Research Progress of Effective Stress and Effective Stress Equation

In 1920’s and 1930’s, Terzaghi presented the concepts of effective stress and the effective stress equation based on tests and engineering experience, which were concluded into the principle of effective stress by Jennings in 1961: firstly, effective stress equals total stress minus pore water pressure; secondly, the effective stress controls the strength and deformation of a soil. The principle of effective stress is considered the keystone of soil mechanics.