Safe Bearing Capacity of Soil

 Safe Bearing Capacity of Soil

 The capacity of the soil to allow the loads coming from the foundation is called the bearing capacity of the soil.

It is essential to know the bearing capacity of the soil before designing the foundation. Different field tests can determine it. However, standard safe bearing capacity values are available for different soil types, and these values can be assumed where test data is limited or speedy construction is required.

S.No	Type of Soil	Safe Bearing Capacity ( kN/m2)
	Cohesive Soils
1.	Soft shale, hard or stiff clay in a deep bed, dry state	440
2.	Medium clay readily indented with a thumbnail	245
3.	Moist clay and Sand clay mixture, which can be indented by thumb pressure	150
4.	Black cotton soil/expansive clay ( 50% saturated) in the dry state	130 to 160
5.	Soft clay indented with moderate thumb pressure	100
6.	Very soft clay which can be penetrated with the thump up to few centimeters	50
	Cohesionless Soil
7.	Compact gravel/sand and gravel mixture with good resistance against penetration of tools	440
8.	Compact and dry coarse sand	440
9.	Compact and dry medium sand	245
10.	Loose gravel or sandy gravel mixture, dry state	245
11.	Fine sand and silt ( consists of dry lumps)	150
12.	Loose and dry fine sand	100
	Rocks
13.	Hard rocks such as granite trap, diorite, etc.	3240
14.	Laminated rocks such as sandstone, limestone, etc.	1620
15.	Residual deposits of shattered and broken bedrock and hard shale cemented material	880
16.	Soft rocks	440

The Ultimate Bearing Capacity: The gross pressure intensity at the base of the foundation which would cause shear failure of the soil.