1.2 Isolated Footing.xls

	A	B	C	D	E	F	G	H	I	J	K
1	Project		XXX				Design of Isolated footing
2			XXX				Designed by		Date		Page
3	Client		XXX				XXX
4			XXX				Checked		Revision		Job No
5	Strl. Consultant		XXX				XXX		-		XXX
6	Ref.	Calculations
7		Footing	F1							INVALID DESIGN
8		P =	967	kN	fck =	20	N/mm2
9		Mx =	0	kN-m	fy =	415	N/mm2	Density of concrete		25	kN/m3
10		My =	0	kN-m	cover =	50	mm	Density of Earth		18	kN/m3
11		SBC =	150	kN/m2	Dia. of bar	along L	10
12						along B	10
13
14		Depth of excavation (from finished flr.Lvl.) =					1.50	m
15
16		Column/Pedestal Details
17				b =	400	mm
18				h =	400	mm
19
20		Area required =			7.74	m2
21
22		Provide
23				L =	2000	mm
24				B =	3450	mm
25				D =	600	mm
26		Area provided =			6.9	m2
27
28		Weight of backfill =			111.78	kN
29
30		Self weight of footing =			103.50	kN
31
32		Final area of footing reqd.=			7.88	m2
33
34		Bearing pressure at four corners							Bearing pressure =
35			Corner 1	=	140.14	kN/m2	OK		P/A ± Mx/Zy ± My/Zx
36			Corner 2	=	140.14	kN/m2	OK
37			Corner 3	=	140.14	kN/m2	OK		where Zx =BL2/6
38			Corner 4	=	140.14	kN/m2	OK		and Zy =LB2/6
39
40		To find Design Moments
41		x - direction
42			Mx	=	325.92	kN-m
43
44		y - direction
45			My	=	154.72	kN-m
46
47		Check for thickness of footing
48
49			Mu,lim	=	0.138	fckbd2
50
51		For, Mx =	325.92	kN-m
52			d	=	297.6011643	mm	OK
53
54		for, My =	154.72	kN-m
55			d	=	156.12	mm	OK
56
57		Reinforcement
58
59		Axis	M	Mu/bd2	pt(req)	Ast	Dia	Reqd. Spacing	Spacing provided	Ast(prov)	pt(prov)
60		Axis	M	Mu/bd2	pt(req)	Ast	Dia	Reqd. Spacing	Spacing provided	Ast(prov)	pt(prov)
61		Along L	325.92	0.48	0.14	2557.98	Y10@	100 c/c	175 c/c	1548.36	0.08
62		Along B	154.72	0.41	0.12	1284.00	Y10@	100 c/c	175 c/c	897.60	0.08
63
64		Check for punching shear(Two way shear)
65		The section for punching shear is taken at a distance of d/2 from the face of column/pedestal
66
67		Perimeter		=	3780.00	mm
68		Shear force		=	841.85	kN
69		Shear stress		=	0.62	N/mm2	OK		945	945
70
71		Permissible stress		=	1.118033989	N/mm2
72
73										945
74		Check for One way shear
75		The section for punching shear is taken at a distance of d from the face of column/pedestal
76		Along L
77		Shear force		=	123.29	kN
78		Shear Stress		=	0.10	N/mm2	OK
80		Permissible stress		=	0.23	N/mm2
81
82		Along B		=
83		Shear force		=	274.68	kN
84		Shear Stress		=	0.38	N/mm2	Fails
86		Permissible stress		=	0.24	N/mm2
87
88
89					2000
90
91										CHECKS
92						D = 600				Bearing	OK
93										pressure
94									One way shear		Not OK
95
96								3450		Punching Shear	OK
97		Y10@	175 c/c
98
99
100
101
102						Y10@	175 c/c