针对煤矿矿震分类缺乏定量化指标、矿震传播规律不清楚、危险性矿震难以判别等问题，综合采用数值模拟、理论分析及现场实测的方法，对煤矿矿震进行了分类，通过UDEC数值模拟再现了震动波在节理岩体中的传播过程，结合微震监测数据，统计分析了矿震震动波传播过程中质点峰值速度和震动波能量的衰减规律，初步探讨了危险性矿震判别方法。结果表明：煤矿矿震可分为采动破裂型、巨厚覆岩型和高能矿震型3种，其中高能矿震型又可细分为煤体内爆型、顶板失稳型和断层活化型。根据矿震是否对井下人员或设备造成危害，又可将矿震分为正常矿震和危险性矿震2大类。矿震震动波传播受多种因素影响，煤岩体中的不连续面对震动波传播作用明显。揭示了不连续面对震动波应力传递的阻断机制：当震动波传递的应力与原岩应力叠加超过不连续面强度时，不连续面发生破坏，出现一定位移，介质的不连续性阻断了震动波应力传播。矿震传播过程中，质点峰值速度与震动波能量之间具有内在联系，峰值速度、能量均与传播距离呈负指数型关系。实测表明：某矿区实体煤区域和采空区区域的质点震动速度吸收系数分别为0.003 75和0.007 6，震动波能量吸收系数分别为0.007 5、0.015 2，2种区域内震动波衰减差异明显，不连续面对震动波传播影响显著，验证了数值模拟的正确性。

Aiming at the problems of the lack of quantitative indicators for the classification of coal mine tremor,the unclear propagation law of mine tremor,and the difficulty of identifying dangerous mine tremor. Methods of numerical simulation,theoretical analysis and field measurement are used in this study. Types of mine tremor are proposed. Through UDEC numerical simulation,the propagation process of shock wave in jointed rock masses is reproduced. Combined with micro-seismic monitoring data,the attenuation law of the peak velocity of the particle and the energy of the shock wave are analyzed during the propagation process. And the method of distinguishing dangerous mine tremor is discussed. The results show that:coal mine tremor can be divided into three types:induced by mining fracture,induced by broken of huge overlying strata and high-energy mine tremor. The high-energy mine tremor can be subdivided into failure of coal,roof instability,and fault activation. According to whether or not mine tremor is destructive,mine tremor can be divided into two categories:normal mine tremor and dangerous mine tremor. The propagation of shock wave in mines is affected by many factors,and the discontinuities in coal and rock masses have significant effects on the propagation of shock wave. The blocking mechanism of shock wave stress transmission on the discontinuous surface has been revealed:when the superposition of the stress transmitted by shock wave and original stress exceeds the strength of discontinuity surface,the discontinuity surface will failure and a certain displacement will occur,and the propagation of shock wave will be blocked because of discontinuity of the medium. During the propagation process of a mine tremor,there is an internal connection between the peak velocity of the particle and the energy of the shock wave,and there is a negative exponential relationship between the peak velocity or energy with the propagation distance. The velocity absorption coefficients of the solid coal area and the goaf area are 0.003 75 and 0.007 6,respectively,and the energy absorption coefficients are 0.007 5 and 0.015 2,respectively. There are obvious differences in the attenuation of shock wave in the two areas. The discontinuity has a significant impact on the propagation of shock waves,which verifies the correctness of the numerical simulation.

0 引言

1 煤矿矿震类型

2 矿震震动波传播数值模拟

   2.1 数值模型与方案

   2.2 震动波传播应力响应过程

   2.3 不连续面的应力阻断机制

3 矿震传播能量衰减规律与实测

   3.1 震动波能量衰减规律

   3.2 现场实测

4 结论