基于子模型法的独塔斜拉桥索塔局部受力分析

抚州赣东大桥主桥为独塔双索面异型结构斜拉桥,斜拉桥索塔交汇处的锚固区部位受力非常复杂。为掌握双索面独塔斜拉桥结构复杂区域的受力情况,本文首先采用MIDAS Civil软件建立桥梁的整体有限元模型,计算桥梁在不同荷载工况下桥塔的受力状态,然后选取索塔受力最不利的工况,应用子模型法,建立索塔的精细化有限元模型,对索塔的各个组成部分进行详细的受力分析。分析结果表明:索塔交汇处的锚固区部位总体满足受力要求,但局部应力集中现象比较严重,设计中应引起重视,建议通过适当的增加配筋解决应力集中现象,确保局部构造设计安全合理。索塔局部受力分析结果为设计和施工提供了依据,对同类桥型的设计具有一定的参考意义。

Local Stress Analysis on Cable Tower of Single Tower and Double Cable Plane Cable-stayed Bridge Based on Submodel Method

The main bridge of the Gandong Bridge in Fuzhou is a irregular shaped cable-stayed bridge with a single pylon and double cable planes. The stress of interchanges of pylons of anchorage zone of the cable-stayed bridge is rather complicated. In order to investigate the mechanical characteristics of the complex structure area for single tower and double cable plane cable-stayed bridge, full scale structural model is simulated by MIDAS Civil software. After analyzed different load states, the most unfavorable stress state is selected. Submodeling method is used to refined finite element model of the bridge tower, and different parts of bridge tower are analyzed. The results indicate that the interchanges of pylons of anchorage zone can generally meet the stress requirement but the stress concentration is relatively severe and special attention is suggested to pay to design. Some reinforcement should be added at the area of stress concentration and make sure the local structure design is safe and rational. The results can be referenced to design and construction, which would have significance for design reference of similar bridge in a certain degree.