Design report

On
Footing design of Ward office Building
Ward no. 6, Shuklaphanta Municipality
Jhalari, kanchanpur

Submitted By:

Date: 5/9/2021
 1.1. Mat Foundation

Mat footing is designed assuming that it is rigid. The Vertical loads coming on the footing from
columns are extracted from SAP2000 analysis result for load combination (DL+LL). The bearing
capacity of Soil is assumed as 300 KN/m2 as per the soil report. The following steps constitute
the footing design:

Source: Soil Report of the construction site

 Joint Grid FZ (KN) x y Mx (KNm) My (KNm)
66 A1 507 0.00 0.00 0 0
70 A2 497 4.00 0.00 1986 0
74 A3 362 8.60 0.00 3109 0
65 B1 368 0.00 4.00 0 1470
69 B2 885 4.00 4.00 3540 3540
73 B3 654 8.60 4.00 5624 2616
64 C1 377 0.00 8.50 0 3200
68 C2 894 4.00 8.50 3576 7599
72 C3 654 8.60 8.50 5624 5559
63 D1 215 0.00 12.50 0 2681
67 D2 506 4.00 12.50 2022 6319
71 D3 362 8.60 12.50 3109 4519
Total 6,277.50 28,590.60 37,503.00

Total Column Reactions =

Xarea = 4.30 m Xload = 4.55 m
Yarea = 6.25 m Yload = 5.97 m
ex = 0.25 m
ey = -0.28 m
3
Ix = b x d /12 = 4,861.777 m4
3
Iy = d x b/12 = 3,387.415 m4
2
A= 107.50 m
P = 6,278 KN
Mx = P x ey = -1731.38 KNm
My = P x ex = 1597.35 KNm
2
SBC = 300 KN/m
2
P/A = 58.40 KN/m
3
My/Iy = 0.47 KN/m
3
Mx/Ix = -0.36 KN/m
2
Stress Calculations in KN/m :
σ = P/A ± My/Iy * X ± Mx/Ix * Y
Joint Grid X Y σ Remarks
66 A1 -4.30 -6.25 58.59 OK
70 A2 -0.30 -6.25 60.48 OK
74 A3 4.30 -6.25 62.65 OK
65 B1 -4.30 -2.25 57.17 OK
69 B2 -0.30 -2.25 59.06 OK
73 B3 4.30 -2.25 61.22 OK
64 C1 -4.30 2.25 55.57 OK
68 C2 -0.30 2.25 57.45 OK
72 C3 4.30 2.25 59.62 OK
63 D1 -4.30 6.25 54.14 OK
67 D2 -0.30 6.25 56.03 OK
71 D3 4.30 6.25 58.20 OK
Y: 9.42E+16
 Joint Grid FZ (KN) x y Mx (KNm) My (KNm)
66 A1 507 0.00 0.00 0 0
70 A2 497 4.00 0.00 1986 0
74 A3 362 8.60 0.00 3109 0
65 B1 368 0.00 4.00 0 1470
69 B2 885 4.00 4.00 3540 3540
73 B3 654 8.60 4.00 5624 2616
64 C1 377 0.00 8.50 0 3200
68 C2 894 4.00 8.50 3576 7599
72 C3 654 8.60 8.50 5624 5559
63 D1 215 0.00 12.50 0 2681
67 D2 506 4.00 12.50 2022 6319
71 D3 362 8.60 12.50 3109 4519
T otal 6, 277. 50 28,590.60 37,503.00

To tal Co lumn Reactions =

Xarea = 4.30 m Xload = 4. 55 m
Yarea = 6.25 m Yload = 5. 97 m
ex = 0.25 m
ey = -0.28 m
3
Ix = b x d /12 = 4,861.777 m4
3
Iy = d x b/12 = 3,387.415 m4
2
A = 107.50 m
P = 6, 278 KN
Mx = P x ey = -1731.38 KNm
My = P x ex = 1597.35 KNm
2
SBC = 300 KN/m
2
P /A = 58.40 KN/m
3
My/Iy = 0.47 KN/m
3
Mx/Ix = -0.36 KN/m
2
Stress Calculatio ns in KN/m :
σ = P/A ± My/Iy * X ± Mx/Ix * Y
Joint Grid X Y σ Remarks
66 A1 -4.30 -6.25 58.59 OK
70 A2 -0.30 -6.25 60.48 OK
74 A3 4.30 -6.25 62.65 OK
65 B1 -4.30 -2.25 57.17 OK
69 B2 -0.30 -2.25 59.06 OK
73 B3 4.30 -2.25 61.22 OK
64 C1 -4.30 2.25 55.57 OK
68 C2 -0.30 2.25 57.45 OK
72 C3 4.30 2.25 59.62 OK
63 D1 -4.30 6.25 54.14 OK
67 D2 -0.30 6.25 56.03 OK
71 D3 4.30 6.25 58.20 OK
Y: 9.42E+16

