Research on surrounding rock control technology of roof cutting and pressure relieving for roadside filling in gob-side entry retaining of large mining height panel

This article takes the transportation channel of the 2507 working face as the engineering background to carry out the analysis of the surrounding rock failure mechanism of the roadside filling in gob-side entry retaining of large mining height panel, and summarizes three common forms of instability failure of the filling wall. The method and idea of using a combination of "strengthened support + roof cutting pressure relief" to control the surrounding rock of gob-side entry retaining of roadside filling is determined. In theory, the optimal range of roof cutting height and roof cutting angle was obtained, and an innovative introduction of deviatoric stress analysis index was made. Numerical simulation research was conducted on the distribution characteristics of deviatoric stress in the surrounding rock of the gob-side entry retaining under different roof cutting heights, roof cutting angles, and wall width conditions. The optimal parameters for roof cutting and pressure relief of the gob-side entry retaining of roadside filling in the high mining face were obtained. The on-site engineering practice shows that after adopting the joint control technology of "strengthening support + roof cutting pressure relief", the displacement of the surrounding rock of the retained roadway, the force of the anchor cable, and the bearing capacity of the flexible formwork wall are all within the normal range, ensuring that the retained roadway can continue to be used by the next working face.