长寿长江公路大桥索塔节段足尺模型试验研究

Full-scale Model Test for Pylon Segment of Changshou Yangtse River Highway Bridge

为研究小半径大吨位U形预应力钢束的孔道摩阻系数、钢束伸长值以及索塔锚固区的应力分布规律,以重庆长寿长江大桥索塔锚固区为研究对象,在理论分析的基础上进行了索塔锚固区节段的足尺模型试验。介绍了模型试验的内容、步骤、方法。通过测试分析得出了U形塑料波纹管孔道合理的摩阻系数和钢束伸长值。对索塔模型在U形预应力下以及斜拉索作用下的应力进行了量测与计算分析,指出了节段的应力分布规律,并将试验结果与有限元分析计算结果进行了比较,两者分布规律吻合较好,结果表明结构设计安全可靠。

In order to study the tunnel frictional resistance, the extension of tendons and the stress distribution of cable-pylon anchorage zones for U-type prestressed tendons with great tonnage and small radius, a full-scale pylon segment model including one whole anchorage of cable was tested based on theoretical analysis of Changshou Yangtse River Highway Bridge in Chongqing. The content, procedure and method of the test were introduced. The reasonable frictional coefficient values of the U-type plastic corrugated pipes and the extension values of tendons were provided by test analysis. The stress distribution in the model under the U-type prestress and stayed cable actions was measured and analyzed and the stress distribution regularity of the segment were pointed out. The stress distribution features of the pylon segment were pointed out. The result shows that the stress distribution between measured values and calculated values are basically identical and the structure is safe and reliable.