Geotechnical engineering is an important field of engineering that is concerned with the behavior of earth materials.

 

Geotechnical engineering is the discipline within civil engineering related to the performance of soil mechanics, including their subsurface conditions, determination of the physical, mechanical, and chemical properties that will influence the project under consideration.

Bearing capacity of soil:
Bearing capacity is the power of foundation soil to hold the forces from the superstructure without undergoing shear failure or excessive settlement. Foundation soil is that portion of ground which is subjected to additional stresses when foundation and superstructure are constructed on the ground.

 

Selection of foundation based on different types of soil:
Foundations are recommended based on the different soil types which are provided below:

1.Rocks: This category involves rocks, hard sound chalk, sand and gravel, sand and gravel with little clay content, and dense silty sand. Recommended foundation types

• Strip foundation

• Pad foundation

• Raft foundation.
   

2.Uniform firm and stiff clay: Recommended foundations:

• Strip foundation

• Pad foundation

• Raft foundation.

3.Soft clay: This category includes soft clay, soft silty clay, soft sandy clay, and soft silty sand.. Recommended foundations:

• Wide strip footing

• Raft foundation

• The pile to firmer strata below

For smaller projects use pier and beam foundation to firm strata

4.Peat: Concrete piles extended to the firm soil layer below

For small projects, pad and beam foundation taken to firm strata blow.

 

Raft foundation for the case where firm strata are not available at reasonable depth but there is a hard surface crust with the 3-4m thick of suitable bearing capacity.