Surrounding rock deformation control of asymmetrical roadway in deep three-soft coal seam: a case study

摘要

Surrounding rock deformation control (SRDC) of roadways in deep three-soft coal seams (TCSs) is a significant technological difficulty that hinders the safety and high-efficiency mining of coal mines. According to the specific mining geological conditions of Liuquan Coal Mine, this study analyzed the deformation characteristics of surrounding rock under an original support scheme for the headgate (a typical asymmetrical roadway) in #3307 coalface. The analysis results showed that the surrounding rock displayed whole section deformation characteristics. The maximum value of roof subsidence was 369 mm, the maximum cumulative deformation value of the two sidewalls was 784 mm, and the maximum value of floor heave was 386 mm. On this basis, the mechanical structure models (roof, sidewall, and floor) of the roadway surrounding rock (RSR) were constructed, and the deformation mechanisms of the RSR in the TCS were revealed. Then, the principles for the SRDC of this asymmetrical roadway in deep TCS were proposed, the support parameters of the headgate were optimized, and the numerical simulation analysis of support effect was also performed using FLAC(2D) software. Engineering application results indicated that the surrounding rock deformation of the headgate was better controlled. Under the optimized scheme, the maximum value of roof subsidence was 50 mm, the maximum cumulative deformation value of two sidewalls was 120 mm, and the maximum value of floor heave was 80 mm, which verified the feasibility of the optimized support parameters.