Preliminary Study On The Technology Of Railway Location In Landslide Risk Regions

The landslide has the largest proportion of all geological disasters in China. It has many unique features, such as widely distribution, high frequency, great harmfulness and so on. Nearly every aspect of the national economy and people’s lives has been affected by the landslide activities. Railway is one of the most frequent and serious area that is subjected to landslide hazards. For example, the line of railway is usually broken by landslide and which also causes severe personal injury and traffic accidents at the same time. Preliminary study can help us to establish many perfect principles, technical framework and operational progress on the technology of railway location in landslide risk regions. As a result, we can avoid the landslide from the source which will reduce the disaster by landslide activities along railways as much as possible. The research contents of the thesis are as follows:1. Firstly, analyzing from the climatic conditions, topography and geomorphology, seismic activity, formation lithology and combining the landslide distribution map of China the distribution laws of the landslide in China are summarized. Secondly, this paper emphatically analyzed the severity of landslide disaster that occurred in several main railways. This paper mainly analyzes the causes and prevention measures of large-scale landslide and collapse in railway. Finally, based on the disaster mechanism the disaster types and control pattern during the construction and service stage in railway are analyzed.2. Statistics and analysis of many successful stories and failures in the location design since1949are made. New contents are added to complete a complete technology system of railway location in landslide risk regions. There are many principles as follows:The first one is geological route selection. The geological conditions are very complex at complex dangerous mountain areas. The better the geological conditions, the more secure the railway. However, the worse the geological conditions, the more dangerous the railway. Geological route selection should be given enough attention, which also should occupy the first place in all the principles of the location design. Secondly, there are many line schemes to be chosen in the start and end points. But, no matter which line scheme is chosen, the principle of high line will reduce the geological hazards at the beginning. It includes four stages:(1) High line should be chosen to across the valley regions; The principle of line selection when the giant landslide blocked the river;(2) Lower elevation should be chosen to across the crossing ridge regions;(3) Landslide needs remediation when the newly built railway encountered drains in the landslide region. In the step of local selection in landslide risk regions, many large landslides or landslide groups should be avoided. It includes four stages:(1) Tunnel is chosen to escaping from landslide.(2) Bridge that spans river is chosen to escaping from landslide.(3) Bridge that spans landslide region is chosen to escaping from landslide.(4) Moving to besides is chosen to escaping from landslide. When the local line scheme was selected, there are many engineering to overpass the landslide regions. It includes four stages:(1) The railway overpass from the forward of the landslide engineering;(2) The railway overpass from the middle of the landslide engineering;(3) The railway overpass from the behind of the landslide engineering;(4) The railway overpass the landslide engineering by bridge. On the basis of above works, the technical framework and operational progress of local selection in landslide risk regions were summarized.3. This paper analyzes and compares the advantages of various GIS software. ArcGIS is chosen as the development platform, and the C#(C sharpe) language is chosen as the development tool to write the program of rapid discriminant method of slope stability in landslide risk regions. Firstly, divided the topographic map which has a certain accuracy of gird into slope units by the hydrological analysis tools of ArcGIS and export the data of the grid point coordinates, slope and aspect to the spreadsheet of Excel. Secondly, calculate the slope and aspect of every slope unit. Search of the most dangerous slip surface by Monte-Carto random method. Combined with the classical three-dimensional-mechanical model the stabilizing force and pushing force of the sliding surface are found. Then, the safety factors are got and the map of hazard zoning of slope is made. Finally, use the program of rapid discriminant method of slope stability in landslide risk regions to approximate alignment in space.According to the research, the following results are obtained:(1) The types of disaster by landslide activities along railway are analyzed and the model of engineering control is summarized:(2) New contents are added to perfect the principles, technical framework and operational progress about railway location in landslide risk regions.(3) The program of rapid discriminant method of slope stability in landslide risk regions are completed;(4) The slop map that easily affected the newly built railway, the map of hazard zoning of slope and the map of hazard zoning of collapse are obtained.