copy of rectangular tapered footing.xls
TRANSCRIPT
F 1 0.300
0.450
0.3000.450
0.500
0.650
2.100
2.100
0.450
0.250
0.000
2.679
0.050
0.050
0.400
0.400
2.500
1.800
500
Wt. of footing (t) = 3.747 25
Wt. of soil over footing (t) = 17.152 10.0
20.899 14.8222
= 26.723 Node 6
= 1.808 Load Case 6
= 0.035
47.621
= 1.5
0
11.99 9.65 11.95 9.60
4.74
M (t-m) = 4.95 5.17
7.42 7.75
0.928 0.745
0.223 0.178
447 462
V (t) = 6.24 6.38
9.36 9.57
1.162 1.194
0.317 0.325
0.153 0.153
0.038 0.037
733 751
38.15
0.461 1.250
Hence OK
DESIGN OF FOOTING MARKED :- cl (m) =
cb (m) =
l (m) =b (m) =
l' (m) =
b' (m) =
L (m) =
B (m) =
D1 (m) =
D2 (m) =
Dp (m) =
Depth of foundation 'DF' below G.L (m) =
clear cover cx to R/F for forces about X-axis (m) =
clear cover cy to R/F for forces about Y-axis (m) =
effective depth 'd1' for forces about X-axis (m) =
effective depth 'd2' for forces about Y-axis (m) =
Unit wt. of Conc.'gc' (t/m3) =
Unit wt. of Soil. 'gs' (t/m3) =
Self wt. of footing and weight of soil on footing: fy (N/mm2) =
fck (N/mm2) =
Net Bearing Capacity 'qnet'
(t/m2) =
Footing Wt.+Soil Wt.= (P1 )(t) =
Gross Bearing Capacity 'qgross'
=(qnet+DF x gs )(t/m2) =
Static case :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=
d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
My
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
MZ
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
Node 6L/C 9
= 28.688
= 1.929
= 3.931
49.587
= 1.5
25
15.04 12.54 9.95 7.45
4.74
M (t-m) = 5.31 7.08
7.96 10.62
0.995 1.021
0.240 0.247
481 642
V (t) = 6.70 8.87
10.04 13.30
1.162 1.1940.317 0.325
0.164 0.213
0.044 0.075
733 751
38.15
0.461 1.250
Hence OK
Seismic/Wind case in X-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
a b c d a
a b c d a
Node 6L/C 8
= 27.658
= 7.790
= 0.045
48.557
= 1.5
25
16.09 5.99 16.03 5.93
4.74
M (t-m) = 7.14 5.35
10.72 8.03
1.340 0.772
0.330 0.184
660 479
V (t) = 9.19 6.61
13.79 9.91
1.162 1.1940.317 0.325
0.226 0.158
0.086 0.040
733 751
38.15
0.461 1.250
Hence OK
R/F REQD 733.47 751.03
R/F PROVIDED 1373.75 1373.75Provided 10 dia @ 120 Provided 10 dia @ 120
Ast = 654 Ast = 654
Seismic/Wind case in Y-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
mm2/m mm2/m
a b c d a
a b c d a
F 2 0.450
0.300
0.4500.300
0.650
0.500
2.400
2.400
0.600
0.300
0.000
2.679
0.050
0.050
0.550
0.550
2.500
1.800
500
Wt. of footing (t) = 6.186 25
Wt. of soil over footing (t) = 21.050 10.0
27.236 14.8222
= 36.074 Node 11
= 0.214 Load Case 6
= 1.658
63.310
= 1.5
0
11.80 11.62 10.36 10.18
4.73
M (t-m) = 8.37 7.74
12.56 11.61
0.639 0.768
0.151 0.183
541 504
V (t) = 7.60 6.99
11.41 10.49
1.479 1.477
0.408 0.396
0.126 0.119
0.025 0.022
1087 1059
49.10
0.362 1.250
Hence OK
DESIGN OF FOOTING MARKED :- cl (m) =
cb (m) =
l (m) =b (m) =
l' (m) =
b' (m) =
L (m) =
B (m) =
D1 (m) =
D2 (m) =
Dp (m) =
Depth of foundation 'DF' below G.L (m) =
clear cover cx to R/F for forces about X-axis (m) =
clear cover cy to R/F for forces about Y-axis (m) =
effective depth 'd1' for forces about X-axis (m) =
effective depth 'd2' for forces about Y-axis (m) =
