钢板结合梁斜拉桥桥面板剪力滞效应分析  

Analysis of Shear Lag Effect in Deck Slabs of Cable-Stayed Bridge with Steel Plates and Concrete Slabs Composite Girders

作　　者：宁伯伟[1] 戴慧敏[1] NING Bo-wei;DAI Hui-min(China Railway Bridge Reconnaissance and Design Institute Group Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056

出　　处：《世界桥梁》2023年第2期82-88,共7页World Bridges

摘　　要：为研究钢板结合梁斜拉桥混凝土桥面板的剪力滞效应,以泸州河东长江大桥为背景,采用MIDAS Civil软件建立主桥空间有限元模型,计算各阶段钢板结合梁混凝土桥面板剪力滞系数,与规范计算结果进行对比,并分析桥面横坡对桥面板剪力滞系数的影响。结果表明:桥塔根部截面施工阶段、通车阶段和运营阶段桥面板剪力滞系数分别约为1.4、1.203和1.46,剪力滞效应明显大于其余截面。现行《公路钢混组合桥梁设计与施工规范》(JTG/T D64-01—2015)和《公路钢结构桥梁设计规范》(JTG D64—2015)对桥塔根部截面剪力滞系数计算偏安全,对跨中截面,前者计算结果与实际受力不符,后者通车阶段、徐变后期及运营阶段的计算结果与有限元计算结果较接近,但施工阶段最大悬臂状态计算结果偏小。桥面横坡每增加1%,桥面板剪力滞系数约增大5%,工程设计中应根据实际建桥条件选择合理的桥面横坡。The study focuses on the shear lag effect in concrete deck slabs of the cable-stayed bridge with steel plates and concrete slabs composite girders. The Hedong Changjiang River Bridge in Luzhou is applied as a case. A spatial finite element model of the main bridge was developed in MIDAS Civil to calculate the shear lag coefficients of the concrete slabs in the steel plates and concrete slabs composite girders at different stages. The simulated results were compared with the values calculated by the formulas recommended in codes. And the effects of deck cross fall on the shear lag coefficient was analyzed. It is shown that at the construction stage of the tower-root cross section, as-built stage and service stage, the shear lag coefficients of the deck slabs are varying, with values of 1.4,1.203 and 1.46,respectively, which are bigger than those of other cross sections. The shear lag coefficients calculated by the formulas recommended in the Specifications for Design and Construction of Highway Steel-Concrete Composite Bridge(JTG/T D64-01-2015)and Specifications for Design of Highway Steel Bridge(JTG D64-2015)do have a certain margin of safety. For the midspan cross section, the shear lag coefficients calculated by the formulas in the former do not reflect the actual loading condition of the structure, but when calculated by the formulas recommended in the latter, the shear lag coefficients after completion of the bridge as well as at the late stage of creeping and service stage approximate the simulated results, and the calculated shear lag coefficients at the under-construction and maximum cantilever stages are smaller. Each and every 1% increase of the deck cross fall will result in about 5% increase of the shear lag coefficients. In the engineering design, it is better to select deck cross fall in accordance with the real construction conditions at the bridge site.

关 键 词：斜拉桥 钢板结合梁 混凝土桥面板 剪力滞系数 剪力滞效应 桥面横坡 有限元法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]