ABSTRACT
The study of soil mechanics is to predict the stresses and strains imposed at a given point in a soil mass due to certain loading conditions. This chapter presents the theories of stresses and strains are for the elastic range only. In determining stress and strain in a soil medium, one generally resorts to the principles of the theory of elasticity, although soil in nature is not fully homogeneous, elastic, or isotropic. The normal stresses are considered positive when they are directed onto the surface. In soil mechanics, a number of problems can be solved by two–dimensional stress analysis. Generally, in soil mechanics, the compressive normal strains are considered positive. The axial strains for an ideal, elastic, isotropic material in terms of the stress components are given by Hooke's law. A plane is defined as a principal plane if the shear stress acting on it is zero.