Unit wt. of Conc.'gc' (t/m3) =
Unit wt. of Soil. 'gs' (t/m3) =
Self wt. of footing and weight of soil on footing: fy (N/mm2) =
fck (N/mm2) =
Net Bearing Capacity 'qnet'
(t/m2) =
Footing Wt.+Soil Wt.= (P1 )(t) =
Gross Bearing Capacity 'qgross'
=(qnet+DF x gs )(t/m2) =
Static case :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=
d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
My
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
MZ
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
Node 11L/C 9
= 41.862
= 0.257
= 7.649
69.098
= 1.5
25
15.43 15.20 8.79 8.56
4.73
M (t-m) = 9.72 11.05
14.58 16.58
0.741 1.096
0.177 0.266
632 732
V (t) = 8.83 10.20
13.24 15.30
1.479 1.4770.408 0.396
0.146 0.173
0.034 0.049
1087 1059
49.10
0.362 1.250
Hence OK
Seismic/Wind case in X-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
a b c d a
a b c d a
Node 11L/C 10
= 36.880
= 3.536
= 1.687
64.116
= 1.5
25
13.40 10.33 11.93 8.86
4.73
M (t-m) = 9.91 7.91
14.86 11.87
0.756 0.785
0.180 0.187
645 516
V (t) = 9.14 7.15
13.71 10.72
1.479 1.4770.408 0.396
0.151 0.121
0.037 0.023
1087 1059
49.10
0.362 1.250
Hence OK
R/F REQD 1087.48 1058.97
R/F PROVIDED 1884.00 1884.00Provided 10 dia @ 100 Provided 10 dia @ 100
Ast = 785 Ast = 785
Seismic/Wind case in Y-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
mm2/m mm2/m
a b c d a
a b c d a
F 3 0.380
0.600
0.3800.600
0.580
0.800
2.700
2.700
0.600
0.300
0.000
2.679
0.050
0.050
0.550
0.550
2.500
1.800
500
Wt. of footing (t) = 7.872 25
Wt. of soil over footing (t) = 26.427 10.0
34.299 14.8222
= 45.522 Node 3
= 1.306 Load Case 6
= 0.092
79.821
= 1.5
0
11.38 10.58 11.32 10.52
4.70
M (t-m) = 9.73 11.38
14.60 17.07
0.832 0.705
0.199 0.168
636 738
V (t) = 8.87 10.32
13.30 15.48
1.584 1.607
0.408 0.423
0.131 0.148
0.027 0.035
1216 1256
62.21
0.408 1.250
Hence OK
DESIGN OF FOOTING MARKED :- cl (m) =
cb (m) =
l (m) =b (m) =
l' (m) =
b' (m) =
L (m) =
B (m) =
D1 (m) =
D2 (m) =
Dp (m) =
Depth of foundation 'DF' below G.L (m) =
clear cover cx to R/F for forces about X-axis (m) =
clear cover cy to R/F for forces about Y-axis (m) =
effective depth 'd1' for forces about X-axis (m) =
effective depth 'd2' for forces about Y-axis (m) =
Unit wt. of Conc.'gc' (t/m3) =
Unit wt. of Soil. 'gs' (t/m3) =
Self wt. of footing and weight of soil on footing: fy (N/mm2) =
fck (N/mm2) =
Net Bearing Capacity 'qnet'
(t/m2) =
Footing Wt.+Soil Wt.= (P1 )(t) =
Gross Bearing Capacity 'qgross'
=(qnet+DF x gs )(t/m2) =
Static case :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=
d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
My
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
MZ
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
Node 3L/C 7
= 45.058
= 1.380
= 7.684
79.357
= 1.5
25
13.65 12.81 8.96 8.12
4.70
M (t-m) = 9.66 14.26
14.49 21.40
0.826 0.884
0.198 0.212
631 934
V (t) = 8.81 13.17
13.21 19.75
1.584 1.6070.408 0.423
0.130 0.189
0.027 0.058
1216 1256
62.21
0.408 1.250
Hence OK
Seismic/Wind case in X-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
a b c d a
a b c d a
Node 3L/C 8
