CRITERIA FOR STRENGTH AND STRUCTURAL FAILURE OF ROCKS BASED ON ENERGY DISSIPATION AND ENERGY RELEASE PRINCIPLES

The intrinsic relations between energy dissipation,energy release,and strength and abrupt structural failure of rocks during failure process are discussed.It is emphasized that the failure of rock is a process in which energy dissipation and energy release occur simultaneously.The energy,part of work done by external forces,dissipates to produce damage and irreversible deformation inside rock and makes the material deteriorate and its strength drop down eventually.The strain energy released in rock volume plays the pivotal role of abrupt structural failure of rock.The concepts of energy dissipation,energy release,strength loss and abrupt structural failure of rock are defined.On the basis of these concepts,the criteria for strength and abrupt structural failure of rock are proposed.The critical stresses at the time of abrupt structural failure of rock under various stress states can be determined by these principles.The energy criteria have been applied to analyzing the failure condition of surrounding rock masses of a circular tunnel in practice.