Subzone And Evaluation Of Geological Disaster Fatalness In The Engineering Construction Of The Railway From Baihe To Helong

Baihe-helong railroad is a part of northeast China that will play an important function in the northeast China railway network after building.The entire railroad is 106.2km.The scope for appraising risk zoning of geologic hazard is in the 1km of two sides from the railroad centerline,the two sides of the starting point and terminal point will extend lkm outwardly.The evaluating area is 216.4km~2.The evaluating area is located in the eastern mountain area of Jinlin Province.The geomorphic features show Middle-low Mountain,basaltic platform ,clastic basin and valley plsin .Most of regions that railroad will pass are bedrocks ,with well-developed vegetation,most of bare rocks can be used as building stones.The types of geologic hazards in the study area are mainly collapse ,landslide,mud-rock flow,frost-thawing and swelling.Among which,they are 20 collapes,which distribute in the middle-low mountain areas,basaltic platform,and the foot of clastic basin.In the two sides of quasi-building railroads,20-100m from the axis,tangential slope as a result of building roads,steep slope as a result of quarrying,and in the induction of the strong rainfall,it is easy to occur collapse.From the lithology,they are detrital soil,andesite,granite and basalt,the height of collapses is from 50 to 60m,degree of slope is about 35~80° ,partly straighten,some of them are bare,total length is 1402m,which belong to small size one ,degree of endanger belongs to middle or small.They are two slopes,they are slippery ascent of railway station of Helong City andslippery ascent of Tuanjie village,Longcheng County,Helong City,they are mainly distributed in theslope of Helong clastic basin margin,which are towed slide of loose accumulative clastic rocks along the surface of bde rocks,it belongs to small type and middle endanger.There are 6mud-rock flows,which are mainly distributed in the ravine or ravine mouth;the scale belongs to small and small hazard.There 3 frost-thawing and swelling,which are mainly distributed in the valley,the total length is 2500m,the scale belongs to small,and endanger is also small.The construction,low stability of tangential slope,decomposed rocks and detrital soil may cause collapse disaster,its risk makes up 77.44% of the total line,Geologic hazards are mainly collapse,landslide,mud-rock flow and frost-thawing and swelling ,among them,collapse is dominant.The discretion that evaluates dangerous degree mainly adopts synthesize method of weighted mean , in order to reflect influence factors comprehensive function for result of various functions with comprehensive factors show dangerous degree of the geologic hazards and dangerous grade . The environment factor that influence geologic hazards is complicated. On the basis of the activity characteristics of the geologic hazards , the landform , stratigraphic lithology , structural density , dissected density , seismic intensity , distributive density , hazard size and rainfall strength are selected as evaluate factors in the study area . The geologic hazard risk is divided into two grades namely middle and small one . There are 40 places of middle geologic hazard risk , the length is 20137.65m , make up 18.96% of the total length;there are 42 places of small geologic hazard risk , the length is 86062.35m, make up 81.04% of the total length.