ABSTRACT
The concept of effective stress was proposed by K. Terzaghi in 1923. He pointed out that the effective stress is equal to the total stress minus the pore water pressure, and the effective stress determines the deformation and strength of a soil. Terzaghi’s effective stress principle had been stated by J.E.B. Jennings in the form of two propositions: (i) Changes in volume and shearing strength of a soil are due exclusively to changes in effective stress. (ii) The effective stress in a soil is defined as the excess of the total applied stress over the pore pressure. The consolidation theory, the strength and deformation theory in addition to stress-strain relationship based on the principle for saturated soils were proved to be applicable in practice. The effective stress principle has been recognized to be the foundation of modern soil mechanics and the effective stress is one of the most important concepts in soil mechanics.
