跨海桥梁基础波浪力断面对比与研究  

Comparison and Research of Foundation Section of Sea Crossing Bridge Under Wave Force

作　　者：崔苗苗[1] 毕昕宇 李鑫[2] 祝兵[2] CUI Miaomiao;BI Xinyu;LI Xin;ZHU Bing(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063 [2]西南交通大学土木工程学院,成都610031

出　　处：《铁道标准设计》2024年第2期80-85,92,共7页Railway Standard Design

基　　金：国家自然科学基金项目(U1834207,52178167);四川省科技厅应用基础研究项目(2021YJ0039);中国铁建股份有限公司2020年度科技重大专项(2020-A01)。

摘　　要：桥梁基础在波浪环境下的施工安全关乎桥梁建设的稳定性,需要给予足够的重视。利用数值模拟手段,基于改进的RNG κ-ε模型,采用VOF法模拟自由液面,在保持相同迎浪断面的情况下,建立圆形、圆端形、矩形和多边形4种不同断面形式桥梁基础受波浪作用的三维数值模型,对比其受力差异,并结合流场数据加以分析。结果表明:相同波浪条件下4种不同断面形式的结构所受到水平波浪力中以圆形结构为最小,矩形结构为最大,其总水平波浪力幅值较圆形结构增大10%左右;桥梁基础结构在波浪的作用下,基础周围会受到绕流作用,使得结构部分位置处的流速增大并出现流速集中现象,在矩形结构周围这一现象最为突出,多边形结构的情况与之类似,而圆形及圆端形结构的流速集中现象则相对较弱;按规范计算得到的等效圆柱波浪力相较于数值模拟结果大23%~29%,按等效方柱计算得到的波浪力相较于数值模拟结果大10%~13%。从工程设计的角度看,采用圆弧形的结构设计有助于减小波浪荷载和削弱桥梁基础局部的流速增大与流速集中现象。The constructional safety of bridge foundation under wave condition is related to the stability of bridge construction and needs to be paid enough attention.In this paper,the numerical models of wave acting on bridge foundations with the same wave area and four different sections of circular,round-end,rectangular and polygonal are established using numerical simulation based on the improved RNG κ-ε Model.The VOF method is used to simulate the free surface.The force differences are compared and analyzed with three-dimensional flow field data.The results indicate that under the same wave condition,the total horizontal wave force of circular structure is the smallest and that of the rectangular structure is the largest with the amplitude about 10% larger than that of the circular structure.Under the action of wave,the flow will be bypassed around the foundation,which will increase the flow velocity at part of the structure and cause concentration of flow velocity.This phenomenon is most prominent around rectangular structure,similar to that of polygonal structure,while the flow velocity concentration of circular and roundend structure is relatively weaker.Compared with the numerical simulation results,the wave force of the equivalent cylinder calculated according to the code is 23%~29% larger,and the wave force calculated according to the equivalent square cylinder is 10%~13% larger.From the perspective of engineering design,the use of circular arc structure design is conducive to reducing the wave load and weakening the increase and the concentration of flow velocity.

关 键 词：跨海桥梁 桥梁基础 波浪力 结构比选 数值模拟 

分 类 号：U448[建筑科学—桥梁与隧道工程] TV139.2[交通运输工程—道路与铁道工程]