Risk Assessment Of The Ground Fissures Disaster Among Datong-Xi'an High-speed Rail Segment In Dali County

Ground fissure is a kind of ground liner geological disaster,which is different from collapse,landslides and debris flows is ephemeral.it has the characteristics of long-term and gradual.The activity and development of the ground fissures will directly threaten and even destroy the high-speed railway when it works through the ground fissures or within the influential scope.The risk assessment of the ground fissure disaster is to make a qualitative and quantitative assessment of the damage and the consequences of the damage before the disaster occurs.This paper is based on the China Geological Survey's geological survey Level 2 Project "Geological Disaster Investigation of Ground Fissures in Weinan Area of Guanzhong Basin".According to the basis of existing geological data and combining with field dynamic investigation of Dali county ground fissures,we analyzed the distribution regularity,developmental characteristics and its influencing factors of the ground fissures along Da tong-xi'an high speed rail.Considering the geological environmental conditions,the growth situation,predisposing factors of ground fissure and high-speed rail's disaster bearing capacity,we have established an evaluation index system of ground fissure disaster risk,which includes physiognomy type,the distance from the fracture,ground fissure's development degree,ground fissure's development scale,ground subsidence,collapsibility loess,annual average rainfall and human engineering activities,the distance between high speed rail and ground fissure,the intersection angle of high speed rail and ground fissure,the crossing mode of high-speed rail and high-speed rail project location and other factors.A risk assessment model is established for the comprehensive evaluation of ground fissure disaster along the high-speed railway.Using the analytic hierarchy process mode(AHP)to determine the weight coefficient of each index then use fuzzy comprehensive model and the index weighting model for evaluation of risk degree,made risk distribution map with GIS software,and the risk level and distribution of ground fissure is defined based on the above analysis.