南京长江第四大桥节段预制拼装箱梁足尺模型试验  

Full-Scale Model Test for Precast and Assembled Segmental Box Girder of the Fourth Nanjing Changjiang River Bridge

作　　者：刘钊[1] 武焕陵[2] 种艾秀 聂永福[1] 惠卓[1] 王景全[1] 

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]南京长江第四大桥建设协调指挥部,江苏南京210033 [3]中交二航局四公司,安徽芜湖241006

出　　处：《桥梁建设》2011年第3期9-12,16,共5页Bridge Construction

基　　金：江苏省交通科学研究计划(09Y11)

摘　　要：为研究节段预制拼装箱梁在正常使用阶段和施工状态下的结构行为,结合南京长江第四大桥开展了一孔48 m跨径该类箱梁的足尺模型试验。首先模拟正常使用荷载工况,测试试验梁的主要静力反应,然后模拟在张拉一部分预应力束的梁上通行运梁车的工况,测试试验梁的应力状况,并采用ANSYS建立试验梁实体有限元模型进行对比分析。研究结果表明:在正常使用阶段,节段预制拼装桥梁的整体性较好,键齿接缝两侧基本没有相对滑移,加载、卸载后梁体残余变形较小,力学行为基本符合平截面假定;在梁上运梁工况下,实测梁体下缘压应力约为6 MPa,距消压状态还有一定的安全储备。To investigate the structural behavior of precast and assembled segmental box girders at regular service stage and in construction state,the full-scale model test for a span of 48 m box girder of such type of the Fourth Nanjing Changjiang River Bridge was made.Firstly,the regular service load cases were modeled and the main static responses of the tested girder were measured,then the load cases of traveling of the girder segment transportation trailer on that girder with part of its prestressing strands being tensioned were modeled and the stress conditions of the girder were measured and finally the ANSYS was used to set up the solid finite element model to compare and analyze the girder that was tested under the said two types of the load cases.The results of the investigation demonstrate that at the regular service stage,the global performance of the girder is good,the part of the girder at a studding tooth joint almost has no relative slip,the residual deformation of the girder after loading and unloading is little and the mechanical behavior basically accords with the hypothesis of plane section.Under the load cases that the girder segments are transported on the girder,the measured compression stress in the lower flange of the girder is round about 6 MPa,which exhibits a certain safety margin as from the decompression state.

关 键 词：预应力混凝土桥 节段预制 拼装 体外预应力 模型试验 有限元法 

分 类 号：U448.38[建筑科学—桥梁与隧道工程]