Design Data: Depth of Foundation = Depth of filling Safe Bearing capacity of soil Density of soil
ץ
Gross Bearing capacity of soil
Grade of concrete Density of concrete Reinforcement yield stress FOS Coefficient of friction between soil&conc Ф
Angle of repose
0.3
2.0
0.2 1.30
Larsen and Toubro
3
x
1.25
+
t/m2
t/m3 N/mm2 1.5
degrees
(SCF)
1.7
DOC.NO:
ALIF ENGINEERS AND PLANNERS
L&T/RIL/AEP/44PS4800/C/201
Design calculation LA Foundation
REV R0
Assume size of raft as follows L
=
1.30
m
B
=
1.30
m
t
=
0.2
m
=
2.0
m
=
0.70
Plinth level from FGL
=
0.30
m
Height of pedestal
=
2.1
m
=
1.86
tm
=
1.80
m
= x = = x = =
1.3 2.5 0.845 0.7 2.5 5.15 5.99
= ( x
1.3 0.7
ws Equip + str
= =
3.67 0.53
t t
0.53
t
Factored Total vertical load P Unfactored loads Check for eccentricity,bearing pressure &overturning Maximum soil pressure p1 (Considering unfactored loads)
= =
20.38 10.19
t t
15.29 10.19
t t
= =
6.03 8.57
+ t/m2<
2.54 17.15
= =
20.38
x
1.3 1.86
/
=
7.12
>
1.5
SAFE
=
15.29
0.6
=
42.47
x 0.216 >
1.5
SAFE
= =
15.29
x
1.3 2.10
/
=
4.73
>
1.5
SAFE
=
15.29
0.6
=
45.86
x 0.200 >
Depth of foundation from FGL
D
Pedestal size
Factored Longitudinal moment at base
pxp
M
Height of soil
mx
0.700
m
SCF 2.1
tm
Calculation of down thrust Weight of raft w1
Weight of pedestal w2
Total wr Weight of soil ws
Vertical load
F.O.S against overturning
F.O.S against sliding
F.O.S against overturning SCF Cond
F.O.S against sliding SCF Cond
Larsen and Toubro
4
x
1.3
x
0.2
x x
0.7 2
x
2.1
1.3 1.8
)-(1x x
0.7 1.7
t
t t
)
x x
(
1.5
SAFE
SAFE
2
2
)
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation LA Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Design of bottom pad Downward pressure to concrete
= =
0.2 0.5
= = = =
1.8 3.06 8.57 5.01
=
1.3
=
0.3
=
5.01
=
0.23
Factored maximum moment
=
0.23
Effective depth d
= =
0.34 145
Mu/bd2
=
Downward pressure due to earth Net upward pressure on pad
Maximum overhang
Maximum bending moment
x
2.5
x
1.7
-
3.56
2
0.70
x 2
0.3
x
2
t/m2
T/m2 t/m2
m
tm
tm mm 3319338 x
1000 =
0.16
N/mm2
% steel
=
0.036
%
Minimum % steel
=
0.12
%
Ast required
=
174.00
mm2
Assume diameter of bars as
=
10
mm
centre to centre spacing Ast provided Hence provide
10
= = mm @
200 392.6 200
mm mm2 mm c/c
145
Shear force
= = = =
0.3 0.155 5.01 0.78 1.55
Factored Shear force
Vu
=
Maximum shear stress
Tv
= 1000 = For pt '=
b factor = Permissible shear stress = t c =
Larsen and Toubro
5
0.11
at Top and Bottom
-
0.145
x
0.155
15540 x
145
m t/m t
N/mm2
0.27 12.86 0.38 N/mm2
2
OK
Check for shear:one way shear Maximum shear at a distance "d" from the face of the column Overhang from the face of the column
2
SAFE
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation LA Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Two way shear Critrical section at d/2 from face of pedestal = Perimeter for fractured pyramid = 2 * (B1+d+L1+d) = Area of fractured pyramid = (B1+d) * (L1+d) = Punching shear = V = (1-Pyramid Area/Area of footing) * P Max =
