深部高应力储能岩石真实强度及诱导释能研究

The residual stress is often found in the deep and high stress tectonic region. Its macroscopic performance is closely related to the microstructure of the rock. It is meaningful to study the mechanism of residual stress and its effect on the true strength of rock. Firstly, the rock microstructure test is carried out. Based on this, the microstructural characterization of residual stress is established to reveal its microstructure mechanism. Secondly, the elastic strain energy in rock is calculated by residual stress test. In this way, the relationship between the state of rock energy storage and the residual stress can be established. Thirdly, true strength test of rock is designed to obtain the relationship between the nominal strength and residual stress vector. Then the true strength calculation and energy storage rock characterization can be established. After that, the experiment of unloading mechanical behavior of energy storage rock is carried out using the true triaxial machine. Through the energy analysis of rock deformation and failure process, the mechanism of energy conversion process of damage and fracture can be revealed. Finally, the activation of locked energy under unloading, along with the mechanism of synergistic disaster induced by multisource energy can be revealed. The results are useful for guiding the controllable release of energy.

针对深部高应力构造区域地质体存在残余应力的地质力学现象，将区域残余应力的宏观表现与岩石微观组构相联系，研究残余应力的微观结构机制及其影响下的岩石真实强度的表征，以及储能岩石能量释放的灾变机制与诱导可控释能机理。以岩石微观组构测试为前提，建立岩石残余应力的显微组构表征，揭示岩石残余应力产生的微观结构机制；以岩体正交异性弹性理论为基础，进行岩石残余应力检测，并由残余应力计算封闭弹性应变能，建立岩石储能状态与残余应力的对应关系；设计考虑残余应力的储能岩石真实强度测试实验，揭示实验名义强度与残余应力矢量的关系，建立储能岩石真实强度的计算和表征方法；设计真三轴条件下储能岩石卸荷力学行为实验，通过对岩石变形破坏过程的能量分析，揭示储能岩石损伤破裂的能量转化过程机制，以及卸荷条件下岩石储能的激活过程及与外部输入能量的协同致灾及诱导可控释能机理。

针对特殊构造区域地质体存在封闭应力的地质力学现象，为揭示岩石封闭应力的存在形式，通过EBSD及光学显微镜进行岩石微观表征，确定存在满足XRD封闭应力测量要求测区；以岩体正交异性弹性理论为基础，利用X射线衍射仪，对含石英脉硅质板岩样品采用sin2ψ法测量并计算封闭应力的量值，确定封闭应力的主应力；依据微观测试与封闭应力测试结果相结合分析封闭应力产生机制。主要结论如下：依据微观测试结果分析可得岩石在毫米范围内存在均质、且粒径较小区域，满足XRD应力测定统计量要求；含石英脉板岩样品确定石英为标定矿物，获取不同ψ和φ下（324）晶面衍射图谱，其衍射峰偏移方向具有一致性，证明待测样品存在封闭应力；石英脉XRD测得封闭应力主应力均为压应力，大小在10~33MPa之间，最大主应力平行脉体走向，最小主应力垂直脉体走向；石英脉中小角晶界及孪晶界含量均较高，分析岩石中应力封存与岩石中矿物晶体非均质特性、塑性变形相关。所提出的封闭应力的测量方法可为后续开展不同类型岩石封闭应力的观测和相关研究提供参考。