to xx 685 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1000 mmCompare Available anchorage with Dev.length O.KCheck for one way Shear
168.16Maxm shear at 744 mm from face of column 145.26 kNb 1694 mmd 390 mmpt 0.19 %
Tc 0.32
Actual shear stress Tv 0.22Compare Tv with Tc (O.K) Tv<TcAbout yy axis need not be checked
pmin kN/m2
pmax at face of column kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
pmax at d from face of column kN/m2
N/mm2
N/mm2
Check for two way Shearcritical section is at d/2 from the face of the column
154.82Vu 454.08 kNd 564 mmb 974 mm
Actual shear stress Tv 0.83Calculation of Design Shear strength=KsTcBc 0.38Ks<=1 0.88
Tc( 0.25*sqrtfck) 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.86Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
2.3400Weight of footing 58.50 kNCompare weight of footing with that assumed (O.K) less than assumed weight
Maxm twoway shear will be along x2x2 @d/2 from face of column
pmax at d from face of column kN/m2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A
1 5*0.80.85 0.8* * 1
6.89*
FckFck
pt
( ) /( 6*.8*fck/( 6.89*pt) )
1900
775
320
230
C
Design of Square footing for a Recta Sloped footingfck 15
fckcolumn 15
fy 415dia of rod 10 mmcover 35 mmLoad on Column 1000 kNAssme DL(10%) 100 kNTotal load 1100 kN
SBC of soil 100
Area of footing required 11.00b column 400 mm 400D column 400 mm
230b@bottom of column(resisting section) 550 mmD@bottom of column(resisting section) 550 mmB 3.32 mProvide B 3.50 m
Net upward pressure 122.449net cantilever on xx 1.550 mnet cantilever on yy 1.55 mfactored B.M xx 514.82 kNmfactored B.M yy 514.82 kNmd required xx 266.57 mmd required yy 266.57 mmProvideover all depth 600 mmd provided 560 mm
Ast required xx 2646 3947Ast required yy
Minm steel required 631
Steel to be provided 2646No of 10 mm bars required 34 nosSpacing of 10 mm bars 101 mmProvide10 mm bars 100 mm c/c
Ast provided 2747.5check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mmAvailable anchorage perpen to xx 1500 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1500 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm factored shear at 560 mm from face of co 424.29 kNb 3500 mmd 560 mmpt 0.14 %
Tc 0.27
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
N/mm21 5*0.8
0.85 0.8* * 16.89*
FckFck
pt
( ) /( 6*.8*fck/( 6.89*pt) )
Actual shear stress Tv 0.22Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 1387.15 kNd 560 mmb 3840 mm
Actual shear stress Tv 0.65Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
7.3500Weight of footing 183.75 kNCompare weight of footing with that assumed Not O.K,More than assumed weight Transfer of load from column to footing
7.84
0.16
2
2160 kNCompare with Pu Allow bearing force on footing>Pu, O.K
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fck*Acolumn
1 5*0.80.85 0.8* * 1
6.89*
FckFck
pt
( ) /( 6*.8*fck/( 6.89*pt) )
Design of Square footing for a Squar Sloped footingfck 15
fckcolumn 20
fy 415dia of rod 10 mmcover 50 mmLoad on Column 600 kNAssme DL(10%) 60 kNTotal load 660 kN
SBC of soil 200
Area of footing required 3.30b column 350 mmD column 350 mmb@bottom of column(resisting section) 500 mmD@bottom of column(resisting section) 500 mmB 1.82 mProvide B 1.90 m
Net upward pressure 166.20net cantilever on xx 0.775 mnet cantilever on yy 0.775 mMaxm B.M 142.25 kNm 1900d required 370.73 mmProvideover all depth 550 mm 350
230 mm 350
320 mmd provided 485 mm
Ast required 907
Minm steel required 497 775
Steel to be provided 907No of 10 mm bars required 12 nosSpacing of 10 mm bars 150 mmMaxm spacing for f415 180 mmProvide10 mm bars 140 mm c/c
Ast provided 1066check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mm 1900Available anchorage perpen to xx 725 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 725 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 485 mm from face of column 137.37 kN
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
N/mm2
N/mm2
b 1320 mmd 285 mmpt 0.28 %