72.5 mm 3090 mm 0.714025 m2 2.895 Ton
Eff depth at critical section
145 mm
Shear stress = Vu / (Perimeter * Min Depth)
=
0.10 N/MM2
Allowable shear stress = 0.25 * SQRT(Fck)
=
1.37 N/MM2 HENCE SAFE
Design of Pedestal Pedestal size Vertical load on pedestal
= =
0.7 20.384
self weight of pedestal
=
Total vertical load
= =
2.1 x 2.57 22.96
t t
shear at plinth level
=
0.22
t
Moment at the base of the pedestal
0.22 =
0.45
m x
0.70
m
x 2.5
0.7
x
0.7
2.3
-
0.2
t
x ( tm
0.3
2
0.70 10 mm 0.2 1.3
m
Factored Total vertical load Factored Moment at the base of the pedestal
=
Larsen and Toubro
6
x =
1.3
m
45.91 0.91
t tm
@
200
mm c/c
@Bottom
)
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation LA Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
A. COMPRESSION WITH BENDING lef lef / D
= =
2.1 x 2 6.00 <
Total Moment
=
0.91
4.20 m 12 Short Column
+
0.00 =
0.91 Tm
Since Load is is very less only minimum reinforcement as per cl. 25.5.3(g) of IS 456 will be required. Concrete area required to resist direct vertical load=
Minimum Ast required
= =
45.91 x 10000 0.36 x 30.00 42512.04 mm2 0.8 % of the concrete area required to resist direct vertical load
= Provide longitudinal reinforcement of Ast Provided Spacing between reinforcement
0.80 12
nos
x 42512.04 = 100.00
12 dia
= =
1356.48 mm2 206.67 <
Design for lateral ties : Spacing of lateral ties shall be least of the following :I) Least lateral dimn of column = ii) 16 x dia of longitudinal reinf = iii) 48 x dia of transverse reinforcement=
700.00 mm 16.00 x 48.00 x
300.00
12.00 = 8.00 =
Privide 8mm ties at 190 mm c/c. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Larsen and Toubro
340.10 mm2
7
OK
192.00 mm 384.00 mm
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation BPI Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Maximum vertical load at PL
=
Normal 0.530
Ton
SCF 0.530
Ton
Maximum shear at PL
=
0.207
Ton
0.501
Ton
Maximum moment at PL
=
0.434
Tm
2.335
Tm
Back to Back of angles in elevation
=
0.400
m
Back to Back of angles in side view
=
0.400
m
CG of vert angle
=
1.41
cm
= =
2 0 11 1.7
m m t/m2 t/m3
= x =
11 2 17.15
= = = = =
30 2.5 500 2 0.6
=
6
Design Data: Depth of Foundation = Depth of filling Safe Bearing capacity of soil Density of soil
ץ
Gross Bearing capacity of soil
Grade of concrete Density of concrete Reinforcement yield stress FOS Coefficient of friction between soil&conc Angle of repose
Larsen and Toubro
Ф
8
x
1.25
+
t/m2
t/m3 N/mm2 1.5
degrees
(SCF)
1.7
DOC.NO:
ALIF ENGINEERS AND PLANNERS
L&T/RIL/AEP/44PS4800/C/201
Design calculation BPI Foundation
REV R0
0.3
2.0
0.2 1.30
Assume size of raft as follows L
=
1.30
m
B
=
1.30
m
t
=
0.2
m
=
2.0
m
=
0.60
Plinth level from FGL
=
0.30
m
Height of pedestal
=
2.1
m
=
1.82
tm
=
1.80
m
= x = = x = =
1.3 2.5 0.845 0.6 2.5 3.78 4.63
= ( x
1.3 0.6
ws Equip + str
= =
4.07 0.53
t t
0.53
t
Factored Total vertical load P Unfactored loads Check for eccentricity,bearing pressure &overturning Maximum soil pressure p1 (Considering unfactored loads)
