主桥架设过程中引桥混凝土临时支座损伤分析  

Damage Analysis of Approach Bridge Concrete Temporary Bearings During the Erection of the Main Bridge

作　　者：王炎[1] 胡光晓 王晓阳 杨予[1] 罗潇 Wang Yan;Hu Guangxiao;Wang Xiaoyang;Yang Yu;Luo Xiao(School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou 310018,China;Zhejiang Institute of Communications Co.,Ltd.,Hangzhou 310030,China;The Second Harbor Engineering Company,Chongqing 401120,China)

机构地区：[1]浙江理工大学建筑工程学院,杭州310018 [2]浙江数智交院科技股份有限公司,杭州310030 [3]中交第二航务工程局,重庆401120

出　　处：《科技通报》2023年第10期90-97,共8页Bulletin of Science and Technology

基　　金：浙江省交通运输厅科研计划项目(2019022)。

摘　　要：临时支座是简支变连续梁桥体系转换中的重要构件,但在体系转换完成后应该尽快拆除,实际施工中会存在拆除滞后或拆除不完整的现象,在外部荷载作用下会对临时支座自身的力学性能以及主梁、桥墩等构件产生影响。本文对温州瓯江北口大桥南引桥临时支座开裂现象进行原因排查,根据现场实际施工情况,考虑临时支座未及时拆除情况下悬索桥锚碇偏转工况和环境温度变化工况对临时支座受力的影响。首先利用有限元软件Midas/Civil建立整体模型,计算未拆除临时支座情况下锚碇偏转和环境温度作用对控制截面的荷载,再引入混凝土塑性损伤模型对临时支座进行局部实体建模,分析2种工况下钢筋混凝土临时支座的应力及损伤情况。结果表明:临时支座在2种工况下,最大拉应力均达到C50混凝土的拉应力容许值,受拉损伤因子较大部位最先集中在临时支座与上部梁体以及下部桥墩交界处,并逐渐向临时支座中间区域发展形成斜向45°的高损伤区域。实际工程中裂缝的发展走向和混凝土拉伸损伤云图的发展走向基本保持一致,表明有限元参数取值可靠。在临时支座未拆除的边界条件下,这2种外部荷载均会导致临时支座发生损伤破坏。研究可为桥梁工程中的裂缝分析及规范施工提供一定的参考。The temporary bearing is an important element in the conversion of simple to continuous beam bridge system,but it should be dismantled as soon as possible after the system conversion is completed.The article investigates the causes of temporary bearing cracking on the south approach bridge of Wenzhou Oujiang River Bridge,and considers the effects of anchor deflection and ambient temperature change on the temporary bearing under the condition that the temporary bearing is not removed in time,and firstly uses the finite element software Midas/Civil to establish the overall model to calculate the load on the control section under the condition that the anchor deflection and ambient temperature are not removed.Then,we introduced the concrete plastic damage model to model the temporary bearing as a local entity and analyzed the stress and damage of the reinforced concrete temporary bearing under the two working conditions.The results show that the maximum tensile stress of the temporary bearing reaches the allowable value of the tensile stress of C50 concrete under both conditions, and the larger tensile damage factor is firstly concentrated at the junction of the temporary bearing with theupper beam and the lower pier, and gradually develops to the middle area of the temporary bearing to form a high damagearea with an oblique direction of 45°. The development direction of cracks in actual engineering and the developmentdirection of concrete tensile damage clouds basically remain consistent, indicating that the finite element parameters arereliable. Under the boundary conditions where the temporary bearings are not removed, both external loads lead to damageof the temporary bearings. The study can provide some reference for the analysis of cracks in bridge engineering and thespecification of construction.

关 键 词：简支变连续梁桥 体系转换 临时支座 混凝土损伤 应力分析 

分 类 号：TU312[建筑科学—结构工程]