Elastic Modulus and Strength of Rock-Like Material with Locked-In Stress

Locked-in stress is a special stress objectively existing in the rock which has an important influence on the mechanical properties. However, there were few studies on the locked-in stress in rocks. The locked-in stress was simplified into spherical inclusions of stress. Based on the Eshelby inclusion theory, the influence equation of the locked-in stress on the elastic modulus of the rock is derived. Through experiment, the expression of elastic modulus of rock-like material with locked-in stress based on M-T method is determined. Based on Mohr-Coulomb criterion and effective stress principle, the equations for the influence of locked-in stress on strength of rock-like material under uniaxial and conventional triaxial conditions were deduced. Through experimental verification, an empirical formula for the strength of rock-like material containing locked-in stress is obtained. This article provided a method for further studying of the locked-in stress in rock-like material and has certain reference value.