铁道科学与工程学报2024，Vol.21Issue(4)：1482-1494,13.DOI:10.19713/j.cnki.43-1423/u.T20231003
间距对公铁双幅主梁气动特性影响的试验研究
Experiment study on spacing effect of the aerodynamic characteristics of twin parallel decks for rail-cum-road bridges
摘要
Abstract
In order to study the spacing effect on the aerodynamic characteristics between the asymmetric parallel girders of rail-cum-road bridges,the wind tunnel test with twin asymmetric section models was carried out on the background of the main beams of a long-span twin asymmetric parallel girders of rail-cum-road bridge to study the aerodynamic characteristics,the wind pressure distribution and flow characteristics of the highway and railway girders under different wind directions in the spacing range of L/Br=0.2～2.0.The results show that regardless of α=0° or α=180°,the aerodynamic coefficient,surface wind pressure distribution and flow pattern of the upstream girder are less affected by the spacing,which is also similar to that of a single girder.However,the aerodynamic characteristics of the downstream girders are greatly affected by the spacing,and are completely different from that of a single girder.The flow pattern around the gap changes with increasing spacing,and the aerodynamic coefficient,mean wind pressure coefficient curve and fluctuating wind pressure coefficient curves of the downstream girders for highway and railway also show completely different laws.The larger the spacing,the closer the aerodynamic characteristics and flow pattern are to that of a single girder.Highway girder has stronger streamlines than railway girder.This difference in aerodynamic shape leads to different aerodynamic interference characteristic of twin asymmetric girders under two opposite wind directions,and the influence of spacing on them is completely different.For example,when α=0° and L/Br=0.2～2.0,the flow pattern for the upper surface of the whole girder is"Single-body regime",but when α=180°,the flow pattern for the upper surface of the whole girder is"Reattachment regime".Depending on the spacing,the wake of the upstream highway girder is attached to the downstream railway girder in different positions,which can be subdivided into two different flow modes.This study can provide reference for the spacing design of the same type of twin asymmetric parallel decks bridge.关键词
间距效应/双幅桥/公铁平层桥/气动干扰/风压系数/风洞试验Key words
spacing effect/twin asymmetric parallel decks/rail-cum-road bridges/aerodynamics interference/wind pressure coefficient/wind tunnel test分类
交通工程引用本文复制引用
刘路路,何旭辉,邹云峰,杨甲锋..间距对公铁双幅主梁气动特性影响的试验研究[J].铁道科学与工程学报,2024,21(4):1482-1494,13.基金项目
国家自然科学基金资助项目(52078504,U1934209,51925808) （52078504,U1934209,51925808）
湖南省自然科学基金资助项目(2022JJ10082) （2022JJ10082）
湖南省科技创新计划项目(2021RC3016) （2021RC3016）
中南大学中央高校基本科研业务费专项资金资助项目(CX20220238,2022ZZTS0152) （CX20220238,2022ZZTS0152）
