Study on the Influence of Initial Disturbance Values on Coal Rock Bodies Fracture Damage Under Different Soft Rock Ratios

This study conducted low-frequency disturbance loading experiments on soft rock–coal combinations with different coal–rock ratios under different initial disturbance values to research the mechanical properties and fracture modes of the combinations. Research results are shown as follows: (1) As the initial disturbance value increases, the bearing capacity of combinations with varying proportions of rock also increases. (2) The acoustic emission b value of combinations exhibits significant fluctuations during both the disturbance and the pre-destruction phase, showing an opposite trend to the sudden increase and decrease in stress. And the absolute energy gradually decreases as the initial disturbance value increases during destruction. (3) The acoustic emission RA-AF results indicate that as the initial disturbance value increases, the proportion of tensile cracks in the specimen also increases. (4) The realistic failure process analysis (RFPA) numerical simulation combined with actual failure jointly demonstrates the failure and fracture behavior of the combinations.