Geologic Hazards And Development Of Highway From Shiyan To Tianshui Throughout Shaanxi Provience

The highway from Shiyan to Tianshui position at ShanNanQinBa Mountains in Shaanxi.The Study area have complex geological structure,significant difference of rock and soil and also position at the frequent rain subtropical monsoon climate zone.in recent years, the rapid development of the national economy and Strengthening of human engineering activities Lead to geological disasters are well developed There are wide variety of geological disasters in Qinba Mountain,of which the largest were landslide and debris flow hazards,at the same time,geological disasters caused to the residents along the highway and its a great threat.to the people who live along the highway.This article relies on the national highway network under construction Shiyan-Tianshui contact line G7011, about the ankang-shiyan and the hanzhong-gansu, to have a study about the characteristics of disaster, such as the landslide, the collapse and the debris flow along the highway.The paper analyzes the environmental conditions in Qin-ba mountains area along the Shiyan to Tianshui expressway, such as the terrain and landforms, Weather and Hydrology Condition, the formation lithology,the geologic(al) structure and so on.The paper also analyses systematically the distribution and the developing characteristics of the geological disasters including the landslide, the collapse and the debris flow. The distribution has the characteristics of relative concentration in both space and time. And its concrete performance is as follows. Firstly, disasters mostly strike in the rainy season. Secondly,the distribution of the surface is mainly strip-shaped.Landslide is the most prominent and harmful geohazard type in the study area. The paper drew three conclusions on the base of the statistical analysis of the survey data. Pint-sized accumulated layer landslide is major and widely distributed in the region. The paper summarized slope failure modes caused by landslides along the highway. And it studies all typical examples of the modes. The paper analyses detailedly the internal and external factors causing landslides.Debris flow and collapse are also the main types of geological disasters in the study area. The paper elaborates their development and distribution characteristics. The main type of debris flows is the valley-type water stone debris flow which is very destructive. Nearly all the collapses are rock collapse mainly happened in the steep cliff.