The Development Distribution Of Geological Hazards In The Slope Of Wenma Expressway And Risk Assessment And Judgement

Wenma expressway is located in west sichuan basin,qinghai-tibet plateau hilly region to the northwest sichuan longmen mountain edge of trapezoid transition zone,the topography is complex,geological structure,the earthquake intensity is high,the geological disasters are well-developed,and wenma expressway in the construction process have produced a large number of geological disasters.Based on the data collected from the investigation and design of the slope geological hazards along the Wenma highway,First of all,the distribution and influence factors of geological hazards along the slope of Wenma highway are studied.Secondly,different types of slope geological disasters,using fuzzy comprehensive AHP to evaluate the risk of geological disasters on the slopes of different types,and establish the risk level of regional geological disasters.Finally,the potential classification criteria for various slope geological disasters are set up from the geological evolution model.The main achievements and achievements are as follows:(1)Through the study on the development,distribution and influencing factors of geological disaster points along the Wenma Expressway,there are three types of geological disasters on the Wenma Expressway: landslides and unstable slopes,dangerous rocks,and debris flows.Its developmental distribution has the characteristics of segmentation and relative concentration in spatial distribution.Its subsection refers to the distribution of geological hazards on Wenma highway,which can be divided into two sections: Wenchuan ～ Li County,relatively dense disaster spots,earthquakes active,mainly in dangerous rock,landslides and unstable slopes;Li County ～ Malcon,relatively sparse disaster points,rich rainfall,vegetation development,with mudslides,dangerous rock the lord.It has seasonal and repeatability in time distribution,and its influencing factors include slope effect,elevation effect,stratigraphic lithology effect,fault distance effect,hydroclimate effect and human engineering activity effect.(2)In response to the Wenma Expressway landslides and unstable slopes,dangerous rocks,and mudslides,3 different types of geological disasters and excavation of high slopes,starting from factors such as the terrain and geomorphology,,geological conditions,rainfall hydrology,external influence factors,historical activities and signs of slope deformation,different evaluation indexes were selected to establish different evaluation models,According to the established model,different types of geological hazards are evaluated for hazards.Selection of slope,slope height,aspect,vegetation coverage,formation lithology,geological structure,the slope body’s own structure,landslide volume,slippery surface characteristics,rainfall effect,earthquake action,slope-to-water system distances,human engineering activities,and slope deformation and destruction signs totaled 14 indicators.Landslide and unstable slope risk assessment models were established.Through the risk assessment of typical 19 landslides and unstable slopes on the Wenma expressway,4 are high hazards,11 are medium hazards and 4 are low hazards.Selection of slope,slope height,stratum lithology,slope structure type,geological structure,annual rainfall,surface water scour,groundwater effect,seismic intensity and ground motion peak acceleration are 10 indexes,and the risk assessment model of excavation high slope is established.Through the risk assessment of 13 typical excavation high slopes on the Wenma Expressway,3 are high risk and 10 are medium risk.Selection of lithological grade,relationship between dominant structure surface and surface surface,slope,slope height,vegetation coverage,annual rainfall,surface water erosion,groundwater effect,seismic intensity,earthquake peak acceleration,historical strong earthquake occurrences number are 11 indexes,the establishment of dangerous risk assessment model.Through the risk assessment of 13 typical dangerous rocks on the Wenma Expressway,4 are high risk,6 are medium risk and 3are low risk.Selection of longitudinal channel bed slope,watershed area,vegetation coverage,lithology grades,dynamic storage of loose material,earthquake effect,annual rainfall,surface water erosion,action of groundwater,debris flow frequency,a maximum amount out of a total of 11 indicators,establish the risk assessment model of debris flow.According to the risk assessment of 7 typical debris flows on the Wenma highway,2 are high risk,3 are moderate risk,and 2 are low risk.(3)According to the characteristics of Wenma highway landslide and unstable slope,danger rock and debris flow,summarizes the Wenma highway potential landslide has 4 types respectively,rock dumping deformation body,deposit layer earth landslide,shallow surface landslide,stream sand slope.There are 3 types of potential dangerous rock,which are falling dangerous rock mass,dumping type critical rock and slide type dangerous rock.There are 3 types of debris flow,which are slope type debris flow,valley type + dilute debris flow,valley type+ viscous debris flow.For the landslides and dangerous rocks,4 different types of potential landslides and 3 different types of potential dangerous rocks are established by using the method of geological evolution analysis,from the initial state of the slope,the stage of aging deformation,the progressive deformation and failure stage and the post failure stage.For debris flow,3 different types of potential debris flow criteria were established from the young,puberty,strong,old,stop,or terminating.