Study On Characteristics And Effects Of The Slope Body Structures Of Loess Slope

Loess slope is one of the typical geomorphologic landscapes in northwest of China. The special characteristics of loess slope led to a series of engineering and geological disasters in the process of gas pipeline project, high voltage transmission line engineering and so on. The loess slope with complex properties severely restricts the urban construction and the major engineering construction. For this case, this thesis focuses on the research of the effects of loess slope geological disasters from the perspective of the slope body structure characteristics with the area of Gansu province, and adopts the way that a combination of field investigation and indoor research literatures. Then putting forward to the conception of the loess slope body structure, the loess slope is classified by loess slope body structure. Finally, slope structure effect of loess slope is discussed by the numerical computing. This work has important theoretical and practical significance to the survey, design, prevention and evaluation of the loess slope geological disasters in western region.The main results in this thesis as follows.(1) Putting forward to the conception of the loess slope body structure and summing up the slope body structure characteristics of the loess slope. The loess slope body structure is the internal combination relationships between the loess slope lithology characteristics, interface characteristics and slope free surface conditions, The lithology characteristic of loess slope is the essential difference between the loess slope and other slope types, and it is the material basis of constitution; the interface characteristic of loess slope is very important to the evolution of the loess slope; the condition of free surface characteristic of loess slope is external manifestation of the loess slope, it is a prerequisite condition of all kinds of disasters.(2) The loess slope is classified by the loess slope body structure and summed up the essential characteristics of the typical types of loess slope. Considering the important influence factors of the loess slope body structure, the loess slope is devided into three kinds based on the bedrock orientation, or the loess slope is classified into thirty-six kinds based on interface form and the relationship between the interface and the free surface, and found that different bedrock orientation of loess slopes has different slope body structure characteristics.(3) The loess slope structure has different effects on the deformation evolution mechanism and stability of loess slope, the effects of the lithology is mainly manifested in the obvious "double effects" of the loess layer structure and lithology combination, the effect of interface plays a key role to deformation evolution process and failure mode of the loess slope, the conditions of free surface show the internal stress distribution and stress size of the loess slope, and directly affect the stability and its possible deformation and failure mode of loess slope.