降雨及地震作用对岷江上游干暖河谷区大型冰川(水)堆积物复活变形的贡献度研究

岷江上游分布的众多大型冰川(水)堆积体斜坡，地处干暖少雨的河谷区和强震地带，目前已发生明显复活变形形成滑坡。前期初步研究认为由降雨和地震作用引起，且降雨影响更大，但对二者作用的贡献度还缺乏系统试验支撑和有效对比，且对地震烈度影响的评价还与实际偏差较大，对堆积体细观结构特征变化和宏观特性反映的认识还不深入。为此，本项目拟首先对该类堆积体的基本细观结构及特性进行研究，然后结合典型降雨模式及地震作用，对其细观结构特征演变及力学和变形特性反应进行对比试验，确定降雨和地震各自对斜坡稳定性的作用程度和变化规律，以及二者关系与影响可能的临界转换点。同时，研究切合实际的堆积体动强度参数与地震加速度变化的关系，提出地震加速度和动强度建议值。最后，结合典型实例，采用离心机/振动台和三维数值模拟分析方法，验证分析降雨和地震对斜坡复活变形的贡献度。成果将为深入认识该类堆积体细观结构与特性及稳定性分析方法等提支撑。

In the dry-warm and less rainfall valley and strong earthquake zone of the upper Minjiang River, there are many large-scale glacial (glaciofluvial) deposit slopes that have occurred obvious revived deformation, forming a certain type of landslide that is called "revived landslides". The preliminary research results thought that these phenomena were caused by rainfall and earthquake action, and the rainfall influence was greater than earthquake. But the respective contribution of rainfall and earthquake action is lack of effective contrast and supports of the system testing, and evaluation results of the impact of earthquake intensity gained from current standard deviated quiet large from actual value, also with the actual mesoscopic structure change and macroscopic features reflect of deposit is not well understood. So, this project firstly studies the basic mesoscopic structure and the characteristics of the deposit, and then combined with the typical rainfall patterns and earthquake action, through the contrast test about the mesoscopic structure evolution and the mechanics and deformation response, determines the respective extent of rainfall and earthquake action on the stability of slopes and their change law, as well as the two relations and possible critical transition point of impact. Meanwhile, the research tries to ascertain the corresponding relationship between the dynamic strength parameter and the seismic acceleration of the deposit, and suggests proper earthquake acceleration and dynamic strength values. Finally, combined with typical examples, the research, using the large-scale centrifuge testing or vibrating table and three-dimensional numerical simulation analysis method, will validates the rainfall and earthquake action to the contribution of the revived deformation. The result will provide strong supports for further understanding the mesoscopic structure, the properties, and the stability analysis method of the deposits, and so on.