复杂岩层大断面硐室群围岩破坏机理及控制

针对复杂岩层巷道交叉点高应力集中区四周硐室群开挖围岩稳定性控制和支护技术等难题,通过对现场取样测试硐室群围岩物理力学参数、黏土矿物成分和松动圈大小,分析了赵庄煤矿三盘区带式输送机头硐室群及周边巷道围岩变形破坏特征和机理,表明硐室帮部煤柱和底板围岩是加固支护重点。利用FLAC3D数值模拟软件分析了硐室群开挖对硐室群及周边巷道围岩应力分布和塑性区分布范围的影响。基于理论分析和数值模拟提出了硐室及周边20 m范围内巷道围岩"强柱固底"的加固支护方案。现场工业试验表明,加固支护后,硐室群及周边巷道围岩变形得到了有效控制,围岩内部裂隙基本被浆液填充,60 d内围岩顶底板和两帮最大移近量分别为30 mm和50 mm,达到了理想的加固支护效果。

Failure mechanism of surrounding rock of large section chambers in complex rock formations and its control

The stability control and support of surrounding rocks in the chambers around the crossing points of roadways of complex rock formations with a high stress concentration are difficult,but yet significant.To solve the problems,this research analyses the characteristics and mechanism of deformation and failure of surrounding rocks in the chambers of belt conveyer of the third panel in Zhaozhuang Coal Mine in China and the roadways surrounding them by testing the physical and mechanical parameters,clay mineral composition and the thickness of loose circle of the surrounding rocks.The results indicate that the support of the surrounding rocks in the coal pillar and floor of the chambers are of the most importance.In addition,the influence of excavation on the distribution of stress and the plastic zones of the surrounding rocks is analyzed by FLAC3D numerical simulation software.Based on theoretical analysis and numerical simulation,the supporting method entitled “reinforced support of coal pillar and floor” is proposed for the chambers and roadways within 20 m.Field experiments show that the desired reinforcing results can be achieved by utilizing the supporting method proposed.The deformation of surrounding rock is effectively controlled;Internal cracks are filled with grout;The maximum deformation of roof,floor and siding walls is within 30 mm and 50 mm during 60 days.