深部复杂应力下开采布置与采动应力协同演化机制研究

The coal seam strained condition and mechanical behavior become more complex with the increasing of mining depth. It makes the characteristic of stress distribution and dynamic evolution as a basic research theme to carry out mining design and surrounding rock control in deep mining. In order to explore the co-evolution mechanism among original crustal stress, roadway layout and mining-induced stress, the combined method of laboratory testing, physical modeling, numerical simulation, theoretical analysis and field measurement will be used. Especially, the optical fiber monitoring method monitoring will be used to monitor the strained condition in large-scale surrounding rock. The distributing characteristics and laws of 3-dimensional space mining-induced stress under the complex stress in deep mining are as the research objects. The surrounding rock stress distribution, deformation, fracture and evolution characteristics are emphatically analyzed under different lateral pressure coefficients and different mining roadway layout in deep mining. The relation model between crustal stress and roadway layout will be established, and the relationship between optical fiber sensing information and mining-induced stress evolution will be analyzed. The inverse analysis and 3-dimensional contour will be used to realize the visualization expression of surrounding rock stress distribution. Finally, the co-evolution mechanism among deep complex stress, mining roadway layout and mining-induced stress distribution and evolution characteristics are analyzed and revealed deeply. The study has an important theoretical guiding significance on the design of deep coal mining, roadway layout and surrounding rock control.

随开采深度增加，煤层受力状态及力学行为愈加复杂，使得采场应力分布及动态演化特征研究成为进行开采设计与围岩控制的基础性研究课题之一。项目针对原始地应力、巷道布置和采动应力协同演化机制这一科学命题，采用实验室测试与模拟、计算机数值模拟、理论分析和现场实测相结合的手段，将光缆感测方法用于大范围围岩受力状态连续监测中，对深部复杂应力下三维空间采动应力分布及动态演化特征进行研究，着重分析不同侧压系数、不同开采布置情况下，深部煤系地层采场围岩应力分布、变形破坏及动态演化机理。建立地应力分布与开采布置方式关系模型，分析光缆感测信息变化与采动应力演化的相关性，利用反演分析与等值线图像处理对采场空间围岩应力分布实现三维可视化表达，深入分析并揭示深部复杂应力、开采布置与采动应力分布及动态演化特征的协同演化机制。该研究对深部煤炭开采设计、巷道布置与围岩控制具有重要的理论指导意义。

课题针对原始地应力、巷道布置和采动应力协同演化机制这一科学命题，采用实验室测试与模拟、计算机数值模拟、理论分析和现场实测相结合的手段，对深部复杂应力下三维空间采动应力分布及动态演化特征进行了研究，着重分析了不同开采布置情况下，深部煤系地层的采场围岩应力分布、变形破坏及动态演化机理，并以淮南矿区深部开采为工程背景进行了工程应用。.（1）开展岩石动、静态力学测试及室内相似模拟实验研究，通过室内相似模拟实验分析得出沿工作面布置方向工作面围岩应力分布区域范围，分为未受采动影响区、应力增高区、卸压区、压力增长区、压实区。.（2）利用数值模拟方法，对单一煤层开采、单一煤层重复采动条件下开采及多煤层重复采动条件下开采的模拟分析，得到了多种采动影响下的采场围岩应力分布、围岩移动变形及围岩变形破坏特征。.（3）结合室内相似模拟实验，进行了电法及光纤传感测试技术综合实验研究。采用分布式光纤传感技术和并行电法测试，分析了单层及双层开采条件下煤层顶底板围岩的应变分布及变化特征，获得了煤层顶底板渐进变形、破坏的全过程变化规律。.（4）开展井下工作面原位测试，采用分布式光纤感知技术、并行电法测试技术及钻孔应力解除法，利用运顺断面、轨顺断面以及煤上山断面监测孔实施连续监测，对深井采动空间围岩应力场及其采动特征进行综合观测，获得了工作面开采过程中采场围岩应力空间分布及其动态特征。煤层在采动过程中超前支撑压力的影响范围可达170m，明显影响范围70～90m左右，剧烈影响范围约25～35m左右，超前支承压力分布在煤壁前方4～12m；采动在上、下顺槽及上山断面的巷道空间内影响的范围有一定的差异，且发现断层受采动影响的显著变形特征。.（5）结合数值模拟及实测数据结果，开展了采动空间围岩应力场演化特征研究，获得了工作面原始应力、开采过程中采场围岩应力空间分布及其动态演化特征，为深部采掘巷道及采场合理布置提供有效的测试及研究方法。