= 48.828
= 15.569
= 0.103
83.127
= 1.5
25
16.18 6.69 16.12 6.63
4.70
M (t-m) = 15.20 12.21
22.80 18.31
1.300 0.757
0.319 0.181
1018 794
V (t) = 14.26 11.07
21.39 16.61
1.584 1.6070.408 0.423
0.211 0.159
0.074 0.040
1216 1256
62.21
0.408 1.250
Hence OK
R/F REQD 1215.87 1256.10
R/F PROVIDED 2543.40 2543.40Provided 12 dia @ 120 Provided 12 dia @ 120
Ast = 942 Ast = 942
Seismic/Wind case in Y-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
mm2/m mm2/m
a b c d a
a b c d a
F 4 0.600
0.380
0.6000.380
0.800
0.580
3.200
3.000
0.600
0.300
0.000
2.679
0.050
0.050
0.550
0.550
2.500
1.800
500
Wt. of footing (t) = 10.248 25
Wt. of soil over footing (t) = 35.072 10.0
45.320 14.8222
= 65.952 Node 14
= 0.367 Load Case 6
= 2.418
111.272
= 1.5
0
12.14 11.99 11.20 11.04
4.72
M (t-m) = 19.01 18.29
28.52 27.43
1.178 1.564
0.288 0.390
1265 1244
V (t) = 16.85 16.27
25.27 24.41
1.693 1.487
0.438 0.438
0.200 0.208
0.067 0.072
1513 1405
85.31
0.559 1.250
Hence OK
DESIGN OF FOOTING MARKED :- cl (m) =
cb (m) =
l (m) =b (m) =
l' (m) =
b' (m) =
L (m) =
B (m) =
D1 (m) =
D2 (m) =
Dp (m) =
Depth of foundation 'DF' below G.L (m) =
clear cover cx to R/F for forces about X-axis (m) =
clear cover cy to R/F for forces about Y-axis (m) =
effective depth 'd1' for forces about X-axis (m) =
effective depth 'd2' for forces about Y-axis (m) =
Unit wt. of Conc.'gc' (t/m3) =
Unit wt. of Soil. 'gs' (t/m3) =
Self wt. of footing and weight of soil on footing: fy (N/mm2) =
fck (N/mm2) =
Net Bearing Capacity 'qnet'
(t/m2) =
Footing Wt.+Soil Wt.= (P1 )(t) =
Gross Bearing Capacity 'qgross'
=(qnet+DF x gs )(t/m2) =
Static case :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=
d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
My
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
MZ
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
Node 14L/C 7
= 67.238
= 0.431
= 17.742
112.558
= 1.5
25
15.28 15.10 8.35 8.17
4.72
M (t-m) = 19.41 24.16
29.11 36.24
1.203 2.066
0.294 0.532
1293 1696
V (t) = 17.20 21.73
25.80 32.59
1.693 1.4870.438 0.438
0.205 0.278
0.070 0.136
1513 1592
85.31
0.559 1.250
Hence OK
Seismic/Wind case in X-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
a b c d a
a b c d a
Node 14L/C 10
= 67.029
= 8.091
= 2.335
112.349
= 1.5
25
13.84 10.47 12.93 9.56
4.72
M (t-m) = 22.45 18.54
33.68 27.81
1.392 1.585
0.344 0.396
1512 1263
V (t) = 20.04 16.50
30.06 24.74
1.693 1.4870.438 0.438
0.238 0.211
0.097 0.075
1513 1405
85.31
0.559 1.250
Hence OK
R/F REQD 1513.14 1696.07
R/F PROVIDED 3617.28 3391.20Provided 12 dia @ 100 Provided 12 dia @ 100
Ast = 1130 Ast = 1130
Seismic/Wind case in Y-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
mm2/m mm2/m
a b c d a
a b c d a
F 5 0.600
0.380
0.6000.380
0.800
0.580
2.900
2.900
0.600
0.300
0.000
2.679
0.050
0.050
0.550
0.550
2.500
1.800
500
Wt. of footing (t) = 9.026 25
Wt. of soil over footing (t) = 30.619 10.0
39.645 14.8222
= 52.712 Node 15
= 0.291 Load Case 6
= 3.251
92.357
= 1.5
0
11.85 11.71 10.25 10.11
4.71
M (t-m) = 14.55 13.15
21.82 19.72
0.902 1.124
0.217 0.273
953 872
