Evaluation And Predication Research On The Risk Of Secondary Geological Hazards Distributed In Some Railway In Southwest China

The5.12Wenchuan earthquake induced a large amount of geological hazards such as landslides and collapses, which caused large loss of life and property. With the development of the railway in western mountain region, the influence of geological hazards on the route selection, construction and running of the railway is more and more obvious. In topography, some railway in southwest region crosses plain, high mountain and valley; in geological structure, it crosses the Longmenshan fault zone, west Qinling fold and fault zone. The structure background is complicated, and the inner and outer dynamic geological effect is intense. Unfavorable geological effect is broad in distribution, diverse in type and large in scale. In all, the area that the railway crosses is complicated in engineering geology, which has such complicated and unique characteristics as "two ’new’, two ’bad’, three’large’ three ’many’", that is new tectonic movement, new unfavorable geological body, bad lithologic conditions, bad slope and rock stability, large topographic relief, many landform units, large-scale unfavorable geological body, many types, high earthquake magnitude, many active faults.The premise of the prediction of geological hazards is the evaluation of them, based on the results from the collection of literature, geoligical investigation and remote sensing image interpretation of the controlling spots along the railway, this paper summarizes the development laws, types and influencing factors of the exsited geological hazards.On the basis of the exsited disaters, the paper puts forwards the factors that influence the development of geological hazards, and with the aid of experience in the past literature and comparison method, this paper identifies the influencing factors and builds the third-grade evaluation system. And then, this paper calculates the weight of each index in the system by the use of AHP method and comparison method. Further more, this paper puts the third grade index into quantization, which correspond safe, low risk, moderate risk and high risk respectively. Furtherly, combined with model parameters, index system, index weight and fuzzy comprehensive judgment method, the paper obtains the score value of each disaster spot. With the comparison to the investigation of the spot, this paper gives the score standard corresponding to safe, low risk, moderate risk and high risk. In the end, based on the score value obtained from above, and with the powerful programming ability of SQL and C#and powerful graphical display function of GIS, this paper builds the information management system (IMS) of the railway and obtains the strip risk zoning map along the railway, which plays a guiding role in the route selection of the railway.