开采上保护层对巨厚砾岩诱发冲击矿压的减冲机制分析

为研究开采上保护层对巨厚砾岩断裂诱发冲击的防治作用，根据跃进煤矿25采区的地质条件和采掘条件，将25110工作面下巷作为研究对象，从理论上分析了动静载叠加诱发冲击矿压的机制以及开采上保护层后的防冲原理，数值模拟研究了未开采上保护时和开采上保护层后在同等强度的动载扰动应力的影响下巷道底板的位移、速度、应力以及塑性区的变化规律，进行相似模拟试验研究了人工震源的作用下未开采上保护时和开采上保护层后巷道底板的加速度和动应力响应规律。结果表明，上保护层开采后能够有效地释放围岩内部的高应力，且采空区顶板自然垮落，形成的软弱松散岩层结构，能够更好地起到对动载扰动应力波的衰减作用，从而降低了冲击矿压发生的可能，一定程度上能够较好地防治冲击矿压。研究成果对巨厚砾岩下冲击矿压的防治具有一定指导意义。

Analysis of prevention mechanism of upper protective seam mining on rock rockburst induced by thick conglomerate

The purpose of this paper is to analyze the prevention effects of the upper protective seam mining on the rockburst induced by thick conglomerate. The gateway of 25110 coal face is used as the research object based on the geological and mining conditions of the mining area 25 in Yuejin Coal Mine. Theoretical analysis is used to study the mechanism of the rockburst induced by the dynamic-static loads and the theoretical basis of the prevention effects provided by the upper protective seam mining. Numerical simulation is performed to determine the change of displacement, velocity, stress and plastic distribution of the roadway floor under the same strength of dynamic disturbed stress; and simulation experiment is also conducted to study the response rules of acceleration and dynamic stress of the floor with artificial seismic source under the circumstances that when the upper protective seam was mined or not. The results show that the upper protective seam mining can effectively release the high stress inside the surrounding rocks and the soft and loose rock strata is formed after the roof rock strata of gob naturally caving, which can efficiently attenuate the dynamic disturbed stress wave and reduce the occurrence of rockburst. Therefore, the prevention effects are achieved to a certain extent when the upper protective seam mining is applied under thick conglomerate. Under the thick conglomerate rockburst prevention has certain guiding significance.