采掘扰动围岩三维压力拱演化特征及主动调控机制研究

For rock self-bearing theory lags the practice at present, it is of important theoretical and practical value to research on the forming arch conditions, morphological parameters, evolution characteristics and regulatory mechanisms of the 3D pressure-arch in the surrounding rock of the roadway and mining field by using the methods such as theoretical analysis, laboratory experiments, numerical simulation and site monitoring. The main contents are as follows: Firstly, Based on the micromechanics and energy principle, the law of strain energy release in the disturbance surrounding rock was researched, the boundary and morphological parameters of the 3D pressure-arch is defined, and the forming arch conditions and evolution characteristics of the pressure-arch in the surrounding rocks were revealed with the continued excavation progress. Secondly, the stable conditions, the failure criterion and key parts of the pressure-arch were given based on information entropy and system catastrophe theory. Thirdly, based on the coordinated relationships of the primary and secondary pressure-arch structures, the mechanism of self-supporting and transfer external loads of the pressure-arch were analyzed, the self-stability control and active regulation mechanisms of the pressure-arch during the mining were explained. All these above mentioned were to enrich and develop the existing rock self-bearing theory, and to provide theoretical basis and technical support for the engineering practice.

针对围岩承载理论滞后于工程实践的现状，采用理论分析、室内试验、数值模拟与现场监测相结合的研究方法，对采掘扰动巷道及采场顶板围岩三维压力拱，分别进行成拱条件、形态参数表征、力学演化行为和主动调控机制的研究，具有重要理论意义和实用价值。 主要研究内容：（1）基于细观力学和能量原理，进行采掘扰动围岩应变能释放规律研究，定义三维压力拱边界及形态参数，探究压力拱成拱条件、揭示随开挖卸载围岩压力多次成拱的力学演化特征。（2）基于信息熵和系统突变理论，提出压力拱自稳条件及失稳的判据，确定压力拱受力关键部位及其破坏模式。（3）基于压力拱主、次承载结构相互协调关系，揭示压力拱结构自承载与传递外载的力学机理，阐释采掘扰动围岩稳定和人为主动调控机制。 项目研究以期丰富和发展现有围岩承载理论体系，为现场实践提供理论依据和技术支撑。

针对扰动围岩承载理论滞后于工程实践的现状，采用理论分析、室内试验、数值模拟与现场监测相结合的研究方法，对采掘扰动巷道及采场顶板围岩三维压力拱，分别进行成拱条件、形态参数表征、力学演化行为和主动调控机制的研究，具有重要的理论意义和工程实用价值。主要研究成果：（1）实现了集中荷载和均布荷载作用下，岩板变形断裂铰接成拱失稳破坏的试验研究。基于细观力学和能量原理，自行编写岩板加载颗粒流程序，验证了实验结果并对影响岩板失稳破坏的各个因素进行了敏感性分析。（2）定义了压力拱边界及形态参数，基于应变能熵，揭示了连拱隧道分步开挖扰动围岩应变能释放规律；提出了隧道压力成拱条件，揭示了隧道开挖扰动围岩压力多次成拱的力学演化特征；基于红外成像试验，揭示了连拱隧道分步开挖产生的围岩压力偏态效应。（3）基于系统突变理论，建立了浅埋超长工作面裂隙梁力学模型，给出了结构屈曲失稳的临界载荷、挠度及突跳下沉量。构建了采场压力拱结构力学模型，确定了压力拱受力关键部位及存在拉伸破坏，压缩破坏及剪切破坏三种破坏模式。（4）结合实际工程，基于压力拱主、次承载结构相互协调关系，构建了近场覆岩关键块对称压力拱、台阶压力拱、回转压力拱及远场覆岩压力拱结构力学模型，解析推导了压力拱结构稳定性力学判据及承载能力表征指标。（5）自主研发了组合式多功能伺服控制加载相似模拟实验台，利用相似模拟试验和数值模拟，验证分析了近场及远场覆岩复合压力拱演化特征，揭示了采场覆岩压力拱演化与能量场迁移及耗散耦合机制，阐释了采掘扰动围岩人为主动调控的机理。（6）自主研发了实现扭矩与轴力解耦的锚索拉拔试验装置；揭示了锚固钢筋在拉拔过程中锚固体破坏机理，建立了锚固钢筋在受剪过程中剪力与轴力关系，并对锚固节理面抗剪性能影响参数进行了敏感性分析。项目研究丰富和发展了现有围岩承载理论体系，为现场实践提供了理论依据和技术支撑。