槽形钢_混凝土组合梁及其应用前景初探_聂建国

土木工程学报CHIN A CIVIL ENGINEERING JOURNAL

第41卷第11期2008年11月

Vol.41No.11Nov.

2008

基金项目：国家自然科学基金（50778103）、北京市自然科学基金

（8071003）和长江学者和创新团队发展计划(IRT00736)

作者简介：聂建国，博士，教授收稿日期：2008-03-31

槽形钢-混凝土组合梁及其应用前景初探

聂建国

吴丽丽

樊健生

吕坚锋

（清华大学，北京100084）

摘要：提出一种适用于轨道桥梁的新型槽形（Ｕ形）钢-混凝土组合下承式桥梁，它是指在槽形截面的钢梁内侧浇筑混凝土，钢板与混凝土通过抗剪连接件组合成整体共同工作。这种结构形式不仅继承了传统混凝土槽形梁结构的特点，而且具有许多自身的优点，钢板可以代替模板，故无需模板或使用较少模板进行施工；结构受拉区外包钢板，既避免了混凝土裂缝暴露，又具有较好的防撞功能，结构的耐久性好。下层钢板在横向和纵向均可以充分发挥抗拉强度，大大简化了构造，减少钢筋绑扎、焊接以及横向预应力张拉的困难。对这种槽形组合梁截面形式的比选进行了初步有限元分析。结果表明，截面各参数对结构受力性能的影响程度不同，其中混凝土底部纵向肋宽度、混凝土翼缘厚度及腹板高度等是较敏感因素；温度和混凝土收缩徐变对结构受力性能的影响也较大。在竖向荷载的作用下钢梁底板和混凝土底板的中面纵向应力沿板宽的分布均表现出一定的剪力滞后现象。还指出关于这种新型组合梁今后值得进一步研究的问题。关键词：槽形钢-混凝土组合梁；轨道桥梁中图分类号：ＴＵ３１８＋．１

文献标识码：Ａ

文章编号：１０００-１３１Ｘ（２００８）１１-００７８-０８

Preliminary study of channel steel -concrete composite beam and application

Nie Jianguo Wu Lili Fan Jiansheng L üJianfeng

（Tsinghua University,Beijing 100084,China ）

Abstract:A new type of channel （U -shape ）section （steel -concrete ）composite girder bridge is presented.It is a component that concrete is cast at the interior of the steel -concrete channel section steel beam prefabricated from steel plates,and the steel plates and the concrete are integrated through shearing connectors and work together.While inheriting the characteristics of traditional concrete channel beams,this type of structure possesses its own merits,including that with steel plates substituting formwork,construction may proceed with few or no formwork.The tension areas of the structure are wrapped with steel plates to improve the durability,for it not only avoids the exposure of concrete cracks,but also provides protection from impact.The tensile strength of the steel plate at the bottom can be made full use for both the transversal and the longitudinal directions,which greatly simplifies the fabrication of the structure,including make the assembling,welding of reinforcement,and the transversal tension of the prestressing tendon easier.A series of design methods,including calculation methods for flexural capacity,longitudinal and vertical shear resistance,torsion behavior,rigidity,deformation,crack resistance,and creep,as well as the construction details and techniques,will be proposed on the basis of experimental and theoretical studies.A preliminary finite element analysis on the sectional types is carried out.It is shown that the parameters of the section have different impacts on the performance of the paring with others,the width of the longitudinal rib of the bottom concrete,the flange thickness and the web height of the concrete are relatively more sensitive factors.In addition,temperature and contraction,creep of the concrete also have much influence on the structural behavior.Shear lag is exhibited to some extent for the longitudinal middle -plane stress distribution along the direction of width of the bottom panel of the steel girder and concrete under the vertical loads.Keywords:channel steel -concrete composite beam;railway bridge E -mail:niejg@