2
Average Stress alo ng grids in (KN/m )
A-A 60.57
B-B 59.15
C-C 57.55
D-D 42.09
1-1 56.37
2-2 46.60
3-3 60.42

Bending mome nt calculations in KNm/m

Along grids
1-2 2-3
l= 4.00 4.60
A-A 145.38 192.26
B-B 141.96 187.74
C-C 138.11 182.65
D-D 101.02 133.60

A-B B-C C-D

l= 4.00 4.50 4.00
1-1 135.28 171.22 135.28
2-2 111.85 141.56 111.85
3-3 145.02 183.53 145.02

Depth fro m Mo ment = 268.85 mm

Facto r of Safety = 1.50
She ar Che ck:
Shear strength of concrete t'c for M20 grade =0.25sqrt(fck) = 1.12 N/mm2

1. For edge co lumn

bo = d+2c = d +1500
column load = 654 KN
Vu = 981000 N
a= 1
b= 1500
c= -877433.0744 Coeff of d
d= 449.97 mm value of 2c

2. For face column

bo = 2d+3c = 2d +1950
column load = 507 KN
Vu = 760500
a = 2
b = 1950
c = -680211.8788 Coeff of d
d = 272.61 mm value of 3c
 2
Average Stress alo ng grids in (KN/m )
A-A 60.57
B-B 59.15
C-C 57.55
D-D 42.09
1-1 56.37
2-2 46.60
3-3 60.42

Be nding mome nt calculations in KNm/m

Along grids
1-2 2-3
l= 4.00 4.60
A-A 145.38 192.26
B-B 141.96 187.74
C-C 138.11 182.65
D-D 101.02 133.60

A-B B-C C-D

l= 4.00 4.50 4.00
1-1 135.28 171.22 135.28
2-2 111.85 141.56 111.85
3-3 145.02 183.53 145.02

Depth fro m Mo ment = 268.85 mm

Facto r o f Safety = 1.50
She ar Che ck:
Shear strength of concrete t'c for M20 grade =0.25sqrt(fck) = 1.12 N/mm2

1. Fo r edge co lumn
bo = d+2c = d +1500
column load = 654 KN
Vu = 981000 N
a= 1
b= 1500
c= -877433.0744 Coeff of d
d= 449.97 mm value of 2c

2. Fo r face co lumn
bo = 2d+3c = 2d +1950
column load = 507 KN
Vu = 760500
a = 2
b = 1950
c = -680211.8788 Coeff of d
d = 272.61 mm value of 3c

3. For central column

bo = 4d+4c = 4d + 1800
column load = 743 KN
Vu = 1113750 N
a= 4 Coeff of d
b= 1800 value of 4c
c= -1113750

d= 348.64 mm
d= 449.97 mm
499.97 mm
Provide D= 750 mm
2
Area of Steel Reinforcements Required in mm
2
Minmum Area of Steel Required in mm =0.15*1000*d/100 = 1125.00

Dia of bar Spacing

Grid Max BM Ast required Ast Provided Remarks
Provided Provided
A-A 192.262 646.32 16 150 1340.41 OK
B-B 187.740 630.76 16 150 1340.41 OK
C-C 182.654 613.28 16 150 1340.41 OK
D-D 133.599 445.85 16 150 1340.41 OK
1-1 171.217 574.06 16 150 1340.41 OK
2-2 141.557 472.87 16 150 1340.41 OK
3-3 183.535 616.31 16 150 1340.41 OK

Summary: Mat footing depth 750mm including 50mm cover

Rebar: 16mm @ 150mm C/C top and bottom both ways