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根据大断面厚顶煤巷道顶板的破坏特性,考虑了顶板围岩应力水平与支护荷载的影响,利用Hoek-Brown强度准则及其相关联的流动法则,构造出厚顶煤巷道顶板的冒落破坏机构。基于塑性力学中的上限分析方法,结合变分原理,推导得到了大跨度厚顶煤巷道顶板的冒落破坏机制,并以赵楼煤矿某巷道现场实践为例,分析了不同计算参数对顶板冒落破坏机制的影响。计算研究表明:随着岩体经验参数A、抗拉强度、抗压强度及支护荷载的增加,冒落体尺寸随之增大,而当岩体经验参数B、围岩应力及岩体重度增加时,冒落体尺寸则随之减小;冒落体尺寸代表了巷道顶板安全性能的大小,其尺寸越大,表明使巷道顶板发生冒落破坏所需外力功越多,顶板安全性能也越高;岩体经验参数B、围岩应力水平与支护荷载对顶板围岩破裂机制影响较为显著,参数B决定了冒落体的破裂形状,随着参数B的增加,冒落破裂迹线的曲率不断减小;增大支护阻力是提高顶板稳定性的有效途径,其研究结果可为大断面厚顶煤巷道支护设计提供一定的理论依据。
According to the failure characteristics of the roof of the thick section coal roadway, considering the influence of the surrounding rock stress level and the support load, Hoek-Brown strength criterion and its associated flow rule are used to construct the roof collapse of the thick roof coal roadway Destroy the body. Based on the upper bound analysis method in plastic mechanics combined with variational principle, the failure mechanism of the roof of long-span thick roof coal roadway was deduced. Based on the field practice of an alley in Zhaolou Coal Mine, the influence of different calculation parameters on roof caving, Fall under the influence of the damage mechanism. Computation studies show that with the increase of rock mass experience parameter A, tensile strength, compressive strength and supporting load, the size of the erector body increases. When the rock parameters B, surrounding rock stress and rock mass increase , The size of the falling body decreases. The size of the falling body represents the safety performance of the roadway roof. The larger its size, the more external force is required to cause the roadway roof to fall and the safety performance of the roof is also higher. The parameters of rock mass B, the stress level of surrounding rock and the supporting load influence the rupture mechanism of the surrounding rock more obviously. The parameter B determines the rupture shape of the rock falling body. As the parameter B increases, the curvature of the ruptured rupture curve decreases continuously Small; Increasing the support resistance is an effective way to improve the stability of the roof, and the results of the research can provide some theoretical basis for the support design of large cross-section thick roof coal roadway.