Classification And Risk Assessment Of Local Scour For Bridge Foundation In Mountainous Area

The bridge foundation in the river channel of mountain rivers changes thenatural flow pattern of the river,leading to local scour of the bridge foundation and seriously threatening the safety of the bridge.Especially for bridges built on mountain rivers,the current has stronger scouring ability and higher potential danger.At present,there are few studies on the local scour of bridge foundation in mountainous regions.Therfore it is particularly important to classify the local scour of bridge foundation in mountainous regions to grasp their scour characteristics and conduct risk assessment research.In this paper,the local scour mechanism and influencing factors of bridge foundation are deeply summarized and analyzed.Based on this,on-site field investigations were conducted on the partial scouring of bridges on the Pihe River and Changhe River.Based on this,on-site field investigations were conducted on the partial scouring of bridges on the Pihe River and Changhe River.According to the field investigation and collected historical data,and in view of the characteristics of local scour of mountain rivers,the local scour classification of bridge foundation in mountain areas is proposed,which takes riverbed material as the main consideration.On the basis of on-site investigation and classification,this paper establishes an evaluation index system for local scour of bridge foundation in mountainous regions.Fuzzy comprehensive evaluation method based on AHP is used to establish a comprehensive evaluation model to evaluate the the 2nd Chang He Bridge.In addition,quantitative evaluation and analysis are carried out by using numerical simulation method,and combined with on-site investigation,the results of the established risk evaluation model were compared and verified.The comparison results show that the established comprehensive evaluation model is in good agreement with the actual situation and the results of numerical simulation.