连续刚构拱组合桥锚固区局部应力模型试验

Model Test for Local Stress Distribution in Anchorage Zones of Continuous Rigid Frame Composite Arch Bridge

为探讨连续刚构拱组合桥锚固区的局部应力,以宜万铁路宜昌长江大桥——连续刚构-钢管混凝土柔性拱新型组合桥为工程背景,分别进行了顶、底板模型试验,并与数值计算进行了比较,获得了锚固区局部应力的传递规律.此外,讨论了锚固区裂缝产生的原因.研究结果表明:在纵向预应力张拉过程中,箱梁锚固区始终处于弹性工作状态,锚垫板下混凝土受力是安全的;模型各测试截面混凝土测点应力与施加的荷载呈线性关系,结构处于弹性受力状态.

In order to investigate the distribution of local stresses in the anchorage zones of a continuous rigid frame composite arch bridge,model tests for roof and floor anchorage zones were carried out by taking Yichang Yangtze River bridge along Yichang-Wanzhou railway line as the research object,and the experimental results were compared numerical calculation ones.The transfer regularity of local stresses in the anchorage zones was obtained,and causes resulting in cracking in the anchorage zones were analyzed.The research results show that in the whole process of longitudinal prestressing tension,the box girder anchorage zones are in an elastic state,and stresses in concrete in testing sections have a linear relationship with applied load to indicate that the bridge structure is in an elastic state.