摘要
跨海桥梁基础长期受波浪、水流作用,波流耦合作用于高桩承台时,会产生复杂的水动力荷载,其压力分布特性与常规波浪存在显著差异,给桥梁结构设计带来了巨大挑战。为研究跨海桥梁矩形截面高桩承台迎浪面在波流耦合作用下冲击压力的空间分布特性,利用计算流体动力学软件FLOW-3D建立了基于雷诺时均(RANS)方程和k-ε湍流模型的三维数值水槽,通过边界造流和质量源造波方法实现了对波流耦合作用的数值仿真;并通过对比前人试验,验证了上述模型的准确性。数值模拟了不同波高、承台净空和波流条件下的水平波流力时程和波压力空间分布,分析了波流同向、反向条件下的承台迎浪面波压力空间分布特征。基于数值模拟结果,分别建立了以波高和承台净空为参数的波流同向和反向条件下矩形截面高桩承台迎浪面水平波压力空间分布的数学表达式。研究结果表明:(1)波流同向时承台所受波流力变化规律与纯波条件相似,但波流反向时产生的最大波流力可达纯波条件的4倍;(2)承台迎浪面波压力分布受波高、净空和越浪影响大;(3)提出的矩形截面高桩承台迎浪面水平波压力空间分布的数学表达式与数值模拟结果吻合较好,且计算效率高。相关研究成果对于合理开展跨海桥梁设计具有重要理论意义和工程实用价值。
The foundations of sea-crossing bridges are subjected to long-term waves and current loads.When the interacting waves and current loads impact the elevated pile cap,complex hydrodynamic loads with pressure distribution characteristics that are significantly different from those of conventional waves are generated.This poses significant challenges for the design of bridges.Therefore,a three-dimensional numerical wave tank(NWT)was established in this study based on the Reynolds time-average(RANS)equation and k-εturbulence model using the computational fluid dynamics(CFD)software FLOW-3D to investigate the spatial distribution characteristics of the wave-current impact pressure on the upstream surface of an elevated pile cap with a rectangular cross-section.A numerical simulation of the wave-current interaction was then realized using the inflow boundary and mass source wave generation method,and the developed NWT was validated using experimental results.Subsequently,the spatial distributions of the horizontal wave force and wave pressure were simulated considering different wave heights,cap clearances,and wave-current conditions,and the spatial distribution characteristics of the wave pressure on the upstream surface of an elevated pile cap were investigated considering waves with currents in the same and opposite directions.Based on the numerical simulation,mathematical expressions of the spatial distribution of the horizontal wave pressure on the upstream surface were derived as a function of the wave height and clearance of an elevated pile cap with a rectangular cross-section considering waves with currents in the same and opposite directions.The major findings include:①the trend in the hydrodynamic load is similar in the elevated pile cap under pure waves and waves with the current in the same direction,whereas the maximum load of the cap under waves with the current in the opposite direction is four times that of the pure wave condition.②The spatial distribution of the horizontal wave pressure on the ups
作者
魏凯
胡楷宇
周聪
WEI Kai;HU Kai-yu;ZHOU Cong(Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;Zhejiang Institute of Communications Co.Ltd.,Hangzhou 311100,Zhejiang,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2023年第10期357-367,共11页
China Journal of Highway and Transport
基金
国家自然科学基金优青项目(52222804)。
关键词
桥梁工程
高桩承台
数值模拟
波流耦合
冲击压力
数学模型
bridge engineering
elevated pile cap
numerical simulation
wave-current interaction
impact pressure
mathematical model
