An energy conservation model for the temporal evolution of local scour depth at bridge piers during floods  

作　　者：Qigang Chen Ran Huang Huilan Zhang Qiang Zhong 

机构地区：[1]School of Civil Engineering Beijing Jiao tong University,Beijing,China [2]Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University,Beijing China [3]Beijing Engineering Research Center of Soil and Water Conservation,Beijing Forestry University,Beijing China [4]College of Water Resources & Civil Engineering,China Agricultural University,Beijing China

出　　处：《International Journal of Sediment Research》2024年第4期654-669,共16页国际泥沙研究（英文版）

基　　金：financially supported by the Key Research,Development,and Transformation Program of Qinghai Province China(Grant No.2021-SF-161);the National Natural Science Foundation of China(Grant No.52279056);the Fundamental Research Funds for the Central Universities(GranNt o.2020JBM044).

摘　　要：Local scour at piers is one of the primary causes of bridge failures.The prediction method for the temporal evolution of local scour depth at bridge piers during floods was investigated based on the law of conservation of energy.The energy transfer process between water flow and sediment during the local scour process at bridge piers was theoretically analyzed based on the current understanding of the mechanism of local scour.The results show that there is a dynamic equilibrium relation between the energy loss of water flow and the energy gain of eroded sediment during the local scour process.This relation is applied to establish a mathematical model for predicting the temporal evolution of scour depth.This model has only one parameter,which is the energy transfer efficiency between the water flow and the eroded sediment.The energy transfer coefficient is mainly determined by the flow intensity under clear-water scour conditions,and an empirical formula for calculating it is obtained.The proposed model was evaluated using measured data of local scour depth under both well-controlled flows and natural floods.The results show that the model is able to provide satisfactory predictions and its performance can be further improved by including more sophisticated methods for determining the critical velocity for incipient scour.Meanwhile,the performance of the model is insensitive to the possible uncertainties introduced when determining the energy transfer coefficient.The research results indicate that it is feasible to establish a theoretical prediction model for accurately forecasting the local scour depth at bridge piers.

关 键 词：Local scour Bridge piers Time-dependent scour depth Floods Estimation model 

分 类 号：TV13[水利工程—水力学及河流动力学]