Case Study: Bearing Capacity

Case Study: Bearing Capacity

Bearing capacity is the maximum stress that the loads could be applied to the soil. Bearing capacity is an important factor when determining the size of the columns of a structure. Without bearing capacity, the structure would have failed or sunk into the soil.

Bearing capacity can be tested through the following procedures for a rough calculation:

• Dig out a hole that is the same depth as the depth of the structure.
• Pick out a known mass and dimension of an object (a solid ball or a cube is suggested).
• Drop the ball or the cube from a known height into a hole.
• Calculate the average depth of impression (d) from the hole.

After this quick test, the resistance of soil can be calculated using the equation:

R = (w x h)/d

R is the ultimate resistance of soil, w is the weight (kg) of the object that is being dropped, h is the known height (cm) that the object is being dropped from, and d is the average depth of impression (cm) that the object has made on the surface of the hole.

After figuring out R, a safe bearing capacity can be calculated by the following equation:

Bearing Capacity (kg/cm²) = R/(A x F.O.S)

R is the resistance of soil that can be found using the equation above. A is the cross sectional area of the object that is being dropped (solid ball or cube). F.O.S is the factor of safety which can range from 2 to 3 depending on the structure and the site.

Link: http://civilblog.org/2015/02/23/how-to-calculate-safe-bearing-capacity-of-soil-on-site/