Investigations on the Law of AE Energy Accumulation and Damage Evolution of the Coal and Rock

Abstract

Rocks and other rocklike solid materials have inherent defects in its interior. The defects of rock will be evolved under the outside loading. The evolution process and extent of defects can be depicted by the damage variable. But which physical or geometrical parameter or parameters can be used to define the damage, there has no consistent conclusion in home and aboard. Moreover, limited by the method of experimental measure, it is difficult to obtain the parameters to describe the damage variable directly. In order to obtained the evolution law of the interior defects in the solid material, the non-conduct geophysical prospecting measure as AE (Acoustic Emission) will be the leading measure to prospect the interior defects and it’s evolution under outside loading. In the present paper, the AE method was used to obtained the AE parameters during the uniaxial compression process of coal and rock. Thus wise, uniaxial compression and AE tests on coal and mudstone were conducted, and the curves among the AE energy accumulation, stress and strain were obtained after analyzing the results of tests data. Based on the principle of damage mechanics and thermodynamics, the damage evolution of coal and rock was deduced through analyzing the experimental results, the curves of damage and AE accumulation were obtained also. By analyzing and fitting the curves of damage and AE energy accumulation, the relation between the AE energy accumulation and stress-strain was obtained and verified through the experimental data.