= =
18.45 9.22
t t
13.84 9.22
t t
= =
5.46 7.94
+ 2 t/m <
2.49 17.15
= =
18.45
x
1.3 1.82
/
=
6.59
>
1.5
SAFE
Depth of foundation from FGL
D
Pedestal size
Factored Longitudinal moment at base
pxp
M
Height of soil
mx
0.600
m
SCF 5.23095 tm
Calculation of down thrust Weight of raft w1
Weight of pedestal w2
Total wr Weight of soil ws
Vertical load
F.O.S against overturning
Larsen and Toubro
9
x
1.3
x
0.2
x x
0.6 2
x
2.1
1.3 1.8
)-(1x x
0.6 1.7
t
t t
)
x x
(
SAFE 2
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation BPI Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
F.O.S against sliding
0.6
40.11
x 0.207 >
1.5
SAFE
= =
13.84
x
1.3 5.23
/
=
1.72
>
1.5
SAFE
=
13.84
0.6
=
16.57
x 0.501 >
= =
0.2 0.5
x
2.5
= = = =
1.8 3.06 7.94 4.38
x
1.7
-
3.56
=
1.3
2
0.60
=
0.35
=
4.38
x 2
0.35
=
0.27
Factored maximum moment
=
0.27
x
2
Effective depth d
= =
0.40 145
Mu/bd2
=
F.O.S against overturning SCF Cond
F.O.S against sliding SCF Cond
Design of bottom pad Downward pressure to concrete
Downward pressure due to earth Net upward pressure on pad
Maximum overhang
Maximum bending moment
=
13.84
=
1000
2
T/m2 t/m2
m
tm mm 3951219 x
% steel
=
0.043
%
Minimum % steel
=
0.12
%
Ast required
=
174.00
mm2
Assume diameter of bars as
=
10
mm
Larsen and Toubro
10
10
145
2
2
N/mm
200 392.6 200
2
tm
0.19
= = mm @
SAFE
t/m
=
centre to centre spacing Ast provided Hence provide
1.5
mm 2 mm mm c/c
OK at Top and Bottom
2
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation BPI Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Check for shear:one way shear Maximum shear at a distance "d" from the face of the column Overhang from the face of the column Shear force
= = = =
0.35 0.205 4.38 0.90 1.80
Factored Shear force
Vu
=
Maximum shear stress
Tv
=
For pt '=
x
0.205
17974 x
145
t
0.12
b factor = Permissible shear stress = t c =
0.145
t/m
1000 =
m
N/mm2
0.27 12.86 0.38 N/mm2
SAFE
Two way shear Critrical section at d/2 from face of pedestal = Perimeter for fractured pyramid = 2 * (B1+d+L1+d) = Area of fractured pyramid = (B1+d) * (L1+d) = Punching shear = V = (1-Pyramid Area/Area of footing) * P Max =
72.5 mm 2690 mm 0.555025 m2 2.944 Ton
Eff depth at critical section
145 mm
Shear stress = Vu / (Perimeter * Min Depth)
=
0.11 N/MM2
Allowable shear stress = 0.25 * SQRT(Fck)
=
1.37 N/MM2 HENCE SAFE
Design of Pedestal Pedestal size Vertical load on pedestal
= =
0.6 18.450
self weight of pedestal
=
Total vertical load
= =
2.1 x 1.89 20.34
t t
shear at plinth level
=
0.21
t
Moment at the base of the pedestal
0.21 =
0.43
m x
0.60
m
x 2.5
0.6
x
0.6
2.3
-
0.2
t
x ( tm
0.3
2
0.60 10 mm 0.2 1.3
Larsen and Toubro
m 11
x
1.3
m
@
200
mm c/c
@Bottom
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation BPI Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Factored Total vertical load Factored Moment at the base of the pedestal
=
40.68 0.87
=
t tm
A. COMPRESSION WITH BENDING lef lef / D
= =
