Design of Support Parameters of Large-Section Open-Off Cut and Its Dynamic Mining Response Characteristics

Abstract

The open-off cut is an important place in coal mining. It is mainly used to install the relevant equipment of the working face and start mining from here. Its stability and safety play a very important role in the installation of the relevant equipment of the working face and the smooth progress of the mining. Compared with the mining roadway, the open-off cut of the working face has a larger span and is prone to caving accidents. Especially for large-section open-off cut, its roof stability control is a difficult problem for support. In order to solve the support design problem of 9106 large-section open-off cut under dynamic mining conditions in Hengsheng Coal Industry, the support parameters and support scheme of 9106 large-section open-off cut were designed by combining theoretical analysis, numerical simulation, and field monitoring. The dynamic response characteristics of 9106 large-section open-off cut in the mining process of adjacent l9301 working face were studied. The deformation and failure evolution law of 9106 large-section open-off cut were analyzed, and the support design scheme was applied to the engineering site. Among them, the maximum surface displacement of the two sides of the open-off cut is about 316 mm, the maximum surface displacement of the roof and floor is about 133 mm, the maximum displacement of the deep roof is 19 mm, the maximum displacement of the shallow roof is 30 mm, the stable value of the bolt force is about 6 MPa, and the stable value of the anchor cable force is about 9.3 MPa. It shows that the designed support scheme can meet the influence of the 9106 large-section open-off cut on the mining of the adjacent 9301 working face and ensure the stability of the surrounding rock of the 9106 large-section open-off cut.