覆岩结构对松散承压含水层下采煤压架突水的影响研究

Overburden structure influence to support crushing and water inrush during mining under unconsolidated confined aquifer

针对松散承压含水层下采煤压架突水灾害问题,采用数值模拟和相似材料模拟手段,就松散承压含水层下采煤基岩厚度、硬岩层层位及硬岩层的不同组合特征等覆岩结构因素对压架突水灾害的影响进行了研究。结果表明:在松散承压含水层载荷传递作用较大的情况下,压架突水灾害的发生主要与覆岩结构有关,当基岩越薄、距离煤层10倍采高以内的顶板中存在巨厚硬岩层且距离煤层最近的硬岩层厚度越大时,覆岩越易发生整体破断,引发工作面压架突水灾害。上述影响规律得到了祁东煤矿7114和7112工作面开采实践的验证。根据压架突水灾害发生的覆岩结构条件,可以在采前对压架突水危险区域进行预测,从而为采场压架突水灾害的防治提供依据。

In this paper, in view of the support crushing and water inrush disaster when mining under unconsolidated confined aquifer, numerical and physical simulations were used to study the influence of overburden thickness, key stratum location and structural combination characteristics, etc., on support crushing and water inrush disaster. The results show that under the remarkable load transfer faction of unconsolidated confined aquifer, support crushing and water inrush disaster is mainly related to the overburden structure. The thinner the thickness of bedrock is, and the thicker the first key stratum above coal seam is, the more easily the integral breakage of overburden occurs if the super-thick stratum exits within 10 times mining height distance above coal seam, which may easily induce support crushing and water inrush disaster in coal face. Above has been validated at No.7114 and No.7112 working faces in Qidong Coal Mine. Based on the overburden structure, the dangerous area of support crushing and water inrush can be predicted before coal mining, which may provide a basis for such disaster prevention.