层状各向异性岩体的工程地质力学模型及渐进破坏特征研究

The laminated anisotropic rock masses, represented by sedimentary and para-metamorphic rock, are very common seen in the projects. Due to the complex mechanical behaviors of such rock masses, there are short of corresponding treatment measures. Casualties, machine damages and project delay always occur during construction in such rock masses. The engineering geomechanical models generalization and the corresponding quantitative structure parameters, as well as the quantitative expression of the macro and micro characteristics during the progressive failure are the key problems to know the behavior of the laminated anisotropic rock masses, which have not been studied enough and need further research urgently. Based on the field investigation and engineering geological data of abundant laminated anisotropic rock mass projects, analyze diagenetic environment, reformation process and mechanical behavior. Generalize the engineering geomechanical models and the corresponding quantitative structure parameters. Based on special rock lab tests and real-time observation with CT on several typical laminated rock samples, analyze the process of strength parameters and crack evolution during progressive failure, and propose a plastic –strain dependent strength model. Conduct case study based on typical laminated anisotropic rock mass projects. Generalize their engineering geomechanical models, obtain the relations between strength parameters and structure parameters on the basis of refined numerical simulation. Make application of the proposed strength model in the similar projects, and provide scientific basis for treatment measures.

以沉积岩和副变质岩为代表的层状各向异性岩体在各类工程中极为常见，其力学行为十分复杂，工程中缺乏针对性防护措施，常造成人员伤亡、机器损毁、工期延后等生命财产损失。层状各向异性岩体的工程地质力学模型概化及其结构参数表达和渐进破坏宏细观过程的定量刻画是认识该类岩体致灾机理的关键科学问题，前人相关研究十分欠缺，亟需深入。本项目拟基于大量层状各向异性岩体工程的原位调查及工程地质资料，分析成岩建造环境、后期改造过程及变形破坏力学行为，建立其工程地质力学模型及结构定量化表达。选取典型层状各向异性岩体试样，通过独特的岩石力学试验、CT实时观测技术等手段分析其渐进破坏过程中强度参数变化规律及裂纹演化机理，实现强度参数的定量刻画。以典型层状各向异性岩体工程为研究对象，概化其工程地质力学模型，进行精细化数值模拟，建立其结构参数与强度参数的关系。将提出的强度模型进行推广应用，为类似工程实践的防灾控灾提供科学依据。

以沉积岩和副变质岩为代表的层状各向异性岩体在各类工程中极为常见，其力学行为十分复杂，工程中缺乏针对性防护措施，常造成人员伤亡、机器损毁、工期延后等生命财产损失。层状各向异性岩体的工程地质力学模型概化及其结构参数表达和渐进破坏宏细观过程的定量刻画是认识该类岩体致灾机理的关键科学问题，前人相关研究十分欠缺，亟需深入。针对于此，本项目以典型层状各向异性岩体工程为研究对象，概化其工程地质力学模型，建立了一种基于BQ的各向异性岩体质量分级系统——A-BQ,该系统可用来评估岩体的各向异性程度，同时还可以对各向异性岩体的质量进行评估分级；其次，开展了典型层状各向异性岩体试样的室内试验，通过独特的岩石力学试验、CT实时观测技术等手段分析其渐进破坏过程中强度参数变化规律及裂纹演化机理，建立了基于塑性应变累积的岩体渐进破坏强度准则——CWFS-TL模型，实现强度参数的定量刻画；在此基础上，利用FLAC3D开展精细化数值模拟，研究了非均质材料破坏过程中围压对应力和破裂过程的影响，建立其结构参数与强度参数的关系；针对含非贯通结构面的各向异性岩体，提出了考虑非线性渐进破坏过程的非贯通结构面岩体抗剪强度新准则。基于以上研究，发表学术论文10篇，其中SCI收录9篇，授权专利12项，其中中国发明专利7项、实用新型专利3项，美国发明专利1项、澳大利亚革新专利1项，依托项目取得的成果作为主要创新点于2020年获第11届中国岩石力学与工程学会“自然科学”一等奖。本研究为层状各向异性岩体工程建设运行维护过程中的防灾控灾提供科学依据。