预应力刚构桥施工阶段腹板斜裂缝分析及其加固  

Study on Slant Cracks on Webs of Prestressed Rigid Frame Bridge during Construction and its Reinforcement

作　　者：李黎[1,2] 叶志雄[1,2] 陈元坤[1,2] 

机构地区：[1]华中科技大学土木工程与力学学院,湖北武汉430074 [2]华中科技大学控制结构湖北省重点实验室,湖北武汉430074

出　　处：《工程抗震与加固改造》2010年第5期96-100,106,共6页Earthquake Resistant Engineering and Retrofitting

基　　金：交通部西部交通建设科技项目(200431800024)

摘　　要：某连续刚构桥在箱梁悬臂施工时腹板出现规则的斜向裂缝。针对该桥从设计、材料、施工等方面进行了裂缝产生原因分析。通过在箱梁腹板预埋混凝土应变计进行应力监测,以及用Ansys软件对其腹板主拉应力进行了空间有限元分析,认为竖向预应力钢筋和箍筋配置偏少以及纵向预应力钢筋位置设置不当是导致箱梁腹板出现斜裂缝的最主要原因。最后,提出了改善设计的具体建议和裂缝的处理措施。后续实测表明,避免这种斜裂缝出现所采取的措施是有效的。Inerratic slant cracks appeared on the box girder webs of one continuous rigid frame bridge during cast in place cantilever.The causes leading to the crack problems are studied from aspects of design,material,construction and so on.The stress in the webs is measured by embedded concrete strain gauges,and web principle stress is analyzed with spatial finite element method by using ANSYS software.Then the most main reason caused the slant cracks on webs are found to be vertical prestressed reinforcement and stirrups shortage,longitudinal prestressed reinforcement improper location.At last,some suggestions and measures for avoiding the slant cracks are put forward.Continued measurement shows that the treatments are effective.

关 键 词：预应力刚构桥 斜向裂缝 应力监测 有限元分析 加固 

分 类 号：U445.7[建筑科学—桥梁与隧道工程]