Study On Along Highway Cutting Slope Structure Of G318 State Rode In Tibet

Because of the complicated geological conditions and strong tectonic movements in Tibet, there are various slope forms in the region as well as slope stability conditions, that is one of the typical landscapes in Tibet. During the western development and infrastructure construction in Tibetan areas, there exist mutual constraint and influence between these major projects and the slope, inducing a series of engineering diseases and secondary disasters and seriously affecting infrastructure and construction of major projects. In this paper, the Tibet G318 region slope geological conditions and environmental characteristics were In-depth studied. This paper summarized the types of slope structure through in-depth investigation and analysis, combined with domestic and foreign literatures, also proposed edge slope structure classification in the G318 area, combined with The unique geological environment in the study area, and expounded all kinds of the main characteristics of the slope body structure and its corresponding buckling failure mode. They have important theoretical and practical significance to the reasonable evaluation of Tibet G318 region slope geological disasters and reasonable design of control engineering measures.The main research contents and results are as follows:(1) Expound the geological environmental conditions of research area, in detail base on detailed investigation on the geological conditions in the study area. Strong tectonic movement is a characteristic in this study area. This lays the foundation for the research on the structure of the slope.(2) The structure type of the slope of the national highway G318 in Tibet is closely related to the geological environment of Tibet area. For example, the Tibet region of the terrain, the formation of the terrain, are related to the Qinghai Tibet Plateau by the tectonic movement and the movement of glaciers (see chapter second). The lithology of the slope of the G318 State Road in Tibet area includes magmatic rock, metamorphic rock and sedimentary rock, mainly the previous two (see the third chapter), which is closely related to the geological environment of the study area. Because of a combination of different lithology, airport surface and rock and soil physical and mechanical properties of slope play different failure. Therefore, the above factors as the classification of slope structure of main basis (see Chapter 3).(3) Collapses and landslides are the most vulnerable types of disasters along the G318 national highway. The number of geological disasters of collapse in study section is 162, scale to small and medium-sized collapse, accounted for 75%, human activities is the mainly controlling factors, loose rock accounted for more than 50% material consisting, stability condition is basically stable, less stable, and the trend is less stable and unstable. The study area develop 39 landslide geological disasters, in which small and medium-sized landslide accounted for more than 75%, the thickness of landslide body mostly less than 20m, mainly the traction type landslide caused by human activities, material composition is mainly loose soil and soil rock mixture. The bedrock landslide only eight, accounting for approximately 20% of the total amount. The stability condition is similar to the collapse, the current situation is basically stable and unstable, and the development trend is understable or unstable.(4) The collapse and landslide in the study area shows a certain regularity. The development of collapse and landslide shows obvious features which influenced by the human activities. The collapse and landslide affect the national highway G317 ranging from tens of meters to hundreds of meters, a few effect even reach to several kilometers (in chapter 4).(5) The slope structure in Tibet highway G318 can be divided into layered slope structure, block slope structure, fracture slope body structure, joint control slope with loose structure, slope body structure, bond structure and the type rock which "under" on soil slope structure. THE type of layered slope body structure, joint control slope with loose structure, slope body structure and bond type and type rock "under" on soil slope structure is more common. And collapse mainly occurs in block slope structure, fracture slope structure, cementation type slope structure and rock "under" on soil slope structure. Landslide mainly occurs in bedded slope body structure and landslide, loose and rock "under" on soil slope structure (in chapter 3 and 4).(6) Through a numerical simulation of typical slope structure in the study area, we can get the slope failure mode and the type of slope structure is consistent. To some degree, it proves that the slope structure constructed in this paper and its corresponding instability failure mode are correct.