Bearing Capacity Of Soil

Bearing capacity is the ability of the sub-soil to support the loads(dead loads and live loads etc) of the structure coming over it without any yielding. It depends upon the characteristics of the soil particles. Lesser the voids in the sub-soil, greater is its strength to carry loads. The minimum load which may cause the failure of the foundation is called ultimate bearing power of the soil.


The ultimate bearing capacity of the soil is given by

   =  W/area of the plate(where W is total load and at the base plate used for the test is 30cm x 30cm area)

and safe bearing of soil = Ultimate bearing capacity/factor of safety.

Safe bearing capacities of different soils are given below : 

S.No	Type of Soil	Safe Bearing Capacity in tonnes/m2
1	Soft clay, marshy clay, etc.	2 to 3.75
2	Black cotton soil	5 to 5.75
3	Made up ground	5
4	Alluvial soil	7.5 to 16
5	Moist clay	10 to 18
6	Ordinary clay	22
7	Sand mixed clay	22
8	Compact sand	44
9	Compact gravel	43 to 55
10	Moorum	65
11	Soft Rock, Ordinary Rock	110
12	Hard Rock	Above 200