Tc 0.37
Actual shear stress Tv 0.37Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 726.18 kNd 385 mmb 3340 mm
Actual shear stress Tv 0.56Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.2994Weight of footing 32.48 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
3.61
0.1225
2
1653.75 kNCompare with Pu Allow bearing force on footing>Pu, O.K
1102.5 kNCompare with Pu Allow bearing force>Pu, O.K
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Design of Square footing for a Squar Sloped footing with pedestalfck 15
fck column 20
fy 415dia of rod 10 mmcover 50 mmLoad on Column 800 kNAssme DL(10%) 80 kNTotal load 880 kN
SBC of soil 200
Area of footing required 4.40b column 350 mmD column 350 mmSize of pedestalb pedestal 650 mmD pedestal 650 mm
1.89tan alpha>= 3.32Projection of pedestal 150 mmDepth of pedestal 498 mmProvide depth of pedestal 600 mmb@bottom of column(resisting section) 800 mmD@bottom of column(resisting section) 800 mmB 2.10 mProvide B 2.10 m
Net upward pressure 181.41net cantilever on xx 0.725 mnet cantilever on yy 0.725 mMaxm B.M 150.18 kNmd required 301.14 mmProvideover all depth 550 mm
230 mm
320 mmd provided 485 mm
Ast required 918
Minm steel required 795
Steel to be provided 918No of 10 mm bars required 12 nosSpacing of 10 mm bars 167 mm
N/mm2
N/mm2
N/mm2
kN/m2
m2
q0 N/mm2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
Maxm spacing for f415 180 mmProvide10 mm bars 150 mm c/c
Ast provided 1100check for development length
SIGMAs 361.05
Tbd 1.6Development length 564 mmAvailable anchorage perpen to xx 675 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 675 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 485 mm from face of column 137.14 kNb 1620 mmd 271 mmpt 0.25 %
Tc 0.35
Actual shear stress Tv 0.31Compare Tv with Tc (O.K) Tv<TcCheck for two way Shearcritical section is at d/2 from the face of the columnVu 849.46 kNd 378 mmb 4540 mm
Actual shear stress Tv 0.49Calculation of Design Shear strength=KsTcBc 1.00Ks 1.00
Tc 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.97Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
1.5762
volume of pedestal 0.1800Weight of footing 43.90 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
0.4225
0.1225
1.86
5304 kNCompare with Pu Allow bearing force on footing>Pu, O.K
3803 kNCompare with Pu Allow bearing force>Pu, O.K
mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
m3
A1=bplp m2
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Design of rectangular footing for a r Sloped footingfck 15
Column fck 30
fy 415dia of rod 12 mmcover 50 mmLoad on Column 2000 kNAssme DL(10%) 200 kNTotal load 2200 kN
SBC of soil 220
Area of footing required 10.00b column 250 mmD column 750 mmb@bottom of column(resisting section) 400 mmD@bottom of column(resisting section) 900 mmB(trial) 2.922 mB should be such that effective cantilevers on bo 10.00 O.KProvide B 2.95 mProvide L 3.45 m
Net upward pressure 196.51net cantilever on xx 1.35 mnet cantilever on yy 1.35 mMu,xx 792.39 kNmd required 978.26 mmMu,yy 926.69 kNmd required 705.28 mmd required(maxm of above both values) 978 mmProvideover all depth 1200 mm
230 mm
970 mmdxx provided 1144 mmd provided 1132 mm
Ast required for Mu,xx 2216
Minm steel required 928
N/mm2
N/mm2
N/mm2
kN/m2
m2
kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
Steel to be provided 2216No of 12 mm bars required 20 nosSpacing of 12 mm bars 143 mmMaxm spacing for f415 180 mmProvide12 mm bars 140 mm c/c
Ast provided 2383
Ast required for Mu,yy 2429
Minm steel required 2089
Steel to be provided 2429No of 12 mm bars required 22 nosSpacing of 12 mm bars 152 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 2601
SIGMAs 361.05
Tbd 1.6Development length 677 mmAvailable anchorage perpen to xx 1300 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1300 mmCompare Available anchorage with Dev.length O.KCheck for one way ShearMaxm shear at 1132 mm from face of column 189.57 kNb 2514 mmd 325 mmpt 0.29 %
