鹅公岩轨道专用桥主缆锚固区模型试验研究

Model Test Study of Main Cable Anchorage Zone of Egongyan Rail Transit Special Use Bridge

重庆鹅公岩轨道专用桥为主跨600m的自锚式悬索桥,为研究其主缆锚固区的受力性能与传力规律,设计制作缩尺比1∶5的主缆锚固区节段模型进行静力试验,测试模型的应力与压缩变形,并将试验结果与有限元分析结果进行对比。结果表明:设计荷载作用下,主缆锚固区未出现开裂;加载至2.0倍设计荷载时,模型出现2条裂缝,裂缝最大宽度为0.15mm;试验加载过程中,主缆锚固区各构件的纵向应力随荷载增大均线性增大,结构处于弹性工作阶段;各构件纵向正应力由锚固横梁向结合段横梁纵向变化规律总体表现为先增大后减小;2.0倍设计荷载作用下,锚固区各构件压应力均小于混凝土抗压强度标准值,结构具有足够的安全储备。

Egongyan Rail Transit Special Use Bridge in Chongqing is a self-anchored suspension bridge with the main span of 600 m.In order to study the mechanical behavior and force transmission law of the main cable anchorage zone of the bridge,the sectional model for the main cable anchorage zone on the scale of 1∶5 was designed and prepared,and the static test for the model was carried out.The stress and compression deformation of the model were measured in the test,and the test results were compared with the ones of the finite element analysis.The results reveal that no cracks occur in the main cable anchorage zone under the action of the design load.Two cracks occur in the sectional model when 2.0 times of the design load is loaded and the maximum width of the cracks reaches 0.15 mm.The longitudinal stress of each component in the main cable anchorage zone increases linearly with the load during the loading process of the test,and the structure still stays at the elastic stage.The overall performance of the variation law of the longitudinal normal stress from the anchorage cross beam to the cross beam in the joint section of the model is that the stress of each component increases first and then decreases.Under the action of 2.0 times of the design load,the compression stress of each component in the anchorage zone of the model is less than the standard value of the concrete compressive strength,and the structure has sufficient safety margin.