2.1 x 2 7.00 <
Total Moment
=
0.87
4.20 m 12 Short Column
+
0.00 =
0.87 Tm
Since Load is is very less only minimum reinforcement as per cl. 25.5.3(g) of IS 456 will be required. Concrete area required to resist direct vertical load=
Minimum Ast required
= =
40.68 x 10000 0.36 x 30.00 37665.93 mm2 0.8 % of the concrete area required to resist direct vertical load
= Provide longitudinal reinforcement of Ast Provided Spacing between reinforcement
0.80 12
= =
Design for lateral ties : Spacing of lateral ties shall be least of the following :I) Least lateral dimn of column = ii) 16 x dia of longitudinal reinf = iii) 48 x dia of transverse reinforcement=
nos
x 37665.93 = 100.00
12 dia 1356.48 mm2 173.33 <
600.00 mm 16.00 x 48.00 x
300.00
12.00 = 8.00 =
Privide 8mm ties at 190 mm c/c. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Larsen and Toubro
301.33 mm2
12
OK
192.00 mm 384.00 mm
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation BPI Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Larsen and Toubro
13
44PS4800/C/201
V R0
Larsen and Toubro
14
44PS4800/C/201
V R0
)
Larsen and Toubro
15
44PS4800/C/201
V R0
Larsen and Toubro
16
44PS4800/C/201
V R0
)
Larsen and Toubro
17
44PS4800/C/201
V R0
Larsen and Toubro
18
44PS4800/C/201
V R0
Larsen and Toubro
19
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation CT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Maximum vertical load at PL
=
Normal 1.010
Ton
SCF 1.010
Ton
Maximum shear at PL
=
0.246
Ton
0.175
Ton
Maximum moment at PL
=
0.514
Tm
0.823
Tm
Back to Back of angles in elevation
=
0.700
m
Back to Back of angles in side view
=
0.700
m
CG of vert angle
=
1.41
cm
= =
2 0 11 1.7
m m t/m2 t/m3
= x =
11 2 17.15
= = = = =
30 2.5 500 2 0.6
=
6
Design Data: Depth of Foundation = Depth of filling Safe Bearing capacity of soil Density of soil
ץ
Gross Bearing capacity of soil
Grade of concrete Density of concrete Reinforcement yield stress FOS Coefficient of friction between soil&conc Ф
Angle of repose
0.3
2.0
0.2 1.30 Larsen and Toubro
20
x
1.25
+
t/m2
t/m3 N/mm2 1.5
degrees
(SCF)
1.7
DOC.NO:
ALIF ENGINEERS AND PLANNERS
L&T/RIL/AEP/44PS4800/C/201
Design calculation CT Foundation
REV R0
Assume size of raft as follows L
=
1.30
m
B
=
1.30
m
t
=
0.2
m
=
2.0
m
=
0.850
Plinth level from FGL
=
0.30
m
Height of pedestal
=
2.1
m
=
2.16
tm
=
1.80
m
= x = = x = =
1.3 2.5 0.845 0.85 2.5 7.59 8.43
= ( x
1.3 0.85
ws Equip + str
= =
2.96 1.01
t t
1.01
t
Factored Total vertical load P Unfactored loads Check for eccentricity,bearing pressure &overturning Maximum soil pressure p1 (Considering unfactored loads)
= =
24.80 12.40
t t
18.60 12.40
t t
= =
7.34 10.29
+ t/m2<
2.95 17.15
= =
24.80
x
1.3 2.16
/
=
7.47
>
1.5
SAFE
=
18.60
0.6
=
45.37
x 0.246 >
1.5
SAFE
= =
18.60
x
1.3 1.84
/
=
6.58
>
1.5
SAFE
=
18.60
0.6
=
63.78
x 0.175 >
Depth of foundation from FGL
D
Pedestal size
Factored Longitudinal moment at base
pxp
M
Height of soil
mx
0.850
m
SCF 1.83825 tm
