工作面“见方”期间冲击地压致灾因素分析及防治技术

Disaster-causing factors analysis and prevention technology of rockburst during square-forming period in working face

针对纳林河二号煤矿“见方”区域冲击事件频发的问题,分析了工作面静载、动静载量化叠加支承压力分布特征,得出了强冲击倾向性顶板特殊区域冲击机理,即:工作面采空区对宽煤柱一侧的工作面巷道施加静载,使影响区域煤岩体临近冲击状态;冲击临界状态煤岩体在强冲击倾向性顶板破断释放的大量弹性能的影响下,发生冲击地压灾害。据此设计了顶板爆破预裂和煤层大直径卸压钻孔方案,经对施工区域的效果进行检验发现,该方案可以降低工作面“见方”影响区域的冲击危险性,实现工作面的防冲安全。

In view of the frequent rock burst in the square-forming area in Nalinhe No.2 Coal Mine,the static load,dynamic and static load superposition of quantitative characteristics of abutment pressure distribution are analyzed.The rockburst mechanism is concluded for the special area of strong rockburst liability roof,that is in working face goaf,static load is applied to roadway along the wide coal pillar,bringing the coal and rock mass to the critical state of rock burst,which lead to rock burst disaster under the fierce elastic energy released from the breakage of strong rockburst liability roof.On this basis,the roof blasting pre-splitting and coal seam large diameter pressure relief drilling schemes are designed.The results of the test on the construction area show that,the rock burst risk of the square-forming working face in the affected area can be reduced and the rock burst in working face can be prevented.