复杂应力条件下深部节理岩体渗透破坏机理及试验研究

Being in the conditions of high stress and seepage pressure, the mechanical behaviors of deep jointed rock mass shows a quite difference from that of shallow rock mass. The mechanical model and hydro-mechanical coupling mechanism under complex stress conditions are both studied by employing such methods as model test, theory research and numerical analysis. Triaxial compression test and unloading test are carried out to study the failure modes and mechanical behaviors of jointed rock mass under high confining pressure. The jointed rock mass strength calculation criterion under confining pressure unloading condition will be given. The effect of different stress path to deformation characteristics, mechanical parameters, failure modes and mechanism in the conditions of high seepage pressure is studied. Using micromechanics theory,the seepage-stress coupling mode of deep jointed rock masses subjected to the action of seepage-stress will be studied. The research on the nonlinear damage deformation, as well as the evolution law of coefficient of permeability in the process of loading and unloading are summarized systematically. The strain hardening-softening constitutive model considered dilate effect which is applied to the brittle rock under high stress condition is established. A safety evaluation named by dilate safety factor of wall rock of underground rock project is derived to make the security disturbance district of wall rock excavation from the perspective of theoretical and experimental. The research has important guiding significance to failure mechanism and stability analysis of the deep-buried caverns and high slope in the conditions of high stress, and seepage pressure.

深部节理岩体所处的高地应力、高渗透水压力的特殊环境，使深部节理岩体的力学响应明显有别于浅部岩体的力学行为。本项目应用实验、理论和数值模拟相结合的手段，系统的研究复杂应力条件下深部节理岩体的渗透破坏机理。通过高围压下的三轴加卸荷试验，对含节理岩石试件的力学特性、强度特征和宏观破坏模式进行研究，建立卸荷条件下节理岩体强度准则；研究高渗压作用下，应力路径（加卸载方式、速率）对含节理岩石在变形特征、力学参数、破坏形态、强度特征及破坏演化机制等方面的影响，推导出渗透系数随应力路径变化的数学表达。基于颗粒流理论从细观角度研究深部节理岩体渗透破坏的耦合作用模式以及在加卸载过程中非线性损伤变形和渗透系数演化规律，建立适用于高应力、高渗压条件下节理岩体考虑扩容效应的本构模型以及考虑扩容效应的安全评价指标。研究成果对高地应力和高渗透水压力下的深埋洞室围岩、高边坡等的稳定性及破坏机理研究有重要的指导意义。

深部节理岩体所处的高地应力、高渗透水压力的特殊环境，使深部节理岩体的力学响应明显有别于浅部岩体的力学行为。本项目应用实验、理论和数值模拟相结合的手段，系统的研究复杂应力条件下深部节理岩体的渗透破坏机理。通过高围压下的三轴加卸荷试验，对含节理岩石试件的力学特性、强度特征和宏观破坏模式进行研究，建立了卸荷条件下节理岩体强度准则；通过剪切渗流试验，研究了渗流作用下应力路径对含节理岩石在变形特征、力学参数、破坏形态、强度特征及破坏演化机制等方面的影响，推导出渗透系数随应力路径变化的数学表达。研究深部节理岩体渗透破坏的耦合作用模式以及在加卸载过程中非线性损伤变形和渗透系数演化规律，建立适用于复杂条件下节理岩体考虑扩容效应的本构模型以及考虑扩容效应的安全评价指标。研究成果对高地应力和高渗透水压力下的深埋洞室围岩、高边坡等的稳定性及破坏机理研究有重要的指导意义。