%pt req (from SP-16)= Min steel= Astreq (sq.mm)/m width = use bar dia (mm) = Area=ast=
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
0.228 page no 49 0.12 % 1211.49 mm2 12 1.13 mm2
Spacing of reinforcement required
93.35 mm
Provide reinforcement=
90.00 mm
Provide reinforcement= Area of steel provided=Ast= %pt(provided)=
Y12-90c/c 1256.64 mm2 0.236
Reinforcement steel at top(x-direction) Max BM(T-m)/m width=
3.50 t-m
Footing thickness, D(mm)=
600 mm
clear cover to footing (mm)=
50 mm
Assume bar dia(mm)=
20 mm
effective depth available(mm),d=
520 mm
Mu/bd2 (N/sq.mm) =
0.13 mm2
%pt req (from SP-16)= Min steel= Astreq (sq.mm)/m width = use bar dia (mm) = Area
0.048 0.12 % 624.000 20 mm 3.14 mm2
Spacing of reinforcement required(mm)=
503.46 mm
Provide reinforcement=
200.00 mm
PROJECT:
DESIGN OF COMBINE FOOTING
TITLE :
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
Provide reinforcement= Area of steel provided=Ast= %pt(provided)=
Y20-200c/c 1570.80 mm2 0.302 % 0.40 N/mm2
permissible shear strength,tcav(N/sq.mm)=
Check for one-way shear(X-direction) Shear is checked at effective depth 'd' from the face of pedestal The critical shear at 'd' from pedestal face
520 mm
Efeective depth of footing=
1800 mm
Pedestal width (mm) = Footing projection beyond face of pedestal =
788 mm
length beyond d=
268 mm
SF (Factored)
19.147 t
Shear stress(factored) ,tvu
0.243 N/sq.mm 0.40 N/sq.mm
Permissible shear= Safe
Reinforcement at Top (z-direction) Max BM(T-m)=
15.95 t-m
%pt(as per IS:456-2000) =
0.228
Ast use bar dia (mm) = Area Spacing of reinforcement required(mm)= Provide reinforcement=
1184.17 mm2 16 mm 2.01 sq.cm 169.79 mm 160 mm
PROJECT:
DESIGN OF COMBINE FOOTING
TITLE :
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
Y16-160c/c
Provide reinforcement= Steel provided
Distribution steel
[ Min.
0.06
use bar dia (mm) = Area Spacing of reinforcement required(mm)= Provide reinforcement= Provide reinforcement= Area of steel provided=Ast= %pt(provided)=
%]
360 mm2 12 mm 1.13 sq.cm 314.16 mm 200 mm Y12-200c/c 565.49 mm2 0.333 %
PROJECT:
DESIGN OF COMBINE FOOTING
TITLE :
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
Summary
1
Y12-200c/c
Y16-160c/c
600
Y12-170c/c
1 SECTION IN Z-Z DIRECTION(THROUGH PIERS)
Y12-200c/c Y20-200c/c
600
2
2 3 Y12-100c/c
Y12-200c/c
3
SECTION-1-1 Y12-200c/c
Y20-200c/c
SECTION 2-2 :REINFORCEMENT AT TOP
Y16-160c/c
PROJECT: TITLE :
DESIGN OF COMBINE FOOTING
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
Y12-200c/c
4.00m
2.80m
Y12-100c/c
Y12-170c/c
SECTION 3-3 REINFORCEMENT AT BOTTOM 600
Footing thickness,D,(mm)=
check for punching shear
85.5 t
Critical vertical load for punching Punching shear-length
2.400 m
Punching shear-width
1.500 m 154.08 t
Upward force=
9.6 m2
Area for punching shear
68.58 t
Punching shear force Punching shear stress
0.14 N/mm2
Allowable shear stress
0.80 N/mm2
Permissible shear stress as per 456-2000 Where
Ks
=
c
=
ks xc
(0.5+bc) but no greater than 1, bc being the ratio of short side to long side of column
c
=
0.7
Ks
=
1
PROJECT:
DESIGN OF COMBINE FOOTING
TITLE :
c
=
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
0.25 x Sqrt(fck) (for limit state design)
=
1.25
N/mm
2
ks xc c v
<
=
1 x 1.25
=
1.25
N/mm2
c
SAFE Check for uplift:
0.000 t
Max.upward force= Downward force
17.125 t
weight of foundation
37.375 t
Dead load of structure=
54.500
Net force=
safe Check for Overturning (a) Check for overturning in x-x direction:
2.959 t-m
Disturbing moment=Mz=
77.4625 t-m
Stabilizing Moment=Mz'
26.18
Factor of safety= (b) Check for overturning in z-z direction
safe
Disturbing moment=Mx=
62.5260 t-m
Stabilizing Moment=Mx'=
72.86 t-m 1.17
Factor of safety=
safe
PROJECT: TITLE :
DESIGN OF COMBINE FOOTING
DOCUMENT NO.
DATE
DESIGNED CHECKED
PAGE
Check for sliding: Vertical load
93.50 t
Reaction from structure Self weight of foundation=
