厚层坚硬顶板巷道围岩冲击破坏力学分析及解危方案

Mechanical analysis of impact failure of surrounding rocks of roadway failure and the countermeasure of danger relief in condition of thick and hard roof

以冲击地压矿井为工程背景,分析了厚层坚硬顶板对煤岩动力灾害的力学作用,依据煤岩层赋存地质资料,基于FLAC3D建立了简化数值模型,模拟分析了工作面回采过程中厚层坚硬顶板条件下采场应力场分布特征,探讨了围岩冲击破坏卸压解危措施。研究结果表明:厚而坚硬顶板不易破坏垮落,易对工作面造成应力集中,且厚而坚硬顶板的失稳破断会释放巨大能量,产生的动载对巷道稳定极为不利;除了采空区外,其他区域的水平应力、最大主应力与最小主应力全部处于较高状态,尤其超前工作面80 m范围内应力集中程度最高。该研究可明确采场煤岩体的应力集中区域,为巷道围岩卸压解危措施提供理论基础。

Taking the typical coal bumps area as the engineering background,the paper analyzes the mechanical effect of the thick and hard roof on the dynamic disaster of coal and rock,and based on the geological data of the coal and rock stratum,establishes the simplified numerical model by using FLAC3 Dsoftware,the distribution characteristics of stope stress field with mining process are analyzed in condition of thick and hard roof.The measure of danger relief with stress releasing for impact failure of surrounding rock was discussed.The results show that the enormous thickness conglomerate is hard,dense and high self-weight,not easy to fracture and collapse,easy to cause stress concentration in the working face.And the fracture of the enormous thickness conglomerate can release huge energy quickly,which is disadvantageous to the safety of the working face.The horizontal stress,the maximum principal stress and the minimum principal stress in other areas of the stope are all in the high state,especially the stress concentration is the highest within 80 meters of the advanced working face.The study can directly grasp the stress concentration area of coal and rock mass in Stope,which provides theoretical basis for the measure of danger relief with stress releasing of surrounding rock of roadway.