STUDY ADVANCE ON BASIC CHARACTERISTICS AND FORMATION CAUSES OF ROCK INNER STRESS

The history and current research status of the internal stress in the residual stress of rock are reviewed and important meanings of research on the internal stress are pointed out in this paper. The basic characteristics of internal stress in rock are analyzed and the formation cause and mechanism are concluded and discussed. Based on analysis, we conclude that the elastic and plastic characteristics and inhomogeneous plastic deformation are necessary condition for locking internal stress of rock, and external loads. Physical and chemical effects and thermodynamic functions are the direct power to store internal stresses. Determining principle and measurement techniques of internal stress in rock are analyzed and summarized respectively. We believe that the plastic deformation is the fundamental cause for releasing of internal stress. Besides, internal stress in rock may affect mechanical behavior, to which attention should be pay.