Research on Mechanisms and Control Measures of Surrounding Rock Disaster in Large Section Roadway with Top Coal under the Influence of Tectonic Stress

Abstract

Based on the research background of large section roadway with top coal (LSRTC) in thick coal seam mining in Wangzhuang Coal Mine, Shanxi Province, China, catastrophe characteristics of the surrounding rock of the LSRTC were investigated and summarized. Based on the principle of damage mechanics, the critical size discriminant of the LSRTC was deduced, and the induction mechanism of section size effect and tectonic stress effect on the roadway surrounding rock disaster was revealed. Accordingly, the roadway surrounding rock control principle with the basic idea of “stabilizing and controlling top coal, reconstructing the coal wall, and limiting floor heave” was put forward, and the roadway surrounding rock stability control countermeasures with the core technology of “strong pressure support for roof + grouting reinforcement for two sides + bolt barrier for floor angle” were developed, which solved the surrounding rock control problem of the LSRTC under the action of tectonic stress and provided a useful reference for the difficult problem of roadway surrounding rock control under similar conditions.

Failure properties of roadway with extra-thick coal seams and its control techniques

“…In order to research the surrounding rock stress evolution laws and deformation features of the roadway with thick top coal, the similarity models [ 2 ], the Hoek-Brown failure criterion [ 3 ], the field measurement and the numerical simulation methods have been applied by many scholars. Based on the relevant research results, it is well known that the superimposed mining stress which induced by the large mining thickness of the coal seams and the intense movement of the overlying strata could aggravate the deformation and instability failure of the roadway with thick coal roof [ 4 ], the supporting system and its efficiency will gradually decrease [ 5 , 6 ] during this process, and the asymmetric floor heave and significant deformation was more easily appear for gob side roadway in extra-thick Coal Seams [ [7] , [8] , [9] ]. In order to control the surrounding rock deformation of the roadway with extra-thick coal seam, the dense combined supports have to be applied in roadway construction on site, which significantly reducing the driving efficiency and leading to the technical problem of mining proportion imbalance in the mine [ 10 ].…”