Rock Damage Evolution Of The Theoretical And Experimental Studies Of The Model And The Damage Threshold

Rock damage mechanics is a new offset of rock mechanics developed in 1980's, it researches the failure process and rules cause by the development of small crackles and cavities. On account of the complexity character of rock mechanics, there is no accepted or applied rock damage evolve model and failure criterion, so it is important to build these evolve model or failure criterion. The paper try to make research in this aspect.The paper studies the following aspects: 1. the paper will use renormalization group technique to research critical damage in the moment the rock wrecked. The result indicate the critical damage in the isotropy material is smaller than general opinion and the critical damage is about 11 % ,the result also indicate its validity compare with the result of red-sandstone mechanical test. 2. the paper discuss the problem of rock isotropy damage and build a damage model which is applicable to softrock, this model consider there is made by small crackles and cavities before the rock is loaded, so it is indispensable to calculate the negative damage factor when damage model is built.3. the paper discuss two-scalar rock damage model. Generally it use elastic modulus and shear modulus to describe two-scalar model, but it is discommodious in rock damage mechanics, so the paper use elastic modulus and poisson ratio to describe two-scalar rock damage model.