1.1 Eccecntric Footing.xlsx

	B	C	D	E	F	G	H	I	J	K	M
1
2		DESIGN OF RCC ECCENTRIC FOOTING
3	Material Data
4	fy =	415	N/mm2
5	fck =	20	N/mm2
6	Unit weight of soil =		16	kN/mm2
7	Depth of foundatioon		=	2
8	Bearing capacity of the soil			sbc =	80	KN/m2	at	1.5 m	below NGL
9
10	Size of column			0.23	m x	0.3	m
11				230	mm x	300	mm
12	Area of column		=	0.069	m2
13
14	Provide footing of size		L =	2.13	m (OR)	2130	MM
15			B =	2.13	m (OR)	2130	MM
16	Area of footing provided =			4.54	m2
17
18
19	Support reaction		=	120
20	Soil load
21	(4.54 - 0.069 ) x 2 x 16		=	143
22		Total	=	263	KN
23
24	Assume 1 m wide footing
25		1 PX	x 1 =	263
26		2
27		1 x 80 x X	=	263
28		2
29		X	=	263
30				40
31	Area of footing		=	6.6	m2
32	Size of footing		=	2.57	m
33
34	Eccentricity		=	1 x 2.13	-	0.23
35				3		2
36			=	0.71	-	0.12
37			=	0.59	m
38	Moment due to eccentricity
39			=	120 x 0.59
40			=	70.8	KnM
41	Additional moment		=	22.5	KnM
42		Total	=	70.8 + 22.5
43			=	93	KnM
44
45	CHECK FOR BASE PRESSURE
46
47			=	P	+	M
48				A		Z
49			=	263	+	93 x 6
50				2.13 x 2.13		2.13 x 4.5369
51			=	57.96909784	+	57.74
52	Max. Pressure		=	115.71	KN/m2
53	Min. Pressure		=	0	KN/m2
54
55
56
57
58
59								XX- AXIS
60
61							2.13	M
62
63	PRESSURE ABOUT XX - AXIS						L
64	P=	120	KN/m2
65	P =	143	KN/m2								TABLE 2 OF
66	Pmax =	115.71	KN/m2						0.95		SP 16
67	Pmin =	0	KN/m2
68				ZZ -AXIS
69	PRESSURE ABOUT ZZ - AXIS				B				0.23
70				2.13	M					0.472
71	P =	120	KN/m2
72	Pmax =	72.34	KN/m2
73	Pmin =	57.63	KN/m2						0.95
74
75
76
77			B			1.83		0.3
78
79			2.13	M		1.71		0.42
80						1.588
81			65.78	67		86.27		99.41
82					0
83
84							92.89
85	57.63	KN							115.71	KN
86				67	72.34
87			ABOUT ZZ- AXIS		KN		ABOUT XX- AXIS
88
89
90	BENDING MOMENTS AT FACE OF COLUMN										TABLE 2 OF
91											SP 16
92	MAX. B.M AT FACE OF COLUMN ABOUT XX AXIS
93
94	Cantilever projection along longer face				=	(2.13 - 0.3)
95
96					=	1.83	m or	1830	mm
97
98	Pressure at face of pedestal				=		115.71 x 1.83
99							2.13
100					=	99.41	KN/m2