Calculation of down thrust Weight of raft w1
Weight of pedestal w2
Total wr Weight of soil ws
Vertical load
F.O.S against overturning
F.O.S against sliding
F.O.S against overturning SCF Cond
F.O.S against sliding SCF Cond
Larsen and Toubro
21
x
1.3
x
0.2
x x
0.85 2
x
2.1
1.3 1.8
)-(1x x
0.85 1.7
t
t t
)
x x
(
1.5
SAFE
SAFE
2
2
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation CT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Design of bottom pad Downward pressure to concrete
= =
0.2 0.5
= = = =
1.8 3.06 10.29 6.73
=
1.3
=
0.225
=
6.73
=
0.17
Factored maximum moment
=
0.17
Effective depth d
= =
0.26 145
Mu/bd2
=
Downward pressure due to earth Net upward pressure on pad
Maximum overhang
Maximum bending moment
x
2.5
x
1.7
-
3.56
2
0.85
x 2
0.225
x
2
t/m2
2
T/m
2
t/m
m
tm
tm mm 2505731 x
1000 0.12
N/mm
% steel
=
0.027
%
Minimum % steel
=
0.12
%
Ast required
=
174.00
mm2
Assume diameter of bars as
=
10
mm
10
= = mm @
200 392.6 200
145
mm mm2 mm c/c
OK at Top and Bottom
Check for shear:one way shear Maximum shear at a distance "d" from the face of the column Overhang from the face of the column Shear force
= = = =
0.225 0.08 6.73 0.54 1.08
Factored Shear force
Vu
=
Maximum shear stress
Tv
= 1000 = For pt '=
b factor = Permissible shear stress = t c = Larsen and Toubro
22
0.07
2
2
=
centre to centre spacing Ast provided Hence provide
2
-
0.145
x
0.08
10764 x
145
m t/m t
N/mm2
0.27 12.86 0.38 N/mm2
SAFE
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation CT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Two way shear Critrical section at d/2 from face of pedestal = Perimeter for fractured pyramid = 2 * (B1+d+L1+d) = Area of fractured pyramid = (B1+d) * (L1+d) = Punching shear = V = (1-Pyramid Area/Area of footing) * P Max =
72.5 mm 3690 mm 0.990025 m2 2.786 Ton
Eff depth at critical section
145 mm
Shear stress = Vu / (Perimeter * Min Depth)
=
0.08 N/MM2
Allowable shear stress = 0.25 * SQRT(Fck)
=
1.37 N/MM2 HENCE SAFE
Design of Pedestal Pedestal size Vertical load on pedestal
= =
0.85 24.804
self weight of pedestal
=
Total vertical load
= =
2.1 x 3.79 28.60
t t
shear at plinth level
=
0.25
t
Moment at the base of the pedestal
0.25 =
0.52
m x
0.85
m
x 2.5
0.9
x
0.9
2.3
-
0.2
t
x ( tm
0.3
2
0.85 10 mm 0.2 1.3
Factored Total vertical load Factored Moment at the base of the pedestal
Larsen and Toubro
m
x =
=
23
1.3
m
57.19 1.03
t tm
@
200
mm c/c
@Bottom
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation CT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
A. COMPRESSION WITH BENDING lef lef / D
= =
2.1 x 2 4.94 <
Total Moment
=
1.03
4.20 m 12 Short Column
+
0.00 =
1.03 Tm
Since Load is is very less only minimum reinforcement as per cl. 25.5.3(g) of IS 456 will be required. Concrete area required to resist direct vertical load=
Minimum Ast required
= =
57.19 x 10000 0.36 x 30.00 52956.90 mm2 0.8 % of the concrete area required to resist direct vertical load
= Provide longitudinal reinforcement of Ast Provided Spacing between reinforcement
