MECHANICAL PROPERTIES AND STATISTICAL DAMAGE MODEL FOR WHOLE DEFORMATION PROCESS OF ANCHORED LAYERED LIMESTONE UNDER UNIAXIAL COMPRESSION TEST

In order to study the mechanical characteristics of the anchored layered limestone under different anchored angles, WAW-3000 kN servo universal hydraulic testing machine and the PCI-2 AE system were used to study uniaxial compression and the AE characteristics of the anchored layered limestone specimens with different anchored angles. Based on the experiments, the mechanical parameters of anchored layered limestone specimens such as elastic modulus, Poisson's ratio, peak strength, and their variation with rock bolt angle were obtained, and the variation laws of acoustic emission characteristics were also analyzed. The results show that the mechanical parameters of anchored layered limestone exhibit obvious anisotropic characteristics and their variation laws of acoustic emission energy are related to different deformation stages. Furthermore, the relationship between the void and skeleton deformation of anchored limestone is comprehensively analyzed, and the deformation analysis method for the whole process and elastic damage evolution model of anchored limestone considering the compaction effect are established based on the variation laws of acoustic emission characteristics. Comparing with the results of the mechanical model and the test curves, they fit well, which reveal the nonlinear deformation in the void compacting stage at the beginning of loading and the cumulative damage failure in the middle and later stages of the anchored limestone can be well reflected by this model.