DESIGN OF STRAP
1.
General Data
Edge column Load, Service only (LL+DL)
Column size
Projection of pad edge from left column
Spacing
Interior column Load, Service only (LL+DL)
Column size
FOS
Unit Weight of Beam
Soil SBC
Concrete grade
Steel Grade
Clear Cover bottom of slab
% of foundation weight for vertical load
Total Area of footing needed
2.
Size of footing:
Load Center measured from Right Column center
3.
Thickness of footing From Bending Criteria
Net upward pressure
Beam Width
Mumax
Effective Depth of Footing
4.
Reinforcement in Slab Along Y direction
Overall Depth of slab
Effective depth of Slab
Length of Cantiliver projection of Larger slab
Maximum Udl in unit Slab
Maximum Bending moment
Ast required
Diameter of Bar to be used
Spacing Provided
Provided Spacing
Ast provided
Hence provide 12 mm dia bar @ 150 mm c/c parallel to length of footing ( || to Y)
5.
Reinforcement in Slab Along X direction
Assuming minimum reinforcement
Area of Steel to be provided
Diameter of Bar to be used
Spacing required
Provided Spacing
Ast provided
Hence provide 12 mm dia bar @ 175 mm c/c parallel to length of footing ( || to X)
6.
CHECK FOR ONE WAY SHEAR :
One way shear at critical section L1- L1
Distance of critical sec. from edge of Beam or Column
Maximum Shear stress right Pad slab
% of Reinforcement provided
Allowable Shear Stress
tv < tc hence O.K.
7.
Design of footing Beam
Upward UDL pressure for Beam Design
Diameter of Bars used in Beam
Width of Beam
Overall Depth of beam
Effective depth of Beam
Bending Moment coming near Left column
MuLim of Beam
So Design Beam As Singly Re
Top Reinforcement required
Total no of Longitudinal Reinforcement
Total no of Longitudinal Reinforcement provided
Bottom beam Reinforcement required
Total no of Longitudinal Reinforcement provided
Bending Moment coming near Left column
MuLim of Beam
So Design As Doubly reinfo
Top Reinforcement required
Total no of Longitudinal Reinforcement
50% to be provided at top
8.
Shear Design For Beam
Maximum Shear Force Come to be in interior col left face
Shear Stress
% of Steel Provided in the Beam
As Per Is 456: Allowable shear Stress
Here
Diameter of Shear Reinforcement
No of Legs used
spacing of Stirrups
spacing of Stirrups Provided
Hence Provide 2 legged 12 Dia. Stirrups@100mm c/c near The column
9.
Curtailment of Beam rebars
Position of Zero BM from right column center
BENDING MOMENT AND SHEAR F
693
BENDING MOMENT AND SHEAR F
693
307.6
263.4
95156.46
0 28
-2.07
0.00
1.00
194.98
190.12
183.44
199.22
198.01219.1
174.9
95
2.00
3.00
4.00
-272
-599
-972.6
-972.6
IGN OF STRAP BEAM
=
=
=
=
200
300
0.15
3.84
861
500
1.5
25
KN
mm
m
m
KN
mm
150
kN/m2
20
N/mm2
=
=
=
=
500
50
10%
7.78
N/mm2
mm
0.72
L1
B
B
L2
=
=
=
=
2.142
0.901
0.901
6.499
m
m
m
m
qu
Bb
Mu,max
df
=
=
=
=
204.55
450.00
5.20
44.19
=
=
D
d
=
500
=
444
