Abstract:
With the increase of coal mining depth,the geological conditions encountered in the process of roadway excavation are becoming more and more complex. Especially in the bad geological bodies such as fracture zone,the problems of surrounding rock crushing and roof caving bring great challenges to the safety and rapid excavation of roadway. In this study,the 240 return air roadway,auxiliary transportation roadway and belt transportation roadway in the north second mining area of Hancheng Mining Co.,Ltd.,were taken as the engineering background. In view of the problems of surrounding rock crushing and roof caving encountered by TBM (Tunnel Boring Machine) in the process of fracture zone excavation,the key technology of surrounding rock control was studied. Firstly,the engineering geological conditions of the three roadways are analyzed,and the main reasons for the breakage of the surrounding rock of the roadway are determined. Based on the theory of geotechnical mechanics,the grouting reinforcement scheme of roadway surrounding rock is proposed,and the grouting material,grouting parameters and grouting reinforcement scheme are optimized. The field industrial test results show that the grouting reinforcement significantly improves the stability of the surrounding rock mass of the roadway,reduces the safety accident and support cost,and significantly improves the tunneling speed.