乌江特大桥索塔锚固区节段足尺模型试验参数的确定

摘要

本文以遵贵扩容高速公路乌江特大桥为依托,对斜拉桥索塔锚固区段进行了分析研究,综合考虑设计索力大小、斜拉索角度、索塔整体受力叠加效应等综合因素,按最不利原则确定截取的索塔锚固区节段.针对所截取节段分别向上、向下延伸一定距离,以保证结构应力受模拟边界条件影响较小,同时分别取不同节段高度同实桥模型一样施加预应力、斜拉索索力、重力三项荷载,将有限元计算结果与实桥的计算模型进行比较,找出开裂能力与实桥一致的模型节段高度.文章首先介绍了乌江特大桥上塔柱斜拉索锚固区整体分析时所取用的模型情况,用ANSYS有限元软件模拟了整体模型在设计索力下的工作性能,通过对计算结果的分析,确定模型在设计索力下产生最大应力的最不利节段位置,并且给出索塔锚固区足尺试验研究所需的最不利节段高度.%Relying on the Wujiang River Bridge of the highway between Zunyi and Guiyang, the cable tower anchorage zone of cable-stayed bridge were analyzed.Considering the design of cable force, cable angle and the overall stress superposition effects, the anchorage zone segment section was determined by the most adverse principle.The anchorage zone segment was respectively extended upward and downward for a certain distance to ensure that the structural stress is less affected by the simulated boundary conditions.At the same time,the anchorage zone segment with different heights was applied by the same loads of prestressing force, cable force and gravity as the real bridge model.The finite element calculation results were compared with the calculation model of the real bridge to find the same cracking ability as the real bridge section height.The finite element model of bridge upper pylon anchorage zone used in the overall analysis was firstly introduced.The working performance of the overall model under the design cable force was simulated by the ANSYS finite element software.Based on the analysis of calculation results, the most disadvantaged segment with the maximum stress under the design cable force was confirmed and the height of the most disadvantaged segment needed by the full-scale model test of anchorage zone was proposed.