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为合理评价开采区域的冲击矿压危险程度,分析了岩-煤-岩组合体受载过程中各部分的位移、加速度、刚度及能量等物理参量的演化规律,提出了以煤体峰值后刚度和岩石卸载刚度为基本参量的组合体稳定破坏和失稳破坏的判别条件。结果表明,岩-煤-岩组合体的破坏状态由其中的煤体峰后刚度及顶底板岩石刚度k1,k2对比关系决定,峰值后卸载至煤体曲线刚度变化率满足21 2 1 2k k m/[(k k)u]的点S后,系统不再维持平衡状态,由稳定破坏转为失稳破坏。提出了采用岩-煤-岩组合体破坏过程中顶底板释放和煤体消耗的能量之比参数作为煤岩组合条件下的冲击倾向性评价指标,并对2个矿区7个地点实际样品进行了冲击倾向性测试结果对比分析,其中有2个取样地点的顶底板会影响煤体冲击倾向性评价结果,试验结果表明,采用岩-煤-岩组合体模型比单纯煤样测试结果能更好地反映现场围岩实际条件对冲击危险的影响程度。
In order to reasonably evaluate the danger of rock burst in the mining area, the evolution law of the physical parameters such as displacement, acceleration, stiffness and energy of the rock-coal-rock composite during its loading process is analyzed. The post-peak stiffness And rock unloading stiffness as the basic parameters of the stability of the combination of stability and failure to determine the conditions of failure. The results show that the failure state of the rock-coal-rock composite is determined by the post-peak stiffness of the coal body and the rock-bottom rock stiffness k1, k2, and the rate of change of the stiffness after unloading to the coal body peak satisfies 21 2 1 2k km / After the point S of [(kk) u], the system will no longer maintain the equilibrium state and will be transformed from stable failure to destabilized failure. The parameter of energy ratio of top and bottom slab release and coal consumption in the process of rock-coal-rock assembly destruction is proposed as an index to evaluate the impact propensity under coal-rock combination conditions. Actual samples from 7 locations in 2 mining areas Comparison of the results of impact propensity test results, including the top and bottom of two sampling sites will affect the impact evaluation of coal, the results show that using rock-coal-rock combination model than the simple coal sample test results better Reflect the impact of the actual conditions of the surrounding rock on the impact risk.