台阶型沉井水动力特性及局部冲刷影响研究  

Study of Influence of Setting Stepped Caisson on Hydrodynamic Property of Surrounding Water and Local Sour

作　　者：徐华[1] 闫杰超 孙永华 闻云呈[1] 张胡[2] XU Hua;YAN Jie-chao;SUN Yong-hua;WEN Yun-cheng;ZHANG Hu(Nanjing Hydraulic Research Institute,Nanjing 210029,China;China Railway Major Bridge Reconnaissance & Design Institute Co. ,Ltd. ,Wuhan 430056,China;Jiangsu Provincial Transportation Engineering Construction Bureau,Nanjing 210004,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]中铁大桥勘测设计院集团有限公司,湖北武汉430056 [3]江苏省交通工程建设局,江苏南京210004

出　　处：《世界桥梁》2022年第2期64-70,共7页World Bridges

基　　金：国家自然科学基金项目(51779149);交通运输行业重点科技项目(2019-MS1-011);中国中铁股份有限公司科技研究开发计划项目(2019-重点-07)。

摘　　要：为了解台阶型沉井附近水动力特性及沉井台阶位置对局部冲刷的影响,以优化沉井结构,以某桥大型台阶型沉井为背景,通过流体计算软件CFD建立三维定床水动力模型,分析该沉井台阶设置对水流流速和流速矢量、湍流动能、床面切应力等沉井附近水动力特性的影响规律;通过物理模型动床试验,分析台阶位置对最大局部冲刷深度的影响。结果表明:通过数值模拟分析,沉井台阶位置位于床面或以下对其附近的水动力特性影响较小;通过物理模型动床试验,沉井的台阶位置位于床面、床面以下0.6h、0.81h(h为水深)处时,其最大局部冲刷深度相较于无台阶沉井基础的最大局部冲刷深度的减冲率分别为5.6%、18.8%与19.9%。The large-scale stepped caisson of a real bridge is used as a case to investigate the hydrodynamic property of the caisson of such type and the influence of the location of caisson step on the local scour effect.A 3D fixed-bed hydrodynamic model was established by software CFD to examine influence law of setting stepped caisson on the hydrodynamic property of surrounding water,including water flow velocity and flow velocity vector,turbulent kinetic energy and bed shear stress.Moving-bed tests on physical model were carried out to analyze the influence of step locations on the maximum local scour depth.The results of numerical simulation demonstrate that arranging the step of caisson at and/or below the bed can bring minimal influence on the hydrodynamic property of the surrounding water.According to the moving-bed tests on physical model,arranging the step of caisson at the bed level and at the locations of 0.6h and 0.81h(h stands for water depth)below the bed,the maximum local scour depth reduction rates can be reduced by about 5.6%,18.8%and 19.9%,respectively,compared with the caisson foundation without step.

关 键 词：桥梁工程 台阶型沉井 水动力特性 局部冲刷 减冲率 三维模拟 模型试验 

分 类 号：U443.131[建筑科学—桥梁与隧道工程]