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Study On The Risks Of Moraine Landsliede Blocking River Along Sichuan-Tibet Transportation Corridor And Disaster Reduction Strategies In Route Engineering

Posted on:2016-01-22Degree:MasterType:Thesis
Country:ChinaCandidate:C Y LiangFull Text:PDF
GTID:2180330461470193Subject:Disaster Prevention
Abstract/Summary:PDF Full Text Request
The geological condition and natural environment along Sichuan-Tibet transportation corridor is special and complex. This provide a full range of foundation for the development of geological disasters. Geological disasters along the corridor are so active, which have entire types of disasters, big distribution density and high frequency more over, as well as huge scale of activity, high extent of hazard and wide range of influence at home and abroad. Particularly, the "Sanjiang" valley which are located among the Hengduan mountains and Palongzangbu valley which is located north of the great bend of Yaluzangbu river, are the high incidence of mountain hazards (especially the landslide blocking river disasters) area. Deep-incised vallies, high mountains and steep slopes, active new structural movement, frequent earthquakes, deep loose Quaternary glacial deposits, development of maritime glacier, numerous glacial lakes and abundant regional rainfall provide a favorable conditions for the development of the landslide blocking river disasters. Under such adverse geological conditions, the landslide blocking river disasters will be the unavoidable problems in the construction of the Sichuan-Tibet railway with no doubt. Therefore, in order to achieve effective disaster prevention and mitigation, and minimize the impact of landslide blocking river disasters on the Sichuan-Tibet railway construction, it is necessary to study the issue of landslide blocking river disasters.The occurrence of geological disasters, especially the landslides disasters, depends on the particular geological background and the natural environment. Meanwhile, the study of the cause and the mechanism of geological hazards is the base of disasters management. Hence, the author studied the types, formation conditions, failure modes and disaster chain of landslide dammed lakes. And then, the author comprehensively analyzed disaster pregnant environment (including the geological structure, topography, meteorology and hydrology etc.) and distribution patterns of landslide blocking river hazards along the Sichuan-Tibet corridor. Figuring out these fundamental questions will provide a scientific basis for the landslide blocking river hazard mitigation countermeasures.The accumulation patterns of the landslide debris which slide into the valley along the sliding face after the failure directly determines the storage capacity and the depth of the landslide dammed lakes which determines the inundated area of the landslide dammed lakes and the maximum peak height that the outburst flood can reach. Thereby, it determines the location and the minimum altitude of the route. Based on this understanding, this paper perform a numerical simulation about the accumulation patterns of loose deposit like moraine. Using the two-dimensional particle flow code (PFC2D) which is based on discrete element method, we analysis the impact of single factor like export of cut height, volume, contour of valley (including the valley slope and the valley width) on the accumulation patterns of loose deposit in the valley. Then, we extract the main factor, and run another series of calculations to obtain the minimum height of the landslide dam under different combinations of the main factors. In addition, in order to verify the applicability of the particle flow code in the simulation of movement of the loose deposit, we perform another simulation about a typical case of landslide blocking river-102 landslide. The result turned out to be good.In the end, according to the earlier study about the landslide blocking river disasters along the Sichuan-Tibet corridor, the author put forward corresponding line control strategies to guarantee the Sichuan-Tibet railway pass the severe landslide blocking river disaster zone.
Keywords/Search Tags:Sichuan-Tibet Transportation Corridor, Landslide-dammed Lakes, Moraine, Discrete Element Method(DEM), PFC2D, Accumulation Patterns, Route Strategy
PDF Full Text Request
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