多跨斜拉-自锚式悬索组合体系桥全桥静力模型试验

Static model test of multi-span cable-stayed and self-anchored suspension composite bridge

为了验证多跨斜拉自锚式悬索协作体系桥梁结构的力学特性,以汉中西二环龙岗大桥为原型,依据静力相似理论,设计制作了1/20的全桥缩尺模型,重点研究了桥塔、主梁、拉索、吊杆的材料及截面设计原则,分析了它们在制造过程中的工艺难点及解决方法,制定了该类桥梁静力试验工况。结果表明:对弯压性质的模型试验,应采用截面的抗弯刚度和抗压刚度相似作为设计原则,受缩尺效应的影响,在试验前应全面考虑各材料选取、传感器的尺寸及位置等;成果可供以后类似工程模型试验提供借鉴;试验实测值与实桥换算的理论值吻合较好,模型桥反映的实桥受力特性良好。

In order to validate the mechanical properties of multi-span cable-stayed and self-anchored suspension composite bridge.Longgang bridge at Hanzhong west 2nd ring was taken as a prototype.According to the similarity theory of static test,1/20 scale-down model of the full-bridge was laid out.The material selection and section design principle for the tower,girder,cable and suspender were particularly studied,and the construction difficulty and its solution during the model manufacturing period were discussed,then the load cases of this kind of bridge static test were analyzed.The results show that using the section flexural rigidity and axial compressive rigidity similarity as the main design principles is appropriate for this kind of bridge for bending and compressive mechanical property.Selection of all materials,sensor size and position should be considered before the lay-out of the model owing to the scale-down effect.The study provides a basis for the similar project model test in the future.Theoretical value of model bridge agrees with the experimental date very well and the mechanical characteristics of real bridge have been reflected well by the model test.