Study On The Distribution Characteristics Of Geological Hazards In The Qinghai-Tibet Railway

Qinghai-Tibet Railway is located in the hinterland of the Qinghai-Tibet Plateau, the geological structure is strong, earthquakes are frequent, natural conditions are harsh, along with many types of geological hazardas. The research object of this thesis is the main geological hazards in the Qinghai-Tibet Railway KO-K360 section, K1100-1580 section, it made overlay analysis with the engineering geological conditions of the corresponding geological hazards, rainfall characteristics, climate and temperature difference between day and night and geological disasters distribution diagram,concluded the distribution law of the main geological hazards (the roadbed settlement and the topsoil slip), partioned the severity of the geological hazards along the line using fuzzy comprehensive evaluation method, put forward suggestions on preventing geological hazards according to engineering geological conditions and adverse geological characteristics along the Qinghai-Tibet railway.The main contents of this paper are as follows:1、Summarized the Qinghai-Tibet Railway K0-K360 section, K1100-1580 section of the engineering geological conditions, climate, rainfall and temperature difference between day and night, obtained the relationship between the main geological hazards (settlement of the embankment and topsoil slip) distribution features and geological environmental conditions The main results are as follows:1) The formation of the roadbed settlement along the intersections of active fault zone, showing zonal distribution.along the parallel region of the Qinghai-Tibet Railway between the active fault zone, showing concentrate distribution.along the active fault zone;2) The subgrade settlements are mainly developed in the weak rock area and the loose accumulation area;3)The settlements of the roadbed are mainly developed in the relatively flat terrain of the basin;4) The control effect of Permafrost on the development of subgrade settlement as follows:high temperature region of permafrost is easy to produce subgrade settlement, high content of frozen soil area is easy to produce subgrade settlement, the intensive development of the geological structural cracks promotes the development of the subgrade settlement in permafrost regions., the distribution of subgrade settlement along the high subgrade section;5) The topsoil slips are showing concentrate distribution.along the active fault zone;6) Soft rock zone and loose accumulation area are the mainly area where the topsoil slips developed;7) The steep terrain offered dynamic conditions for the topsoil slips developing;8)The climatic conditions and the earthquakes are the induced function to the topsoil slips developing.2、Combined with experts’opinions and the development law of geological disasters in the study area, puting forward 10 evaluation factors to establish the index system on the comprehensive zonation of the geological disaster severity, which including the density of the geological hazards,the degree of risk of the geological hazard points,24 hours rainfall along the railway line, the terrain conditions, the properties and structure type of rock and soil, the degree of human economic activities, the vegetation coverage rate, the density of folds and faults, the development history of geological disasters, the earthquake intensity.3、Taking 500m range on both sides of the railway line and 20km along the railway line as an analysis unit, it made comprehensive regionalization of geological hazards using comprehensive fuzzy evaluation method in the study area.4、According to the distribution law of geological hazards in the study area to put forward the principles and measures for the prevention and control of various types of geological hazards, and put forward some suggestions for the prevention and control of the geological hazard points.