降雨条件下岩质边坡变形破坏过程及其预测模型研究

Abstract: China is a landslide hazard-prone country. In the case of global increment of extreme weather, environmental degradation, landslide disasters become more frequent. With the deepening of China's modernization process, the development of the West, South-to-North water diversion, West-to-East gas supply, "five vertical and seven horizontal" road construction, "four vertical and four horizontal" high-speed railway construction and more other human engineering activities, the landslide hazard becomes more serious. Under complex environmental conditions, especially rainfall, the ancient landslide is easy to resurrect, and the poor slope may cause a newborn landslide easily. In the current project, a typical rock slope of the Three Gorges reservoir area is selected. The multi-scale experimental study will be carried out for the microscopic structure of joint and its macroscopic physical properties. A macro constitutive model of rock with the consideration of microstructure and rainfall effect will be developed with the model for the structure of surface of rock. An extended finite element program is coded to analyze the crack expansion or structural surface sliding shear failure process subjected to the rainfall. Both the proposed model and the program will be verified by the comparison between simulation results and typical rock slope site monitoring data and also physical modeling results. The prediction model can be used in the practical engineering to investigate the mechanism of failure evolution process of rock slope under rainfall condition.

我国是滑坡灾害多发国家。在全球极端气候增加、环境不断恶化情况下，滑坡灾害更加频繁。随着我国现代化进程的深入，西部开发、南水北调、西气东送、"五纵七横"的公路主骨架建设、"四纵四横"的高铁建设等人类工程活动的加强，滑坡灾害更加严重。在复杂环境条件下，特别是在降雨作用下，古滑坡极易复活，不利的边坡极易产生新生型滑坡。本项目选择三峡库区典型岩质边坡，对其岩块和结构面进行微、细观结构和宏观物理性能的多尺度的试验研究；建立考虑降雨作用下基于微、细观结构的岩石宏观本构关系和结构面的宏观本构模型；编制降雨作用下裂缝开裂与扩展或结构面滑动与剪切破坏过程的扩展有限元程序；通过数值模拟结果与典型岩质边坡的现场监测资料和地质力学模型试验结果的比较分析，验证本课题建立考虑降雨作用下岩体（岩块和结构面）宏观本构模型和数值计算程序的合理性。将计算模型应用于实际工程，研究降雨作用下岩质边坡破坏演化过程及其机理。

在复杂环境条件下，特别是降雨作用下，极易引起岩质边坡的裂缝开裂，进而引发滑坡。本项目选择典型岩质边坡，对其岩块和结构面进行微、细观结构和宏观物理性能进行研究，建立考虑降雨作用下基于微、细观结构的岩石宏观本构模型，编制了降雨作用下裂缝开裂与扩展过程的扩展有限元程序，通过数值模拟研究了岩质边坡中裂缝开裂过程及水压力与应力场的耦合作用，验证了宏观本构模型和数值计算程序的合理性。并且依据项目需求，进行了地质力学磁力模型试验的理论研究和设备开发，研制了可应用于模型试验的磁场发生装置，并以典型岩质边坡为例进行了模型试验研究，通过与数值模拟结果的对比，验证了地质力学磁力模型试验结果的有效性，反映了地质力学磁力模型试验的工程应用价值,为复杂环境下岩质边坡的安全稳定性的试验研究提供新的试验方法。