厚而坚硬顶板破断诱发冲击地压的机理及其防治方法

The Mechanism and Prevention of Rock Burst Induced by Thick and Hard Roof Breakage

基于动静载荷叠加诱发冲击地压机理,以开采煤层上方厚而坚硬顶板为研究对象,建立了工作面回采和沿空巷道顶板破断诱发冲击地压力学模型,并推导出顶板破断引起平均应力和动载荷增加的理论计算公式,以及顶板张拉破坏和剪切破坏判定公式。现场钻孔应力计监测结果和理论计算结果对比表明,利用该力学模型可以比较准确地计算动载荷和应力增量,且顶板厚度、支撑宽度和断裂线在煤体内深度是影响动载荷大小的关键因素。通过对该力学模型的讨论,指出多种有效防治冲击地压的方法。该力学模型的构建为冲击地压危险程度的判别和防治提供了一种新的思路。

Based on the mechanism of static and dynamic load superimposed induced rock burst,taking a thick and hard roof above the coal seam.As the research object,the mechanical model that working face recover^^and roadw-ay along the roof breaking induced rock burst was established,deduced the theoretical for^nula that the increase of average stress and dynamic load caused by roof breakage,and the formula of judgment of roof tensile failure and shear failure.The comparison between the monitoring results of borehole stress meter and the theoretical calculation results showed that the dynamic load and stress increment can be calculated accurately by using this mechanical model,the roof thickness,support width and fracture line is the key factor affecting the dynamic load.Through the discussion of this mechanical model,several effective methods for preventing and controlling impact pressure were pointed out.The construction of the mechanical model provided a new way to identify and prevent the impact of rock burst.