变面长采场关键对接区围岩荷载传递演化的力学机制

The control of dynamic disasters such as rock burst, coal and gas outburst caused by mining in deep irregular working face has become a major technical problem in coal mining of China. Especially in the key activities interval of thirty meters range before and after the docking face of stope with variable length, the surrounding rock movement is frequent, and sudden increase of stress and superposition effect of high stress concentration.According to the increasingly prominent safety mining situation in the key docking area of stope with variable length, through the study methods of the rock mechanics test, theoretical analysis, numerical simulation, the similarity model test and field monitoring, the mechanical behavior characteristics of surrounding rock in the key docking area of stope with variable length under the state of three-dimensional loading is in-depth studied. Zonal evolutionary model of load transfer for surrounding rock in the key docking area is established.Spatial-temporal evolutionary law of surrounding rock unstable deformation in the key docking area is explored.The dynamic constitutive model and failure criterion of load transfer for surrounding rock in key docking area are established.The catastrophic mechanism of inducing subregional destruction of surrounding rock,stress transmission and dynamic load transfer have been found.Load transfer mechanism and mining response law of surrounding rock movement in the key docking area of stope with variable length are revealed.The goal of safe,efficient and sustainable exploitation for stope with variable length under the condition of mining disturbance in complex environment has been realized.

深部不规则工作面开采引发的冲击地压、煤与瓦斯突出等动力灾害治理问题已成为全国煤矿开采中的重大技术性难题，尤其在变面长采场对接面前后30m范围的关键对接区围岩活动频繁、应力骤然增大、高应力集中叠加效应显现。针对变面长采场关键对接区日益突出的安全开采形势，采用岩石力学试验、理论分析、数值模拟、相似模型试验和现场观测的方法，深入研究变面长采场关键对接区围岩三维施载状态下的力学显现特征，构建关键对接区围岩荷载传递的分区演化模式，探讨关键对接区围岩失稳变形的时空演变规律，确立关键对接区围岩荷载传递的动态本构模型与破坏准则，找出诱发围岩分区破坏、应力递变传接与荷载动态转移的灾变机理，揭示变面长采场关键对接区围岩运动的荷载传递机制与采动响应规律，实现复杂环境开采扰动条件下变长工作面安全高效可持续开采的目标。

变面长采场的普遍存在和开发困难、不规则开采诱发的围岩失稳和结构异化、变长工作面顶板防控机制的研究缺失和机械转化成为制约煤矿安全生产的重要影响因素。尤其在变面长采场对接面前后特定范围的关键活动区间围岩运动活跃，容易引发冲击地压、煤与瓦斯突出、顶板冒落与煤壁片帮等动力灾害事故。项目通过三年研究，圆满完成项目任务书规定的研究内容。项目分析了变面长采场关键对接区围岩变形破坏的静动态岩石微观、细观和宏观动力显现特征，提出了采场围岩静态弱扰动和动态强扰动两种岩石扰动破坏模式，掌握了静态弱扰动和动态强扰动条件下的岩石力学破坏特征。建立了变面长采场关键对接区围岩脆性破断的过应力本构方程与破坏准则，探明了关键对接区围岩三维施载状态的损伤破坏规律。弄清了变面长采场顶板围岩变形破坏的关键影响因素和指标权重，完成了对变面长采场回采期间围岩力学环境的综合评估和性态评价。建立了工作面斜长由小变大的突变型采场不同边界条件下的顶板结构模型，探究了变面长采场不同开采阶段的几何特征与力学成因。构建了变长工作面“三场三区三结构”的覆岩结构传递演化模型，提出了“两场两规律”的顶板分区破断效应。揭示了变面长采场围岩结构分区、应力分区、位移分区和裂隙分区变形失稳的时空演化规律，建立了变面长采场“四阶段三途径”的覆岩结构与荷载传递演化模式，获取了围岩荷载传递的矿压显现特征与动态响应机制，形成了复杂面长卸荷扰动条件下的煤层安全高效开采与顶板围岩控制理论。