Multi-scale effect of acoustic emission characteristics of 3D rock damage

Scale effect and acoustic emission characteristics of rock damage are two important topics in rock engineering research. In this paper, considering different rock scales and establishing the 3D numerical rock models by means of PFC software platform firstly, the mechanical properties and acoustic emission characteristics were studied. Finally, based on the acoustic emission, characteristic discussed the damage evolution law of the rock models. The research result shows that the multi-scale mainly affects the peak strength, peak strain, and elastic modulus of the mechanic properties, affects the maximum acoustic emission event number, strain range of serious acoustic emission events of the acoustic emission characteristics, affects the damage rapid increase and damage failure stages of the damage evolution process. The stress-strain curves, acoustic emission events curves, and damage variable curves can be divided into three stages and different scales have different effect on these stages.