大跨度连续刚构桥预应力束沿程应力试验研究  

Test Study of Along-Path Stress of Prestressing Strands of Long Span PC Continuous Rigid-Frame Bridge

作　　者：叶志华[1] 张高朝[1] 路为[1] 

机构地区：[1]湖北沪蓉西高速公路建设指挥部,湖北恩施445000

出　　处：《桥梁建设》2009年第5期21-23,27,共4页Bridge Construction

摘　　要：为了解预应力混凝土结构中预应力束的实际有效预应力沿程分布情况,选取野三河大桥大跨度连续刚构中的典型预应力束,设计制作近百米长的预应力钢筋混凝土模型进行试验研究。试验结果表明,预应力束的沿程应力分布从张拉端向钢束中部(两端张拉)或向被动端(一端张拉)逐渐减小;同一预应力束中不同钢绞线之间受力不均匀,且差别较大;为获得相对较大的有效预应力,宜采用两端张拉,并选用塑料波纹管。To well understand the along-path distribution of the actual and effective stress of prestressing strands in prestressed concrete （PC） structure, the typical prestressing strands used for the long span PC continuous rigid-frame structure of Yeshan River Bridge were selected and the model of a prestressed concrete beam approximately 100 m in length was prepared and tested. The results of the test show that the stress distribution along the paths of the strands gradually decreases from the jacking ends （two-end jacking） to the middle of the strands or to the dead ends （one-end jacking）. The loading among the steel wires of the same one strand is not uniform and the differences of the loading are great. To achieve the relatively great effective stress, it is preferable to jack the strands at both ends and to use the plastic corrugated ducts.

关 键 词：长跨桥 连续刚构 预应力束 沿程应力 模型试验 

分 类 号：TU757.14[建筑科学—建筑技术科学]