大跨度矮塔斜拉桥V形钢主塔的竖转施工与结构分析

Analysis on Vertical Turning Construction and Structure of Main V-shaped Steel Pylon of Long-span Short-pylon Cable-stayed Bridge

由于机场航空限高60 m的要求,宁波中兴大桥主桥采用了大跨度矮塔斜拉桥的设计方案,其V形钢主塔施工采用桥面上拼装然后竖转成型的施工方法。钢主塔竖转施工是主桥施工的一个重点与难点,着重介绍了钢主塔的吊装节段划分与竖转施工的主要步骤。根据施工步骤进行了主塔竖转过程的结构整体分析,得到了钢主塔及临时结构的整体受力特性。为进一步验证钢主塔竖转过程结构的安全性,对关键节点-竖转上转餃、下转铉以及上对拉较进行了有限元仿真分析,得到了关键节点的局部应力与变形。结构的整体与局部分析结果有效验证了钢主塔竖转过程中结构的强度与刚度能够满足相关规范的要求。

Due to the aviation limit of 60 m at airport,the main bridge of Zhongxing Bridge in Ningbo adopts the design scheme of long-span short-pylon cable-stayed bridge.Its V-shaped steel pylon is constructed by the method of assembly at bridge deck and then vertical turning to forming.The vertical turning construction of main steel pylon is a key point and difficulty in the construction of main bridge.This paper specially introduces the division of hoisting segments and the main steps of vertical turning construction of the main steel pylon.Based on the construction steps,the whole structure of main pylon vertical turning process is analyzed.The whole mechanical characteristics of main steel pylon and temporary structures are obtained.In order to further verify the safety of structure in the vertical turning process of the main steel pylon,the key nodes of vertical turning the upper hinges and lower hinges as well as upper butt hinges are carried out of finite element simulation analysis to know the local stress and deformation of the key nodes.The whole analysis and local analysis of the structure efficiently verify that the strength and rigidity of the structures can satisfy the relative specifications and requirements in the vertical turning process of the main steel pylon.