0.80 12
= =
Design for lateral ties : Spacing of lateral ties shall be least of the following :I) Least lateral dimn of column = ii) 16 x dia of longitudinal reinf = iii) 48 x dia of transverse reinforcement=
nos
x 52956.90 = 100.00
12 dia 1356.48 mm2 256.67 <
850.00 mm 16.00 x 48.00 x
300.00
12.00 = 8.00 =
Privide 8mm ties at 190 mm c/c. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Larsen and Toubro
423.66 mm2
24
OK
192.00 mm 384.00 mm
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation CT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Larsen and Toubro
25
44PS4800/C/201
V R0
Larsen and Toubro
26
44PS4800/C/201
V R0
)
Larsen and Toubro
27
44PS4800/C/201
V R0
Larsen and Toubro
28
44PS4800/C/201
V R0
)
Larsen and Toubro
29
44PS4800/C/201
V R0
Larsen and Toubro
30
44PS4800/C/201
V R0
Larsen and Toubro
31
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation PT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Maximum vertical load at PL
=
Normal 0.930
Ton
SCF 0.930
Ton
Maximum shear at PL
=
0.228
Ton
0.175
Ton
Maximum moment at PL
=
0.493
Tm
0.823
Tm
Back to Back of angles in elevation
=
0.500
m
Back to Back of angles in side view
=
0.500
m
CG of vert angle
=
1.41
cm
= =
2 0 11 1.7
m m t/m2 t/m3
= x =
11 2 17.15
= = = = =
30 2.5 500 2 0.6
=
6
Design Data: Depth of Foundation = Depth of filling Safe Bearing capacity of soil Density of soil
ץ
Gross Bearing capacity of soil
Grade of concrete Density of concrete Reinforcement yield stress FOS Coefficient of friction between soil&conc Ф
Angle of repose
0.3
2.0
0.2 1.30 Larsen and Toubro
32
x
1.25
+
t/m2
t/m3 N/mm2 1.5
degrees
(SCF)
1.7
DOC.NO:
ALIF ENGINEERS AND PLANNERS
L&T/RIL/AEP/44PS4800/C/201
Design calculation PT Foundation
REV R0
Assume size of raft as follows L
=
1.30
m
B
=
1.30
m
t
=
0.2
m
=
2.0
m
=
0.70
Plinth level from FGL
=
0.30
m
Height of pedestal
=
2.1
m
=
2.03
tm
=
1.80
m
= x = = x = =
1.3 2.5 0.845 0.7 2.5 5.15 5.99
= ( x
1.3 0.7
ws Equip + str
= =
3.67 0.93
t t
0.93
t
Factored Total vertical load P Unfactored loads Check for eccentricity,bearing pressure &overturning Maximum soil pressure p1 (Considering unfactored loads)
= =
21.18 10.59
t t
15.89 10.59
t t
= =
6.27 9.05
+ t/m2<
2.78 17.15
= =
21.18
x
1.3 2.03
/
=
6.77
>
1.5
SAFE
=
15.89
0.6
=
41.81
x 0.228 >
1.5
SAFE
= =
15.89
x
1.3 1.84
/
=
5.62
>
1.5
SAFE
=
15.89
0.6
=
54.47
x 0.175 >
Depth of foundation from FGL
D
Pedestal size
Factored Longitudinal moment at base
pxp
M
Height of soil
mx
0.700
m
SCF 1.83825 tm
Calculation of down thrust Weight of raft w1
Weight of pedestal w2
Total wr Weight of soil ws
Vertical load
F.O.S against overturning
F.O.S against sliding
F.O.S against overturning SCF Cond
F.O.S against sliding SCF Cond
Larsen and Toubro
33
x
1.3
x
0.2
x x
0.7 2
x
2.1
1.3 1.8
)-(1x x
0.7 1.7
t
t t
)
x x
(
1.5
SAFE
SAFE
2
2
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation PT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Design of bottom pad Downward pressure to concrete