Tc 0.37
Actual shear stress Tv 0.23Compare Tv with Tc (O.K) Tv<TcAbout yy axis need not be checkedCheck for two way Shearcritical section is at d/2 from the face of the columnVu 2233.33 kNd 732 mmb 6528 mm
Actual shear stress Tv 0.47Calculation of Design Shear strength=KsTcBc 0.33Ks<=1 0.83
Tc( 0.25*sqrtfck) 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.81Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
6.4003Weight of footing 160.01 kNCompare weight of footing with that assumed (O.K) less than assumed weightTransfer of load from pedestal to footing
10.1775
mm2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A1=bflf or (bc+4D)*(lc+4D),which ever is less m2
0.1875
2
2531.25 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 468.75
2531.25 kNCompare with Pu Not O.K, Dowels are requiredForce in dowel bars 468.75 kNDowel area=force/0.75fy 1506 mm2Minm dowel area=0.5%Acolumn 937.5 mm2Longitudinal renforcement of columns is to be extended in to the footingDowel length in footing(D+450) or dev.length wh 1650 mm
A2=bclc m2
Sqrt(A1/A2)<=2
Allowable bearing force on footing =Sqrt(A1/A2)*0.45fckAcolumn
Allowable bearing force at base of column =0.45fckcol*Acolumn
Sloped footingfck 15
Column fck 25
fy 415dia of rod 12 mmcover 50 mmLoad on Column 600 kNAssme DL(10%) 60 kNTotal load 660 kN
100 kNm
SBC of soil 200
Area of footing required 3.30b column 230 mmD column 600 mmb@bottom of column(resisting section) 380 mmD@bottom of column(resisting section) 750 mmB(trial) 1.640 mB should be such that effective cantilevers on bo 3.30 O.KProvide B 1.70 mProvideL 2.70 mTrial for calculation of L L(trial) 2.65 m
Area of footing A 4.51
Z 1.99
P/A 146.50
M/Z 50.26
196.76 O.K
96.25 O.KNet upward pressures for footing design
Area of footing provided 4.59
179.13
82.30net cantilever on xx 0.735 m
Design of eccentrically loaded rectangular footing for a rectangular column
N/mm2
N/mm2
N/mm2
Mxx
kN/m2
m2
m2
m3
kN/m2
kN/m2
pmax
pmin
m2
pmax kN/m2
pmin kN/m2
net cantilever on yy 1.05 m
141.48Mu,xx 137.85 kNmd required 418.62 mmMu,yy 143.00 kNmd required 303.50 mmd required(maxm of above both values) 419 mmProvideover all depth 800 mm
300 mm
500 mmdxx provided 744 mmdyy provided 732 mm
Ast required for Mu,xx(llel to long direction) 542
Minm steel required 570
Steel to be provided 570No of 12 mm bars required 6 nosSpacing of 12 mm bars 267 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 1282
Ast required for Mu,yy 557
Minm steel required 1125
Steel to be provided 1125No of 12 mm bars required 10 nosSpacing of 12 mm bars 260 mmMaxm spacing for f415 180 mmProvide12 mm bars 150 mm c/c
Ast provided 1998
SIGMAs 361.05
Tbd 1.6Development length 677 mmAvailable anchorage perpen to xx 685 mmCompare Available anchorage with Dev.length O.KAvailable anchorage perpen to yy 1000 mmCompare Available anchorage with Dev.length O.KCheck for one way Shear
168.16Maxm shear at 744 mm from face of column 145.26 kNb 1694 mmd 390 mmpt 0.19 %
Tc 0.32
Actual shear stress Tv 0.22Compare Tv with Tc (O.K) Tv<TcAbout yy axis need not be checked
pmax at face of column kN/m2
Plain depth(h1)
Sloped depth(h2)
mm2
mm2
mm2
mm2
mm2
mm2
mm2
mm2
N/mm2
N/mm2
pmax at d from face of column kN/m2
N/mm2
N/mm2
Check for two way Shearcritical section is at d/2 from the face of the column
154.82Vu 454.08 kNd 564 mmb 974 mm
Actual shear stress Tv 0.83Calculation of Design Shear strength=KsTcBc 0.38Ks<=1 0.88
Tc( 0.25*sqrtfck) 0.97
KsTc(cl. 31.6.3 of IS 456:2000) 0.86Compare Tv with KsTc (O.K) Tv<KsTcCheck for weight of base
2.3400Weight of footing 58.50 kNCompare weight of footing with that assumed (O.K) less than assumed weight
Maxm twoway shear will be along x2x2 @d/2 from face of column
pmax at d from face of column kN/m2
N/mm2
N/mm2
N/mm2
Voiume of footing A12h1+ h2/6(A1+A2+4Am) m3
A
1 5*0.80.85 0.8* * 1
6.89*
FckFck
pt
( ) /( 6*.8*fck/( 6.89*pt) )
1 5*0.80.85 0.8* * 1
6.89*
FckFck
pt
( ) /( 6*.8*fck/( 6.89*pt) )
1900
775
320
230