七塔预应力混凝土部分斜拉桥结构性能研究  

Study of Structural Behavior of 7-Pylon PC Extradosed Bridge

作　　者：何祖发[1] 李振 

机构地区：[1]中铁大桥局集团桥科院有限公司,湖北武汉430034 [2]盘锦市交通建设有限责任公司,辽宁盘锦124010

出　　处：《桥梁建设》2010年第6期44-48,共5页Bridge Construction

摘　　要：采用有限元法分析多塔预应力混凝土部分斜拉桥的结构性能。同斜拉桥一样,部分斜拉桥可以通过优化拉索初张力,确定其合理成桥状态,并通过优化施工方案,保证结构安全、受力合理。部分斜拉桥的拉索主要承担恒载,活载主要由主梁承担;活载作用下斜拉索最大应力幅位于边跨最外侧的斜拉索,已接近斜拉桥拉索应力幅;塔顶水平位移与相邻塔的变形相互影响较小。以大广高速公路开封黄河大桥为例,通过改变结构为连续梁桥和斜拉桥体系后,对比分析3种结构体系活载作用下的结构性能,得知:从连续梁桥、部分斜拉桥到斜拉桥,结构体系整体刚度逐渐增大,主梁承受的弯矩逐渐减小、结构变位逐渐减小、结构各阶自振频率逐渐增大。The finite element method is used to analyze the structural behavior of the multipylon prestressed concrete （PC） extradosed bridge. Like a cable-stayed bridge, the rational completion status of the extradosed bridge can be determined through optimizing the initial tensioning force of stay cables and the safety and rational force conditions of the structure can be ensured through optimizing the construction schemes. The dead load of the extradosed bridge is mainly carried by the stay cables while the live load is carried by the main girder. The maximum stress amplitude of the stay cables under the action of live load is at the outmost cables at side span, which is quite close to that of the stay cables of the cable-stayed bridge and the mutual influence between the horizontal displacement at the top of a pylon and the deformation of the adjacent pylons is little. By way of example of Kaifeng Huanghe River Bridge on Daqing-Guangzhou Expressway and by changing the structure into the continuous girder and cable-stayed bridge, the structural behavior of three types of the structural systems under the action of live load is comparatively analyzed. It is known from the analysis that from the continuous girder to the extradosed bridge to cable-stayed bridge, the global rigidity of the structure gradually increases, the bending moment carried by the main girder and the structural displacement gradually decrease while various orders of the natural vibration frequency of the structure gradually increase.

关 键 词：预应力混凝土结构 部分斜拉桥 合理成桥状态 结构性能 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]