= =
0.2 0.5
= = = =
1.8 3.06 9.05 5.49
=
1.3
=
0.3
=
5.49
=
0.25
Factored maximum moment
=
0.25
Effective depth d
= =
0.37 145
Mu/bd2
=
Downward pressure due to earth Net upward pressure on pad
Maximum overhang
Maximum bending moment
x
2.5
x
1.7
-
3.56
2
0.70
x 2
0.3
x
2
t/m2
2
T/m
2
t/m
m
tm
tm mm 3632673 x
1000 0.17
N/mm
% steel
=
0.040
%
Minimum % steel
=
0.12
%
Ast required
=
174.00
mm2
Assume diameter of bars as
=
10
mm
10
= = mm @
200 392.6 200
145
mm mm2 mm c/c
OK at Top and Bottom
Check for shear:one way shear Maximum shear at a distance "d" from the face of the column Overhang from the face of the column Shear force
= = = =
0.3 0.155 5.49 0.85 1.70
Factored Shear force
Vu
=
Maximum shear stress
Tv
= 1000 = For pt '=
b factor = Permissible shear stress = t c = Larsen and Toubro
34
0.12
2
2
=
centre to centre spacing Ast provided Hence provide
2
-
0.145
x
0.155
17007 x
145
m t/m t
N/mm2
0.27 12.86 0.38 N/mm2
SAFE
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation PT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
Two way shear Critrical section at d/2 from face of pedestal = Perimeter for fractured pyramid = 2 * (B1+d+L1+d) = Area of fractured pyramid = (B1+d) * (L1+d) = Punching shear = V = (1-Pyramid Area/Area of footing) * P Max = Eff depth at critical section Shear stress = Vu / (Perimeter * Min Depth)
=
Allowable shear stress = 0.25 * SQRT(Fck)
=
72.5 mm 3090 mm 0.714025 m2 3.168 Ton 145 mm 0.11 N/MM2 1.37 N/MM2 HENCE SAFE
Design of Pedestal Pedestal size Vertical load on pedestal
= =
0.7 21.184
self weight of pedestal
=
Total vertical load
= =
2.1 x 2.57 23.76
t t
shear at plinth level
=
0.23
t
=
0.23 0.48
x ( tm
Moment at the base of the pedestal
m x
0.70
m
x 2.5
0.7
x
0.7
2.3
-
0.2
t
0.3
2
0.70 10 mm 0.2 1.3
Factored Total vertical load Factored Moment at the base of the pedestal
Larsen and Toubro
m
x =
=
35
1.3
m
47.51 0.96
t tm
@
200
mm c/c
@Bottom
DOC.NO:
ALIF ENGINEERS AND PLANNERS
Design calculation PT Foundation
L&T/RIL/AEP/44PS4800/C/201 REV R0
A. COMPRESSION WITH BENDING lef = 2.1 x 2 4.20 m lef / D = 6.00 < 12 Short Column Total Moment = 0.96 + 0.00 = 0.96 Tm Since Load is is very less only minimum reinforcement as per cl. 25.5.3(g) of IS 456 will be required. Concrete area required to resist direct vertical load=
Minimum Ast required
= =
47.51 x 10000 0.36 x 30.00 43993.52 mm2 0.8 % of the concrete area required to resist direct vertical load
= Provide longitudinal reinforcement of 12 Ast Provided = Spacing between reinforcement = Design for lateral ties : Spacing of lateral ties shall be least of the following :I) Least lateral dimn of column = ii) 16 x dia of longitudinal reinf = iii) 48 x dia of transverse reinforcement=
0.80 nos
x 43993.52 = 100.00
12 dia 1356.48 mm2 206.67 <
700.00 mm 16.00 x 48.00 x
300.00
12.00 = 8.00 =
Privide 8mm ties at 190 mm c/c. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
