DAMAGE MECHANICAL CHARACTERISTICS OF ROCK UNDER FREEZE-THAW AND LOAD COUPLING

The paper derives the damage evolution equation in terms of freeze-thaw cycle and strain for the freeze-thaw and loaded rock based on micro mechanical mechanism and using the methods of macro phenomenological damage mechanics and non-equilibrium statistics. The real damage propagation constitutive relation of the freeze-thaw and loaded rock is established by using the generalized theory of strain equality. And the evolutionary route of micro-structural damage and materials mechanical properties for the rock are discussed. It is shown that the damage of freeze-thaw rock is mainly caused by fatigue. The dual effect of the freeze-thaw and the load on the rock damage presents obvious nonlinear property, and the coupling effect weakens the whole damage. Moreover, the influence of freeze-thaw cycle and strain on the damage propagation is determined by the lithology and the initial damage state of the rock..