Study On Risk Assessment And Prevention Measures Of Highway Slope And Landslide Geological Hazards In Yunnan

With the rapid development of our country's economy,highway construction tends to develop to mountainous areas,and during the construction process,a large number of side slopes distributed along the route are likely to form.The geological conditions of landslides along Yunnan mountainous highway are changeable,and instability accidents often occur during the construction period.It is an urgent problem to realize risk assessment and put forward targeted engineering protection measures in engineering construction.This paper mainly focuses on the evaluation and prevention measures of landslide geological hazards along 10 highways in Yunnan Province:(1)On the basis of regional engineering geology and literature survey,the geological data of 468 highway side landslides in Yunnan Province were collected and collated,and a database of landslide geological disasters in Yunnan was established;based on this database and the results of literature survey,the relationship between the factors affecting the landslide geological hazards and the ratio of instability was statistically analyzed to provide basic data for the evaluation method of landslide geological hazards in Yunnan area.(2)Combining the characteristics of the instability data of side landslides in the highway side landslide database of Yunnan Province and the factors affecting the stability of the road side slope,the influencing factors of geological hazards of road side landslides in Yunnan area were determined;combined with the indicators used in the highway slope stability grading method,determine the various influencing factors of the influencing factors,and establish a system of influencing factors for geological disasters in Yunnan regional highway landslides.It provides a basis for the quantitative judgment of geological hazard risk assessment of landslides along the highway in Yunnan region.(3)Based on the above research,the impact factors are divided into internal and external factors and the classification criteria of the impact factors are further defined;The fuzzy mathematics method is used to establish the influence factor membership function,the analytic hierarchy process is used to assign the weight of the influence factor,and the risk grade is obtained by fuzzy comprehensive evaluation,and the influence of the surrounding environmental safety on the geological disaster risk assessment of the roadside landslide is considered.Method is used to superimpose the geological disaster risk of surrounding landslides in the construction area of surrounding landslides,thus forming a landslide risk assessment method for highway landslides in Yunnan.(4)The types of highway slope geological disaster prevention measures and the mechanisms of various prevention methods are studied.The relationship between the excavated highway route and landslides is summarized,and the two types of highway side landslide problems are summarized,one is the excavation slope problem of the line,and the other is the landslide problem of the line passing through the ancientlandslide.According to the geological hazard risk assessment results of highway side landslides,combined with the types of prevention and control measures,different prevention and control measures are proposed for two different types of side landslides with different levels of geological disaster risks.(5)The characteristics of excavated slopes of highway routes in Yunnan Province are summarized as weathered accumulation type excavation slopes;for the reliability of the prevention and control measures of high-risk excavated slopes,a generalized model of accumulation bodies is established,using FLAC 3D finite difference method The simulation software studies the supporting effect of the disturbance caused by the excavation of the slope.The research results show that: for the excavation disturbance caused by the excavation of the slope,the displacement of micro pile is reduced to more than 50% before supporting.(6)Aiming at the problem of landslides when highway routes pass through ancient landslides in Yunnan Province,typical high-risk landslides are selected as engineering examples;for the reliability of such side landslide control measures,paper uses the unbalanced thrust method recommended in the "Code" to study the feasibility of supporting measures for selected typical highway examples.The results show that:Safety factor increased from 0.98 to 1.55,stability meets standard control standards.