坚硬顶板切顶留巷参数优化与围岩非对称支护技术研究OA

The problems of strong dynamic pressure and asymmetric large deformation control faced by gob-side entry retaining under hard roof were studied.The optimization of roof cutting and pressure relief parameters was conducted by combining theoretical analysis,numerical simulation and field tests.The optimal parameter combination with a roof cutting height of 15 m and a roof cutting angle of 15° was determined.Two evaluation indicators,namely height pressure relief efficiency(ηH)and angle pressure relief efficiency(ηω),were established,and the critical thresholds for parameter optimization were quantitatively identified.Sensitivity analysis was performed,and it was revealed that the roof cutting height was the dominant factor controlling the stress redistribution of surrounding rock after roof cutting.The rotation path of rock blocks was optimized by the roof cutting angle,and the stability of surrounding rock was finely adjusted accordingly.A collaborative support system was proposed according to characteristics of asymmetric stress field formed after roof cutting.Theoretical basis engineering demonstration were provided for gob-side entry retaining under similar geological conditions.