Forecast Of Collapse Rockfalls Threat Range And Study On Railway Disaster Mitigation Measures

Collapse is widely distributed in our country,it is the second-largest geological disasters except landslide.Its size is generally small,but It happens in more places,its frequency is higher,and prevention and early-warning of collapse is difficult.Collapse and rockfall hazards have been involved in the various fields of national economy and people's life.The harmful consequences caused by both direct impact and indirect impact cause casualties and economic losses every year.Railway has always been the project in which the rockfall hazards are most frequent and serious.Collapse and rockfalls often destroy lines,disrupt traffic,smash the station house,damage yard,destroy railway bridges and other facilities,cause roll-over and people death.Therefore,summarize the influence factors of collapse rockfalls,and their disaster modes for railways to draw the principles of railway location,put forward the railway bypassing distance and rockfall area protection measures to reduce rockfall impact of disasters on the railways.In this paper,the research contents and conclutions are:1.Mainly from the climate,topography,geological structure,earthquake activity,human factors and external stress factors six aspects,analyzes the influence of collapse rockfalls happened.Summarize the distribution of rockfalls in China.2.Based on the investigation and statistics,find the situation of major railway suffered rockfall disaster in China.Through the analysis of the typical case,refine disaster mode of collapse rockfalls on railway engineering.3.On the basis of summarizing the predecessors' research,adding some new content form a complete railway location technology system in collapse rockfalls region.The principles of railway location through collapse rockfalls region mainly include:First of all,pay attention to geological line selection,find out the engineering geological conditions in the area,make the direction of the line to avoid paralleling with the direction of the tectonic line.The line location should be away from the fault location and the bank on which level or the tendency of major joint surface is same as hillside tendency as far as possible.In the mountain valleys and the region in which lithology have large difference,high slope excavation should be reduced.When through high earthquake intensity collapse rockfalls region,the line should be away from the active fault zone as far as possible.Secondly,depending on the type and size of rockfall hazards,lines can use the tunnel scheme,the avoidance scheme or protective passing scheme by technical and economic comparison.4.Based on the large finite element software Abaqus CAE,rockfall collisions with slope surface model is established.Research the rockfalls threat range of railway in different slope shape,slope height and slope conditions.By calculating,provided a method for people to estimate rockfall distance quickly in a tabular form5.Summarize the main engineering measures for the prevention and control of collapse rockfall.Analyse the characteristics and applicable conditions of various collapse rockfall prevention engineering.Introduce the development of the thoughts of collapse rockfalls prevention and engineering measures,and the latest control methods and products.