Study On The Key Problems Of Safety Evaluation Of Expressway In Mountainous Area

Mountain expressway is a section with frequent accidents and disasters.The frequent accidents are closely related to its complex topography and potential hazard sources.A large number of tailing ponds are usually distributed nearby in the construction process of mountain expressway.Because of the large number of tailing ponds and the imperfect management system,there is a huge threat to the downstream road bridges.Once these tailing ponds break,they will cause a huge impact on the mountain bridges,resulting in the damage of the bridge structure and the loss of people and property.Therefore,it is necessary to evaluate the safety of the tailing pond along the highway in mountainous area.In this paper,the mountain expressway as the research background,luanlu high-speed peripheral tailings pond and downstream bridge as the research object,the tailing pond along the mountain expressway affect the safety degree of downstream bridge risk assessment.The main research contents are as follows:(1)refer to the existing literature,summarize and analyze the relevant theories before,when and after the dam break of tailings pond,find out the important parameters that affect the operation safety of tailings pond;according to the actual situation of the project,select the appropriate formula to calculate the parameters that affect the dam break of tailings pond and the characteristic parameters of debris flow after the dam break;study the impact effect and hazard form of mineral sand debris flow on the bridge.(2)the finite element software is used to simulate the impact process of the bridge by the ore debris flow,analyze the overall response of the bridge under the impact load,and obtain the parameter values that affect the safety of the bridge structure,including the stress-strain and displacement values of the bridge pier.(3)the risk assessment matrix method is introduced into the safety assessment of the influence of the tailing dam break on the downstream bridge,the possibility of the tailing dam break is analyzed and calculated by using the triangular fuzzy number method,and then the comprehensive assessment value of the risk severity is determined based on the TOPSIS method,finally the risk assessment matrix and the risk level of the loss caused by the tailing dam break on the bridge are obtained,so as to establish a complete mountain area high Safety evaluation system of the influence of tailing dam break on the downstream bridge in expressway.Through the research on the key problems of safety evaluation of mountain expressway,it provides a reference for the safe operation of similar bridges affected by tailings pond in mountain expressway,which is helpful to reduce and prevent the occurrence of accidents and disasters in mountain expressway.