The study of mining-induced behaviors of faults and strata in underground coalmines is significant to know the mechanism and prediction of some accidents (i.e., water inrush, gas flowing and outburst). Equivalent materials are applied herein in an underground project to simulate a progressive mining operation with a normal fault occurrence. The failure–movement evolution of the overlying strata and the stress–displacement evolution of the fault are studied through a physical simulation test. The formation of a mining-induced fracture and the mechanism of accidents caused by the mining-induced fracture are analyzed. The results show that the footwall strata underwent a more notable movement compared to the hanging wall strata. Hence, the mining-induced fracture height of the footwall is higher than that of the hanging wall. The effect of the fault can be observed on the mining-induced fracture evolution of the footwall, hanging wall, and fault plane. The developed patterns of the fracture channel successively present an evolution in the shape of a “saddle”, a “trapezium”, and an “M”. The causes of accidents induced by the mining fracture are also discussed.
Micro-mechanical behaviors of rock masses with structure planes can provide information regarding precursory characteristics of macro-fracture of strata and rock bursts. Hence, numerical simulation with uniaxial compression test is conducted using Realistic Failure Process Analysis (RFPA). Then, mechanical properties and progressive failure processes for rock masses with different dip angle structure planes are studied, and the macroscopic fractures, mechanical responses, and acoustic emission (AE) responses of rock masses are analyzed. Moreover, the strength weakening and interface slipping effects with different dip angle structure planes are revealed. The results show that rocks with different dip angle structure planes show significant strength and interface slipping effects. A small dip angle structure plane has little influence on the rock strength and interface slipping, which mainly manifests as failure in rock interiors. For medium dip angle structure plane, the rock strength decreases obviously, and interface slipping is notable along the structure plane. The effects caused by the weak plane are more prominent with rising dip angles. Compared to rocks with small dip angle structure planes, those with medium dip angle structure planes are more easily broken. However, the total energy released and total AE counts are smaller, indicating less serious bursting liability from rock failure.