Question
Terry Collins
Sustainability consultant
Asked a question 2 years ago

# What are Bearing Capacity Values of Different Types of Soil?

What are the bearing capacity values of different types of soils such as clay, sand, gravel, rocks etc.?

### Where am I?

Following table shows maximum bearing capacity values of different types of soils:

Bearing capacity of soil is the maximum load per unit area. This is the ultimate bearing capacity of soil shown in table. Dividing the ultimate soil bearing capacity by a safety factor we get the maximum safe bearing capacity of soil for design of foundations.

Review the Calvin first column, it's wrong, the correct value must be: the tabla value divided by 10000

1 kg = 10 N, so, 1000 N = 100 kg = 1 kN. So, value of column 2 is divided by 100 to obtain value in kN/m2.

Flenn Hale
Construction Manager

Dear Calvin, thankyou for this informative.

I have an additional query. How does one deduce the soil type (among the above mentioned types) by visual inspection or simple field tests ?

Seth Morgan
Construction Superintendent
Can I get step by step on how to find out SBC if cohesion=0.36 kg/cm²,angle of internal friction=13,Field dry density=1.603,fmc=12%.
Theodore Ray
Planning and development surveyor
correct
Manuel Mason
Of course these are indicative values â€‹â€‹and do not substitute for soil testing by a specialized laboratory.
Is it always correct to utilize smaller value of SBC even though the kind of material is loose of soft clay and yet within this value the structure is still safe and sound. Regards and thanks. Juliet magtalas
Raul Jimenez
Senior Project Manager
Different soil SBC are as follow Bedrock is 574kpa Gravel is 250kpa Sedimentry Rock is 190kpa Sand gravel is 140kpa Sand,silt sand, clayey sand is 95kpa Clay, sandy clay, silty clay is 70kpa In actual site, we conduct several test to find out SBC.

The bearing capacity values for different types of soil are- Clay : 100 KN/sq.m sand : 400 KN/sq.m Gravel : 300 KN/sq.m Rocks : 3240 KN/sq.m

Construction Assistant

For the different values of bearing capacity factor under the application of general shear failure, values are shown in the above table. Where Nc, Nq and Ny are the factors of Terzaghi's bearing capacity.

Jerry Henry
Architectural technician

Follwoing are the values of safe bearing capacity as per IS:1904–1978 –

Rocks -

a) hard sound rock - 330 t/m2 or 3240 KN/m2

b) leminated rock - 165 t/m2 or 1620 KN/m2

c) residual deposit of shattered and broken rocks- 90 t/m2 or 880 KN/m2

d) soft rock - 45 t/m2 or 440 KN/m2

Non Cohesive Soil (sand & gravel ) -

a) compact gravel, sand and gravel - 45 t/m2 or 440 KN/m2

b) compact and dry coarse sand - 45 t/m2 or 440 KN/m2

c) compact and dry medium sand - 25 t/m2 or 245 KN/m2

d) find sand - 15 t/m2 or 150 KN/m2

e) loose gavel or sand - 25 t/m2 or 245 KN/m2

f) loose and dry fine sand - 10 t/m2 or 100 KN/m2

Cohesive soil -

a) hard or stiff clay, soft shale - 45 t/m2 or 440 KN/m2

b) medium clay - 25 t/m2 or 245 KN/m2

c) moist clay and sand clay mixture - 15 t/m2 or 150 KN/m2

d) soft clay - 10 t/m2 or 100 KN/m2

e) very soft clay - 5 t/m2 or 50 KN/m2

f) black cotton soil , peat - by soil investigation

This is bit difficult to state like this. Generally, in fields, we deal with layered soil systems where in you need to work out settlement of each layer and then compare the same to allowable settlement of the subject structure. The allowable settlement for each structure in different and hence the criterion changes all the time.

More than shear criteria, the settlement criteria generally governs the safe bearing capacity of a soil. So, it is difficult to standardize the bearing capacity values in case of soils. May be, in the case of rock, you can standardize the values as the rock does not settle more than 3-4 mm.