基于小变形与大位移分析的滑坡全过程及机理研究

The nature of the landslide disaster is the failure of rock. The traditional method of slope stability analysis is based on the homogeneous, continuous mechanics theoretical framework, which is difficult to study the failure process of landslide disaster. The project is based on the concepts of "the accumulation of micro-fractures and their progressive development is the source of landslide disaster" and "brittle fracture is a small deformation" and "the non-linear deformation is because of rock heterogeneity". This project proposed a new idea to study the landslide disaster which is based on the small deformation and large displacement concept of rock failure. By implementing the rock failure process analysis method (RFPA) coupled with the displacement deformation analysis (DDA) method, this project would propose a numerical method to simulate the whole process of landslide disaster, including the initiation, propagation and coalescence process of cracks and the large displacement of rock blocks after failure. The systematical study the mechanism of high steep rock slope failure, it will further discusses the stress distribution, redistribution and the damage evolution to explain the mechanism of rock slope failure. This project will also propose the criteria to estimate the degree of slope failure and a design method to guide the construction of slope. This project not only has a theoretical value for the development of rock mechanics, but also important for improving the level of structural design and safety assessment of the rock engineering in our country.

滑坡灾害的本质是岩石的破坏问题。传统的边坡稳定性分析方法多数是基于均匀、连续介质力学的理论框架，难以对岩石的破裂过程与岩体工程灾害进行有效的分析。本项目基于“岩质边坡细观岩体微破裂聚积和演化渐进发展是边坡宏观失稳前兆”的学术思想，以及“脆性破裂孕育在小变形之中”和“岩石的非线性源自岩石的非均匀性”两个基本认识，提出基于小变形和大位移原理的滑坡灾害全过程分析方法研究新思路。通过实现岩石破裂过程分析RFPA方法与非连续位移分析（DDA）方法程序上的耦合，从而实现岩体从变形、破裂到岩块运动的全过程的模拟。利用离心机方法验证模型的可靠性。通过系统地研究高陡岩质边坡破坏过程中微破裂的萌生、发育、扩展、相互作用和贯通的机理，探索岩质边坡渐进破坏过程中应力场和损伤累积演化基本规律，提出高陡岩质边坡稳定性评价标准与灾害预测设计方法，研究成果具有理有理论价值和实际的工程意义。

滑坡灾害的本质是岩石的破坏问题，本项目基于“岩质边坡细观岩体微破裂聚积和演化渐进发展是边坡宏观失稳前兆”的学术思想，以及“脆性破裂孕育在小变形之中”和“岩石的非线性源自岩石的非均匀性”两个基本认识，提出基于小变形和大位移原理的滑坡灾害全过程分析方法研究新思路，开发了用于岩质边坡从连续到非连续全过程分析的非连续位移分析（DDA）方法。同时，提出的岩体缺陷模型统一建模方法，开发了CT-RFPA软件，实现了基于CT扫描数据生成数值试样模拟，将损伤过程渗透模型嵌入RFPA中，实现了基于PC机与跨平台的数值模型的并行求解等。在DDD方法中，通过推导统一的总体平衡方程，以联合求解连续问题和非连续问题，实现了利用统一的计算模型同时模拟连续的子区域和非连续的结构面的力学行为；通过构建特定的破裂序列，沟通连续介质与非连续介质方法，实现了岩石材料从连续介质到非连续介质的自动转化；通过建立统一的分析框架，完整概括岩石小变形阶段的破碎过程与大位移阶段的运动与接触过程，实现了岩石材料破坏失稳的全过程模拟。DDD方法的模拟结果与理论分析、前人的研究成果和试验数据能够很好地相互印证，已经表现出来了明显优于传统数值方法的独特优势。