简支变连续桥负弯矩区长期性能研究  

Study on Long-term Performance of Negative Moment Region of Simply Supported Variable Continuous Bridge

作　　者：邓园园 DENG Yuanyuan(Hunan Province Highway Design Co.,Ltd.,Changsha,Hunan 410076,China)

机构地区：[1]湖南省公路设计有限公司,湖南长沙410076

出　　处：《公路工程》2020年第3期229-233,共5页Highway Engineering

基　　金：湖南省自然科学基金资助项目(2019JJ50130)。

摘　　要：简支变连续梁桥同时具有简支梁和连续梁的特点,墩顶负弯矩区受力状态是该类桥梁要点,负弯矩区的配筋形式、有效应力、收缩徐变等参数均会对弯矩区长期性能产生影响。以某4跨40 m简支变连续T梁桥为背景,利采用MIDAS/civil软件建立全桥分析模型,讨论负弯矩区不同配筋形式、不同收缩徐变模式的影响。分析表明:不同的收缩徐变模式会产生不同的结果,收缩徐变产生的长期效应会较大影响负弯矩的应力分布,合理的配筋可有效限制简支变连续桥梁负弯矩区拉应力,设计阶段应合理设计墩顶负弯矩钢束,使其既能限制截面上缘拉应力又经济合理。Simply supported variable continuous beam Bridges have the advantage of simply supported beam and continuous beam at the same time.The stress state of negative moment zone at the top of pier is the key point of this type of bridge.In this paper,a 4-span 40m simple-supported continuous T-beam bridge is taken as the background,and MIDAS/civil software is used to build the whole bridge analysis model to discuss the influence of different reinforcement forms and different shrinkage and creep modes in the negative moment area.The following main conclusions:the long-term effects caused by shrinkage and creep is more negative bending stress distribution,the influence of different shrinkage creep models for a greater influence on the stress calculation results,the reasonable reinforcement scheme scheme can effectively restrict simply-supported continuous bridge tensile stress in the negative moment region,in the support section on the edge of the compressive stress is increased with the increase of number of prestressed reinforcement,the design phase should be reasonable design of negative bending steel pillar top,beam can make the limit tensile stress in the flange on the cross section and economic and reasonable.

关 键 词：有效预应力 简支变连续桥梁 负弯矩区 收缩徐变 截面应力 

分 类 号：U441.1[建筑科学—桥梁与隧道工程]