坚硬顶板切顶卸压围岩变形规律研究

Study on Deformation Law of Surrounding Rock in Hard Roof Cutting and Pressure Relief

为了进一步揭示坚硬顶板超前切顶卸压轨道下山的变形规律和保安煤柱的应力分布特征,以潞宁煤矿22115工作面开采为工程背景,利用相似材料模拟和现场实验,分析了坚硬顶板切顶轨道下山变形规律。结果表明:切顶可使采空区坚硬顶板在剪应力作用下沿着预制裂隙垮落,缩短悬顶长度,切断应力传递途径,有效缓解了保安煤柱承担的载荷。现场实践效果较好,巷道顶底板移近量约为320 mm,两帮移近量约为245 mm;切顶卸压技术是高应力坚硬顶板大变形巷道围岩控制有效途径之一。

In order to further reveal the deformation law and stress distribution characteristics of safety coal pillar of hard roof cutting and pressure relief track downhill,taking the 22115 working face of Luning coal mine as the engineering background,the deformation law of hard roof cutting and pressure relief track downhill was analyzed by using similar material simulation and field experiment.The results show that:cutting roof can make the hard roof of Goaf Collapse along the prefabricated cracks under the action of shear stress,shorten the length of suspended roof,cut off the stress transmission path,and effectively relieve the load of security coal pillar.The result of field practice is good,the approach of roof and floor is about 320 mm,and the approach of two sides is about 245 mm;roof cutting and pressure relief technology is one of the effective ways to control the surrounding rock of roadway with high stress and hard roof and large deformation.