煤矿冲击地压的推采速度效应及其动态调控
Effect of advance speed on rock burst in coal mines and its dynamic control method
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摘要: 针对采煤工作面冲击地压存在推采速度效应问题,通过案例与微震监测数据分析,探讨了采场推采模式及速度与冲击地压的关系,揭示了采场推采速度效应产生机制,并通过对类似工作面微震特征的分析,建立了采场推采速度效应动态调控的方法。研究表明:回采工作面冲击地压危险性与采场推采模式及速度具有相关性,其中高速推采、非匀速推采易诱发冲击地压;高速推采造成多顶板势能转化和多煤层应变能均衡释放,非匀速推采导致煤层应变能集中释放;基于微震响应特征构建的采场推采速度效应动态调控方法具有良好的实用性。Abstract: This paper investigates the effect of advancing speed of working face on the rockbursts in working faces by means of case studies and microseismic monitoring data analysis. Its mechanism is then revealed based on the identifi- cation of relationships between rockburst and advancing mode or speed. A dynamic control method for the advancing speed effect is presented through analyzing the microseismic characteristics of similar working faces. The results show that the rockburst hazard of working faces is associated with the advancing mode or speed. Two advancing modes,high speed and inconstant speed,tend to induce rockbursts in working faces. Advancing at a high speed can lead to the transformation of potential energy in roof strata and the release of strain energy in coal seams. Advancing at an incon- stant speed can lead to the localized release of strain energy in coal seams. A dynamic method for controlling advancing speed effect is presented based on microseismic response characteristics,and its successful applications in a number of coal mines demonstrate that it can provide a guideline for the active prevention and control of rockburst hazards in deep mining.