Abstract: In order to study the relationship between acoustic emission characteristic parameters and strain, stress and damage variable of rock under different failure models, the tests have been made to obtain the characteristics of acoustic emission of sandstone, leptynite, granite and limestone using hydraulic-pressure servo testing system RMT-150C and acoustic emission instrument SAEU2S under the uniaxial compression. Results have shown that the cumulative acoustic emission ring-down count of rocks with brittle or brittle-ductile failure model increases sharply before the peak stress, while accumulative ring-down count of rock with ductile failure model surges before a quiet period, which can be considered as a precursor for entering failure phase. With time being intermediate variable, the relational model between cumulative acoustic emission and strain generated from rock with brittle, brittle-ductile and ductile failure has been set up, and the coupled relation among cumulative acoustic emission, damage variable and stress has been deduced based on the Weibull distribution constitutive model. Proved by the test data, the precision of constitutive model with brittle, ductile failure is higher, which can provide accurately the basis for rock damage assessment.

Key words: stress, strain, failure model, accumulative ring-down count, damage variable, constitutive model