Research On Risk Assessment Of Geological Hazards In The Highway Of Mountain Area

High and cold mountain area, characterized by its complicated mountain area condition in geography, is abundant with geological hazards such as collapse, landslide , debris flow and frozen soil. With the development of engineering in this area, the deteriorate rate and the frequency of the geological hazards tend to accelerate. Therefore, how to evaluate these geological hazards and geological environment quality of the high and cold mountain area is important to prove scientific basis to the engineering. In this paper, reasonable discussions have been dug into this research domain.In this article, we take the geological hazards along the highway from No.219 national road to Zanda in Ngari region of Tibet as the research objects. On the basis of out-site inspection and detailed analysis of geology data, the author expatiates the regional environmental geology and summaries the geological disaster type, scale and developing and distribution characterization in the representative area. Constructed the suitable categorization criterion of actual geologic environment in high and cold mountain area for the predictable evaluation of single geological hazard, determined the weights of evaluation factor with the analytic hierarchy process method. Hazard assessment of collapse, excavated highway slope and debris flow respectively made with fuzzy synthetic evaluation. Also the paper evaluated the dangerous degree of landslide and frozen soil area with integrated index method.Lastly, the author constructed the basic index system for comprehensive risk evaluation of geological hazards in high and cold mountain area, definited the criterion of the evaluation factor and given the criterion value of the corresponding factor. This paper respectively evaluated the geological environment quality of highway with the grey clustering method and AHP-based two-level fuzzy synthetic evaluation. The results of quantitative evaluation are satisfied with the qualitative analysis. At the same time the article combined macro qualitative analysis to divide the geological hazards along the highway. In general, the geological environment quality of the studied field is good. The quantitative evaluation method is a new attempt to risk comprehensive assessment of geological hazards for construction land and gets good effect. The study results are accorded with the real disastrous conditions and have strong practicability. It can become the reference to the risk assessment of geological hazards for construction land in the future.