=
0.23
=
204.55
=
5.20
Ast
=
27.0
=
12.0
S
=
4196.2
Sp
=
150.0
Ap
=
754
of footing ( || to Y) at bottom
0.120
kN/m3
m2
kN/m2
mm
kNm/m
mm
mm
mm
m
kN/m
kNm
mm2
mm
mm
mm
mm2
0.90
6.50
=
600
=
12.0
S
=
188.5
Sp
=
175.0
Ap
=
646
of footing ( || to X) at bottom
d
tv
=
=
=
tc
444
-0.11
0.170
0.30
mm2
mm
mm
mm
mm2
mm
N/mm2
%
N/mm2
rd
Wb
Db
db
=
=
=
=
=
184.2
25
450
600
547.5
mm
mm
mm
mm
kN/m
=
=
307.57
358.81
kNm
kNM
n Beam As Singly Reinforced Beam
Asttop
Astbott
=
=
=
1602
3
1602
mm2
Nos
mm2
=
=
-262
-1
mm2
Nos
=
729.48
=
358.81
ign As Doubly reinforced Beam
=
Err:502
Astbott
=
Err:502
=
Err:502
Asttop
=
Err:502
Sp
=
=
=
=
>
=
=
=
=
=
=
647
2.627
0.65
0.53
tc
516.6
12
2
226.2
104
100
5.11
tv
tc
tv
Vus
Asv
column
0.5 f ck
fy
kNm
kNM
mm2
Nos
mm2
Nos
kN
N/mm2
%
N/mm2
Need Shear Reinforcement
kN
mm
Nos
mm2
mm
MENT AND SHEAR FORCE DIAGRAM
693
Ast
4.6 M u
f ck bd 2
bd
MENT AND SHEAR FORCE DIAGRAM
693
4.00
-599
-972.6
-972.6
5.00
6.00
7.00 0.0
8.00
1
0.000
0
2
0.150
28
3
2.142
94.66
0.150
-272
BMD
6
3.990
-599
7.239
0
2.07
-199.2
972.63
Max Shear Force 1
Max Shear Force 2
0<=
5
3.990
693
1.48
Left Col support BM
Max BM at zero shear
Right Col SuppBM
BMD
4
0.741
94.66
=
=
0.150
x
0
0.02
0.03
0.05
0.06
0.08
0.09
0.11
0.12
0.14
0.15
647.3
245
Near right column
Near left column
y
0.00
-0.02
-0.08
-0.19
-0.33
-0.52
-0.75
-1.02
-1.33
-1.68
-2.07
0.150 <=
x
0.00
0.100
0.199
0.299
0.398
0.498
0.598
0.697
0.797
0.896
0.996
1.096
kN
kN
0.000
0.015
0.030
0.045
0.060
0.075
0.090
0.105
0.120
0.135
0.150
0.0
0.0
-0.1
-0.2
-0.3
-0.5
-0.7
-1.0
-1.3
-1.7
-2.1
0.15
0.25
0.35
0.45
0.55
0.65
0.75
0.85
0.95
1.05
1.15
1.25
-2.1
24.1
48.5
71.1
91.8
110.7
127.8
143.0
156.5
168.0
177.8
185.7
2.142
y
-2.07
24.14
48.53
71.08
91.81
110.72
127.79
143.04
156.46
168.05
177.81
185.75
BMD
BMD
1.195
1.295
1.394
1.494
1.594
1.693
1.793
1.892
1.992
2.142 <=
x
0
-0.467
-0.934
-1.401
0.741 <=
1.35
1.44
1.54
1.64
1.74
1.84
1.94
2.04
2.14
191.9
196.1
198.6
199.2
198.0
195.0
190.1
183.4
174.9
2.14
1.67
1.21
0.74
174.9
219.1
263.4
307.6
0.741
1.066
1.391
1.715
2.040
2.365
2.690
3.015
3.340
3.665
3.990
307.565
267.1
207.1
127.8
28.9
-89.4
-227.1
-384.3
-561.0
-757.1
-972.6
3.990
4.315
4.640
4.965
5.290
5.615
5.940
6.265
6.589
6.914
7.239
-972.6
-787.8
-622.5
-476.6
-350.1
-243.2
-155.6
-87.5
-38.9
-9.7
0.0
307.6
-972.6
3.990
x
0
0.325
0.650
0.975
1.300
1.625
1.950
2.275
2.599
2.924
3.249
BMD
191.86
196.14
198.59
199.22
198.01
194.98
190.12
183.44
174.92
0.741
y
174.92
219.14
263.35
307.57
3.990 <=
y
307.57
267.08
207.15
127.76
28.92
-89.38
-227.12
-384.32
-560.97
-757.08
-972.63
7.239
x
0
0.325
0.650
0.975
1.300
1.625
1.950
2.275
2.599
2.924
3.249
y
-972.633
-787.83
-622.49
-476.59
-350.15
-243.16
-155.62
-87.54
-38.91
-9.73
0.00
300
1292
184.24636
Position of
5.114
Mulim
.138fckbd^2
.133fckbd^3
for fe415
for fe500
