弱胶结地层劣化诱发硬岩破断失稳效应下的顶板动力溃砂机制

采场顶板溃水溃砂和强矿压显现并发灾害是严重制约黄陇、宁东煤炭基地资源开发的难题，弱胶结地层遇水劣化诱发上方硬岩破断和下方基本顶失稳产生的动力溃砂机制是解决该灾害防控技术瓶颈的关键。项目采用XRD、XRF、SEM、显微CT、三维数据重构、GCTS岩石力学测试等手段，综合钻孔地球物理测井结果，探寻弱胶结地层劣化性质对影响因素的反馈特征及响应关系；基于相似模拟和数值模拟，统计构建硬岩下方支承压力和基本顶上方载荷分布对弱胶结地层劣化响应规律的表达函数，采用灰色关联度和Pearson相关系数，实现响应规律主控因素的关联和表征；构建“下基本顶-中弱胶结地层-上硬岩层”结构力学模型，分析硬岩挠度、弯矩、内力和应变能，探讨硬岩破断和基本顶失稳作用下劣化弱胶结地层性质、溃涌的动力和通道形成机制；研究动力、通道宽度和粒径对溃砂的影响规律。项目旨在揭示弱胶结地层劣化诱发的顶板动力溃砂机制，有效指导灾害防控。

The water and sand inrush of stope roof and the concurrent disaster of strong ground pressure behavior are the difficult problems that seriously restrict the resource development of Huanglong and Ningdong coal bases. The mechanism of dynamic sand inrush generated by the fracture of the upper hard rock and the instability of lower main roof caused by the water deterioration of weakly cemented strata is the key to solve the technical bottleneck of prevention and control of disaster. The project uses XRD, XRF, SEM, micro-CT, 3D-data reconstruction, rock mechanics based on the GCTS testing systems and other means to explore the feedback characteristics and response relationship of the deterioration properties of weakly cemented strata to the influencing factors by integrating the results of borehole geophysical logging. Based on the similarity simulation and numerical simulation, the expression function of abutment pressure under the hard rock and load distribution above the main roof on the response law of the deterioration of weakly cemented strata is established. Grey correlation degree and Pearson correlation coefficient are used to achieve the correlation and characterization of the main controlling factors of the response law. The structural mechanics model of "lower main roof - middle weakly cemented strata - upper hard rock" is constructed to analyze the deflection, bending moment, internal force and strain energy of hard rock, and to explore the properties of deteriorated weakly cemented strata, the dynamic force of sand inrush and the formation mechanism of channel under the action of the fracture of hard rock and the instability of main roof. The influence of dynamic force, channel width and particle size on sand inrush is studied. The project aims to reveal the mechanism of roof dynamic sand inrush induced by the deterioration of weakly cemented strata and effectively guide disaster prevention and control.