动静组合加载下深部隧道围岩各向异性动力特性及灾变机理研究

Deep rock engineering is related in transportation, mining, water resources and hydropower engineering, rock deformation and failure modes have a significant nonlinearity and strong dynamic characteristics due to complex geological environment with high field stress, high temperature, high-pressure water and a dynamic disturbance. Anisotropy is one of the basic properties of the rock mass. When the anisotropy of deep rock is obvious, the anisotropy shows a direct impact on the rock dynamics properties and failure modes. In this study, the dynamic experiments for deep anisotropic rock with one-dimensional and multi-dimensional pre-stress state, in order to truly reflect the characteristics of rock in high field stress and dynamic disturbance at the same time, will be conducted with impact loads by using an innovative coupled static-dynamic testing system. The influence of deep rock anisotropy on the impact strength, deformation characteristics and failure modes is studied, to reveal the fracture mechanism, the strain rate effect and energy dissipation characteristics of anisotropic rock under different coupled static and dynamic loads. Based on the impact test results, the applicability of static strength criterion for anisotropic rocks will be analyzed in the dynamic range, and the anisotropic dynamic strength criterion related to the strain rate effect will be obtained to explain the intrinsic motivation and failure mechanism of deep anisotropy rock under the coupled static and dynamic stress environment. The research results on dynamic experiment and the strength criterion for deep anisotropic rocks will provide the theoretical basis for prediction, forecasting and prevention of deep engineering disasters.

深部岩体工程处于"三高一扰动"特殊地质力学环境，岩体变形及破坏具有显著非线性和强烈动力特性，易发生分区破裂、片帮、岩爆等动力灾害。各向异性是岩体的一种基本属性，当深部岩体各向异性显现时，直接影响其动力学特性和破坏模式，为揭示岩体各向异性对深部工程灾害的影响机理，亟需对深部岩体各向异性动力学特性开展研究。本项目针对深部岩体"高应力+动力扰动"的动静组合受力特点，以岩石动静组合加载试验装置为平台，开展一维和多维动静耦合加载下各向异性岩石动力学特性试验研究，分析岩石各向异性对其冲击强度、变形特性及破坏形态的影响，揭示动静组合加载下各向异性岩石的破裂机理、应变率效应和能耗特性。基于试验结果，分析静态或动态岩石破坏准则在高应变率范围内的适用性，提出与率效应相关的各向异性动态破坏判据，阐释深部组合应力环境下各向异性岩石破坏的内在诱因和发生机制，为深部工程灾害事故的预测、预报和防治提供理论基础。

深部岩体工程处于“三高一扰动”特殊地质力学环境，岩体变形及破坏具有显著非线性和强烈动力特性，易发生分区破裂、片帮、岩爆等动力灾害。各向异性是岩石的一个重要性质，为了深入认知岩石各向异性动力学特性，本项目进行了大量室内试验，研究了动力扰动情况下各向异性岩石的变形机理和屈服破坏特性。通过岩石不同层理方向微观结构观察，阐释了岩石呈现宏观各向异性的微观机理。通过改进分离式霍普金森杆试验系统，开展了一维和多维动静耦合加载下各向异性岩石动力学特性试验研究，分析岩石各向异性对其冲击强度、变形特性及破坏形态的影响，揭示了动静组合加载下各向异性岩石的破裂机理、应变率效应和能耗特性。研究成果对于进一步分析各向异性对工程问题的影响提供了理论基础。