Mountain Highway High Fill Subgrade Total Life Cycle Risk Assessment

Following the development of the western region,the western mountainous area highway mileage is growing rapidly,and in the process of construction,due to linear design and other factors,inevitably through some of the complex terrain of the mountain and produce a large number of high fill subgrade.High fill subgrade with high filling height,complex geological conditions,relatively large weight and so on,often prone to slope stability damage.In recent years,the practice shows that landslide disaster and roadbed subsidence are particularly prominent in high fill subgrade disasters in mountainous areas,causing great losses to the social economy.Therefore,the risk assessment of high embankment subgrade disaster is of great significance to disaster management and monitoring and early warning,Based on the national science and technology support project "Southwest mountain trunk road subgrade catastrophe process control theory and dynamic control technology research" as the basis,to carry out relevant research,introduced the concept of total life cycle,and in the process of constructing the risk assessment index system of the high-filling embankment of the mountainous highway,the high subgrade disaster as a dynamic process,the dynamic evaluation of roadbed stability in the total life cycle is carried out,and the risk of high embankment roadbed in mountainous highway is graded.This is a traditional mountain road high fill roadbed disaster prevention and control technology a breakthrough.The main research results as follows:(1)The main influencing factors of landslide and subgrade subsidence in high embankment subgrade are analyzed in detail.At the same time,the concept of high filling roadbed total life cycle is introduced,that is,the survey and design stage,construction stage and operation stage of high fill roadbed are defined as the full life cycle of the high fill subgrade.(2)Based on the theory of analytic hierarchy process(AHP),according to the selecting principle of evaluation index and the experience of many experts,in the total life cycle of high embankment subgrade,the evaluation indexes of landslide and roadbed subsidence are selected in stages,and the risk evaluation index system of typical geological disaster landslide and roadbed subsidence in high filling subgrade is established in the total life cycle.(3)According to the principle of the high risk of the high embankment subgrade,the risk of each evaluation index is divided into four grades and assigned respectively.Because of the different factors in different stages of the different degree of disaster risk and the same kind of factors at different stages of the risk of disaster is also different,combined with the actual situation and the recommendations of the experts,the evaluation of the indicators were quantified,the risk classification index of landslide hazard and roadbed subsidence is established in stages throughout the total life cycle of high fill subgrade.(4)On the basis of the previous research,according to the correlation between the evaluation indexes of each stage,the weight of the evaluation index of the high risk of the high embankment subgrade is calculated by the analytic hierarchy process.The risk assessment model of landslide and roadbed subsidence is established.At the same time,the high risk of high embankment is divided into low-risk,medium-risk,high-risk and high-risk four grades.According to the result of evaluation model of the calculation,determine the high fill subgrade disaster risk level.(5)Combined with chongqing nanchuan ~ guizhou daozhen highway K29 + 800 ~ K30+ 200 section of the embankment and chongqing fengjie ~ YunYang highway K1362 + 390 ~ 485 period of the actual situation of embankment,the established model are verified,the evaluation results with the field investigation data disaster history comparative analysis,find that the results of evaluation and the results have good consistency.