摘要
为研究混凝土收缩、徐变对结合梁斜拉桥的影响机理及时效特性,以樟树赣江二桥(主跨400m的双塔双索面半飘浮体系结合梁斜拉桥)为背景进行分析。采用桥梁专业软件RM2006建立全桥有限元模型,对桥梁的时效影响机理、运营期不同构件的时效影响因素及不同结构体系的时效响应进行研究。研究结果表明,对于结合梁斜拉桥,桥面板收缩、徐变产生的主梁截面初始轴向应变是主梁中跨跨中下挠、边跨斜拉索松弛的主要原因,产生的主梁截面初始弯曲应变是主梁负弯矩出现的主要原因。桥面板收缩、恒载下桥面板徐变是引起边跨斜拉索松弛、主梁中跨跨中下挠的主要因素;桥塔收缩、徐变将引起桥塔附近斜拉索松弛,并使主梁产生局部负弯矩峰值。桥塔处竖向支座及辅助墩的设置会对结合梁斜拉桥的时变效应产生一定的不利影响,单纯从该角度来讲,全飘浮体系较其他体系更为合理。
To study the mechanism and time-dependant chrematistics of intluences ot the con- crete shrinkage and creep on the composite girder cable-stayed bridge, the Second Zhangshu Gan- jiang River Bridge （a semi-floating system composite girder cable-stayed bridge with double py- lons, double cable planes and with a main span of 400 m） was taken as an example and was ana- lyzed. The bridge professional software RM2006 was used to build up the finite element model for the whole bridge of the bridge, the time-dependant influential mechanism of the bridge, time-de- pendant influential factors of the different components of the bridge in operation period and the time-dependant responses of the different structural systems were studied. The results of the study show that the for the composite girder cable-stayed bridge, the initial axial strain in the cross section of the main girder caused by the concrete shrinkage and creep of the deck slabs is the main cause leading to the midspan deflection of the central span of the main girder and to the re- laxation of the stay cables at the side spans. The initial flexural strain in the cross section of the main girder caused by the shrinkage and creep is the main cause leading to the negative moment occurrence in the main girder. The concrete shrinkage of the deck slabs and the concrete creep of the slabs under dead load are the main factors causing the relaxation of the stay cables at the sidespans and the midspan deflection of the central span. The concrete shrinkage and creep of the py- lons cause the relaxation of the stay cables nearby the pylons and cause the main girder to produce the local negative moment peak values. The arrangement of the vertical bearings at the pylons and the arrangement of the auxiliary piers may cause certain adverse influence to the time-depend- ant effect of the composite girder bridge. As judged from the above-mentioned, it is considered that the full floating system is more reasonable than other systems.
出处
《桥梁建设》
EI
CSCD
北大核心
2015年第1期74-78,共5页
Bridge Construction
基金
国家973计划项目(2013CB036303)~~
关键词
斜拉桥
结合梁
收缩徐变
影响机理
影响因素
时效特性
结构体系
有限元法
cable-stayed bridge
composite girder
shrinkage and creep influential mecha- nism influential factor time-dependant characteristic
structural system
finite element method
作者简介
陈亮1975-，男，高级工程师1997年毕业于上海铁道大学桥梁与隧道工程专业，工学学士，2000年毕业于同济大学桥梁与隧道工程专业，工学硕士。研究方向：结合梁斜拉桥E-mail：chenliang@smedi．com
邵长宇1963-，男，教授级高工1984年毕业于同济大学桥梁工程专业，工学学士，2007年毕业于同济大学桥梁与隧道工程专业，工学博士。研究方向：大跨度桥梁与组合结构桥梁E-mail：shaochangyu@smedi．com
