Study on the Energy Evolution and Stability of Roadway Surrounding Rock Under the “Simultaneous Mining–Driving” Condition

ABSTRACT This study elaborates on the concepts of total elastic energy, elastic volumetric energy, elastic deviatoric energy, total plastic energy, plastic volumetric energy, and plastic deviatoric energy involved in the deformation and failure of rock masses. A plastic energy increment formulation is further derived. Based on in‐situ measurements of the maximum, intermediate, and minimum principal stresses in the Xiaojiawa Coal Mine, representative stress values are substituted into the theoretical model, enabling an accurate characterization of the energy evolution of the roadway surrounding rock under the influence of mining‐induced approaching excavation. Numerical simulations are subsequently conducted to analyze the energy evolution and deterioration behavior of the surrounding rock during the approaching process, and the results agree well with the theoretical predictions. During the advance of the 120803 longwall panel toward the 221303 belt roadway, the surrounding rock at 2.5 m into the solid‐coal rib remains in a persistent plastic state, indicating pronounced degradation. When the distance between the 221303 material roadway and the 120803 working face reduces to approximately 100 m, the plastic zone initiates and extends from the solid‐coal side at a depth of ~2.5 m toward greater depths, accompanied by a progressive deepening of the surrounding‐rock deterioration zone. Concurrently, the elastic strain energy around the roadway gradually decreases, whereas the plastic dissipation energy continues to increase. When the belt roadway is 100 m ahead of the longwall face, the surrounding rock at 6.5 m into the solid‐coal rib begins to undergo a transition from elastic energy accumulation to plastic energy dissipation, signifying severe and irreversible deterioration. The plastic zone has extended approximately 6.5 m into the solid coal side. In contrast, the rock mass at 10.5 m remains elastic. When the roadway and longwall face become aligned, elastic energy begins to accumulate at 10.5 m, and the deterioration zone expands correspondingly.