Research on the mining pressure law of gob-side roadway under the influence of fault tectonic zones and hard roofs

To investigate the mining pressure behavior of gob-side roadways influenced by fault tectonic zones, the Xinjulong Coal Mine is taken as the engineering background. The initial stress distribution and the effects of fault parameters on stress evolution were analyzed through theoretical analysis. Numerical simulation and three-dimensional model tests were then conducted to examine the stress and displacement evolution of the gob-side roadway and overlying strata. The results show an asymmetric stress distribution near the fault, with the hanging wall bearing higher stress than the footwall. The gob-side roadway is simultaneously affected by the abutment pressure of the adjacent gob and the fault-induced tectonic stress. During roadway excavation and working face mining, the maximum stress in the coal pillar of the gob-side roadway is 1.8 times that in the non-gob-side roadway. The height of the collapsed arch is approximately 36 m, with a collapse step distance of 40 m. Under the combined influence of the adjacent gob, fault tectonic, and mining-induced abutment pressure, the stress concentration is significant. The hanging wall of the fault and the coal pillar together constitute a high static stress zone, where substantial elastic strain energy is accumulated. Meanwhile, the abrupt collapse of a hard roof exerts intense dynamic disturbances on the gob-side roadway already subjected to high stress, thereby creating the inducing condition for rockburst under the coupled effect of high static and strong dynamic loads.