Geological Disaster Risk Assessment Of The PAIMO Highway Engineering In The Tibet’s Nyingchi City

The study area is located in the border zone of Medog county and Milin County of the Linzhi city, which is one of the least developed areas in traffic of china.The geological environment condition of this area is very complex, tectonic fracture development.At the same time the design highway must arcoss different climatic zones、different topography and complex formation conditions,all these factors lead the area’s geological disaster develSopt jolly.So, it is extremely difficult to construction the Medog highway and use it well for a long-term.So even now,there are little success although the construction action of the Medog highway were never stopping. To built a highway that can be used for a long time, it is necessary to make an accurate assessment of the risk for the highway geological disasters,only in this way, can we pre vention the geological hazards problems effectively that occured during the highway’s construct and using process. And in this paper,the research is expanded in this background. The construction of the Medog highwayis of great significance to the region,such as response to a national development of western history major decisions, accelerate local economic development, development of local tourism resources, improve production and living standards of local people has et.The research of this paper is based on the ascertain natural geological conditions in the study area(natural condition, weather, hydrology, etc.)and analyze the engineering geological conditions along the highway(including the landform, stratum lithology, hydrogeological conditions and the influencing factors of highway construction);at the same time, summarized the current situation of the development of geological disasters in the study area, development type and characteristics, influence factors, etc. through the field investigation and analysis, and combined with remote sensing technology as well; And then, on the basis of above research, to evaluate road risk assessment of geological hazard and highway vulnerability assessment;finally comprehensive the above results, evaluate the highway geological disaster risk, concluded the PAIMO Highway geological disaster risk distribution, provide the basis for the construction of highway operation.In this paper, the research shows that the elevation difference along the proposed highway is big, valley are very deep,at the same time, the geological disasters are well-developed in the region because of the regional tectonics, weathering and rainfall factors.Strong regional neotectonic movement in the study area, develops the regional fracture structure, this article interpretation interpretation 14 faultages in total,each linear feature significant fault zone,regional geological data show that the faultage act strong.The geological disasters types in the study area are complete,but are mainly composed of debris flow, landslide second, the collapse at least, they are given priority to with small and medium-sized, their distribution presents a centralized and zonal characteristic, More disasters distributed near the main riverway、near the fault zone and in the bigger amount of rainfall area,often frequent in the rainy season(from may to October). The Geological disasters often occured in a small scale, but their activity are frequent、active and dangerous.The evaluation results show: The most geological disaster segment of the PAIMO highway are about 18 km, accounting for 23.38% of the total length of the road; moderate risk the total mileage are about 40 km, accounting for 51.95% of the total length of the road; the total mileage low danger about 19 km, accounting for 24.68% of the total length of the highway. Overall, geological hazard along the PAIMO highway are moderate.The road height vulnerability zone mainly in the later half of the highway where the bridge concentrate relatively, accounting for 27.63% the proportion of road length; moderate vulnerability area the tunnel section and good geological conditions of the construction of a bridge institution sector, accounting for 37.21% the proportion of road length; low vulnerability zone across the board have the right amount of distribution, mainly road construction in general, or geological conditions are better segment, accounting for 35.16% the proportion of road length. O vera ll, send ink road because of poor roads, high cost, poor engineering geological conditions and other factors, the overall vulnerability are achieve medium to high level.Synthetical Evaluation: high risk area are for a total of 27 km, 33.90% of the total mileage,these areas are suitable to build highway in taking effective preventive measures for existing and potential geological disasters. Medium risk area total of 26.64 km, 33.45% of the total mileage, these areas are suitable to build highway in taking effective preventive measures for existing and potential geological disasters. The low risk area are about 26 km, accounting for 32.65% of the total mileage, where are suitable for the highway construction.O n the whole, this project is suitable for construction when the work on the prevention and control for the high risk area had well done.