If a soil undergoes a change in shape and volume by application of external loads over it, but recovers its shape and volume immediately after removal of the load, the property of the soil is said to be

Soil mechanics is the theory of mechanical properties of soils. Foundation engineering - the theory of stability of foundations and construction methods used for their production. This also includes predicting the deformation of the substrate.

The objectives of soil mechanics are (1) to study the physical and mechanical properties of soil, (2) to apply this knowledge for the solution of practical engineering problems, and (3) to replace by scientific methods the empirical ones of design used in foundation and soil engineering in the past.