Geotechnical engineering is a branch of civil engineering which deals with the study of soil, its properties and its behaviour starting from its origin to various engineering applications. Geotechnical engineering is one of the youngest disciplines of civil engineering which is also known as soil engineering. Soil Engineering is currently used to cover a much wider scope, implying that it is a practical science rather than a purely fundamental or mathematical one.

Geotechnical engineering is further divided into two categories. The two categories are

1. Soil Mechanics: “Soil mechanics is the application of laws of mechanics and hydraulics to engineering problems dealing with sediments and other unconsolidated accumulations of solid particles produced by the mechanical and chemical disintegration of rocks regardless of whether or not they contain an admixture of organic constituent”.
   The above definition of soil mechanics was given by Dr.Terzaghi (1948).

2. Foundation Engineering: “Foundation engineering is a branch of civil engineering which is associated with the design, construction, maintenance and renovation of footings, foundation walls, pile foundations, caissons and all other structural members which form the foundations of buildings and other engineering structures”.
   The above definition of foundation engineering was given by Taylor (1948).

3. Rock Mechanics: Rock mechanics is a theoretical and applied science of the mechanical behaviour of rock and rock masses; It is that branch of mechanics concerned with the response of rock and rock masses to the force of fields of their physical environment.