V (t) = 13.02 12.01
19.52 18.01
1.615 1.574
0.434 0.421
0.171 0.163
0.048 0.043
1367 1330
73.41
0.481 1.250
Hence OK
DESIGN OF FOOTING MARKED :- cl (m) =
cb (m) =
l (m) =b (m) =
l' (m) =
b' (m) =
L (m) =
B (m) =
D1 (m) =
D2 (m) =
Dp (m) =
Depth of foundation 'DF' below G.L (m) =
clear cover cx to R/F for forces about X-axis (m) =
clear cover cy to R/F for forces about Y-axis (m) =
effective depth 'd1' for forces about X-axis (m) =
effective depth 'd2' for forces about Y-axis (m) =
Unit wt. of Conc.'gc' (t/m3) =
Unit wt. of Soil. 'gs' (t/m3) =
Self wt. of footing and weight of soil on footing: fy (N/mm2) =
fck (N/mm2) =
Net Bearing Capacity 'qnet'
(t/m2) =
Footing Wt.+Soil Wt.= (P1 )(t) =
Gross Bearing Capacity 'qgross'
=(qnet+DF x gs )(t/m2) =
Static case :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=
d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
My
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
(a+b)/2 (c+d)/2
DFD1D2
a
b
c
d a
cl
cbXX
Y
Y
MxMx
My
MZ
(b+d)/2
(a+c)/2
2
2
1 1
P
a b c d a
L
l'
bB
l
b'
Dp
Node 15L/C 7
= 55.572
= 0.239
= 18.317
95.217
= 1.5
25
15.89 15.77 6.87 6.76
4.71
M (t-m) = 15.31 19.03
22.96 28.54
0.949 1.627
0.229 0.407
1006 1299
V (t) = 13.70 17.72
20.55 26.57
1.615 1.5740.434 0.421
0.180 0.240
0.053 0.098
1367 1330
73.41
0.481 1.250
Hence OK
Seismic/Wind case in X-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
a b c d a
a b c d a
Node 15L/C 10
= 54.207
= 9.578
= 3.175
93.852
= 1.5
25
14.30 9.58 12.73 8.02
4.71
M (t-m) = 18.69 13.46
28.04 20.19
1.159 1.151
0.282 0.280
1242 894
V (t) = 16.94 12.29
25.40 18.44
1.615 1.5740.434 0.421
0.223 0.166
0.084 0.045
1367 1330
73.41
0.481 1.250
Hence OK
R/F REQD 1367.39 1330.21
R/F PROVIDED 2731.80 2731.80Provided 12 dia @ 120 Provided 12 dia @ 120
Ast = 942 Ast = 942
Seismic/Wind case in Y-direction :
P (t)
Mx (t-m)
My (t-m)
Total Load(PT = P + P1 ) (t) =
partial safety factor 'fs'
percent increase in qnet /qgross =
Pressure under footing(t/m2) = PT /(L x B) + Mx x 6 /(L x B2) + My x 6 /(B x L2)
Pressure due to Wt.of footing + Wt.of soil = P1 /(L x B)(t/m2) =
Taking average of pressure and calculating moment at the face of pedestal :About 1-1 : About 2-2 :
Mu = (fs x M)(t-m) =
ku (N/mm2) = Mu /(l' x d12) = Mu /(b' x d2
2) =
pt =
A st (mm2) = pt x l' x d1 /100 = pt x b' x d2/100 =
Taking average of pressure and calculating one-way shear force at "d" from the face of pedestal :
At 'd1' from 1-1: At 'd2' from 2-2:
Vu =(fs x V)(t) =
tv(N/mm2) =Vu/(Lx(D2-cx)+(L+b1')/2x{d1'-(D2-cx)} tv(N/mm2) =Vu/(Bx(D2-cy)+(BL+b2')/2x{d2'-(D2-cy)}
where b1'=[l'+2x{d1-(b'-b)/2}x(L-l')/(B-b')](m)= where b2'=[b'+2x{d2-(l'-l)/2}x(B-b')/(L-l')](m)=d1'=[(D2-cx)+{d1 -(D2-cx)}/{(B-b')/2}x{(B-b)/2-d1}]= d2'=[(D2-cy)+{d2 -(D2-cy)}/{(L-l')/2}x{(L-l)/2-d2}]=
tv(N/mm2) =
pt =
A st (mm2) = pt x Agross1 = pt x Agross2 =
Check for two-way Shear at "d/2" from the face of pedestal :
V(t) = {LxB-(l+d)x(b+d)}xqnet =
tv = Vu /(po x d) (N/mm2) where po = ( l+b+2d )
tv(N/mm2) = tc =(ksx0.25x(fck)1/2) (N/mm2) =
where ks=(1+E/F)but>1.0
mm2/m mm2/m
a b c d a
a b c d a