To understand and master the evolving patterns of mining-induced stress is a key issue to control and utilize the action of rock pressure in deep underground mining. In-situ observation and numerical modeling test were carried out to investigate the redistribution patterns of stress in the rock surrounding a fully mechanized top-coal caving (FMTC) face of unsymmetrical disposal. The characteristics of mining-induced stress were open out based on the comparative and integrated analysis between in-situ observation and numerical simulation. There is a macro-stress shell (MSS) composed of high stress exists in the rock surrounding and it bears and transfers the loads of overlying strata by acting as the primary supporting system of forces. Its evolution is a mined-induced high stress developing and dynamically equilibrating process that form and influence the abutment pressure redistribution in spatial rocks during mining. Within the low-stress zone inside the stress shell, which only bears parts of the load from the lower-lying strata, has been proved by in-situ observation. The results show that the face is protected by the stress shell of the overlying surrounding rock and strata behaviors are under control of the stress shell.
Based on special mining and caving characteristics compared with other mining methods, the fully mechanized top-coal caving (FMTC) results in much distinctiveness of stress redistributing & developing that influence different characteristics on deep and superficial deformation laws of gates, support pressure changing laws of gates and stress redistribution laws of rock surrounding face. Maintenance and stability control of gates has been a difficult problem and impacts on safely mining, especially dissymmetrical disposal. Hence, large numbers of investigations have been done and developed a certain degree in the domain of abutment stress development and rock pressure control in recent years[1–10].