Study On The Failure Mechanism Of Highway Slope Within Foliated Rockmass Along The S220 Highway In Lijiang City,Yunnan Province

The geological structure of Yunnan area is complex,and geological disasters occur frequently.Among them,the landslide and collapse caused by slope damage are the most harmful.Through the geological survey of Yunnan province between Ninglang county and Yongsheng County Road S220,found in two counties at the boundaries of rock slope and landslide are generally foliated.Schistositilization "schistosity" plays a role in destruction of highway slope.The section of the highway is three layers of winding highway,the width of the highway is about 4 meters,and the terrain is complex,the elevation of more than 2500 meters,often landslides,easily lead to traffic disruption.Therefore,the slope of the highway is selected as the research object,and the field geological survey,slope mapping and landslide statistics are carried out.On the slope of the field survey found that slope development to three groups "schistosity".In the same slope "schistosity" occurrence roughly consistent with the rules.Intensive "schistosity "development in rock mass with high shale content,less than 5 cm spacing schistosity ",while in the low mud content of rock slope in "schistosity" is greater than 5 cm spacing.Foliated rock and soil slope caused structural damage,a fragmentation structure or granular structure,the overall strength is greatly reduced.The slope with foliated features,its damage often from slope development "schistosity" position began to accelerate the process of deformation and failure,failure of the slope,become the main control factors of the development of slope rock strength and slope deformation and destruction.In the study area,the typical slopes were measured on the occurrence of "schistosity" stereographic projection,advantage analysis of structure caused by the slope surface,and the use of Flac3 D on the foliated rock slope stress and strain analysis by strength reduction method,get the slope rock stress distribution and deformation characteristics as well as possible the site of damage."The occurrence of a great influence on the formation of" shear strain increment,when occurrence and slope "schistosity" tendencies,damage size affect the inclination of the position,tendency to affect the slope after excavation damaged parts.And combined with the local climate and lithology,slope engineering geological conditions in the region summary schisteous slope failure process.