Study on damage evolution characteristics of the deep roadway surrounding rock with fault based on microseismic monitoring and fractal theory

Based on the investigation of the Lannigou gold deposit in southwest Guizhou, numerical simulations were conducted to analyze damage progression in the hazardous section of the roadway, focusing on crack distribution and the evolution of fractal dimensions in the surrounding rock. The simulation results were subsequently validated using microseismic characteristics. The findings show that the box dimension value of surrounding rock fractures increased prior to failure, indicating that the extent of rock damage can be quantitatively assessed through the fractal dimensions of fracture distribution. Near the fault, the rock mass damage degree reached 8 % at the point of failure, while surrounding rocks with more favorable lithology exhibited damage degrees exceeding 11 %. Additionally, the microseismic event energy index dropped sharply, whereas the cumulative apparent volume increased gradually before severe roadway damage occurred. Thus, fractal dimensions combined with numerical simulation results can be used to evaluate the rock mass, and microseismic monitoring can help identify critical periods of roadway instability to support safe production.