Research on Damage and Acoustic Emission Properties of Rock Under Uniaxial Compression

Abstract

In this paper, the YSSZ-500A rock biaxial rheological tester was used to investigate the acoustic emission characteristics of coal seam roof rock under uniaxial compression, and analyzed the acoustic emission characteristics, fracture mode and energy damage mechanism in the progressive failure process, and study the damage characteristics of rock samples from the perspective of damage mechanics. The results are as follows: (1) The whole stress–strain process of uniaxial compression can be divided into three stages: compaction stage, linear elastic stage, yield stage and failure stage. (2) In the middle of the period, the AE of the sample increases slowly and rapidly in the process of compression. For AE, the logarithm of the corresponding AE cumulative ring count can be divided into rapid increase period, slow increase period and sharp increase period. (3) The damage constitutive model of specimen during uniaxial compression is established, and the relationship between damage variable and axial strain is analyzed. (4) The energy absorbed by the specimen before the peak is mainly in the form of releasable elastic strain energy, and part of the energy is dissipated by the specimen damage propagation, and the energy dissipation is mainly concentrated in the yield section. A large amount of elastic strain energy is released after the peak, and most of the released energy is transformed into the energy dissipated by the propagation of fracture surface through the surface, which leads to the instability of rock samples.