条带式Wongawilli开采煤柱失稳覆岩破坏分析

为研究条带式Wongawilli开采煤柱失稳覆岩破坏机理及岩层移动特征,结合赵屋煤矿15号煤连采一区地质采矿条件,采用理论分析、现场实测、公式计算及相似模拟相结合的方法,建立了条带式Wongawilli开采煤柱系统模型,分析了煤柱失稳机理及其对覆岩的影响。研究表明:条带式Wongawilli煤柱系统中,个别损害或者不规则(有尖角)煤柱在矿山压力及地下水侵泡等不良因素的共同作用下可能发生破坏失稳,进而引发相邻煤柱失稳,产生"多米诺"效应,从而导致整个煤柱系统失效;煤柱一旦发生失稳,开采工作面由非充分采动转化为充分采动,加剧覆岩破坏,导致地表塌陷。

Overburden failure induced by instability of coal pillar in strip Wongawilli mining

In order to study the failure mechanism and movement characteristics of overburden induced by coal pillar instability,the first continuously-extraction area of No.15 coal seam in Zhaowu Mine was taken as a geological model,and theoretical analysis,similar simulation,site measurement and formula calculation were combined to build a systematic model in strip Wongawilli mining,and the coal pillar instability and its effect on overburden failure were analyzed.The results show that in the pillar system of strip Wongawilli mining,some damaged or irregular pillars would become instable under the coupling effect of mining pressure,ground water immersion and other unfavorable factors,correspondingly,relevant pillars would be affected and become instable.Therefore,“Domino effect” occurred and the whole pillar system invalidated.Overburden failure was aggravated by pillars instability,the mining condition transformed insufficient mining stage to sufficient mining stage,which resulted in surface subsidence.