工程力学论文

石家庄铁道学院毕业论文

单斜塔斜拉桥主塔提升受力分析

Analysis of Main Tower of Cable-stayed

Bridge with Single Skew Tower during its

Hoisting Process

届系工程力学

专业工程力学

摘要

本文以天津市泰达天桥——单斜塔斜拉桥为背景，研究单斜塔斜拉桥主塔提升的受力情况。整个课题的研究过程采用了有限元的分析方法，利用工程分析软件ANSYS 进行建模求解。

首先根据设计图纸建立该桥完整的初始空间有限元模型，并根据设计内容的要求施加自重和相应的风荷载，然后求解并对提升系统在提升到不同角度时的反力、位移和应力等进行理论分析以确保主塔提升过程的安全可靠。根据受力情况塔架采用了Link8和Beam4两种单元，主塔采用了Shell63单元，索采用了Link10单元。计算结果表明单元的选取都是合理的；应力的最值出现在提升索和主塔的连接处，存在应力集中的现象，在排除了局部应力集中的情况下，整个提升过程安全可靠，因此，在施工过程中对局部应力集中处采取有效的加固措施显得至关重要；结果分析显示提升索力的变化是非线性的，提升起始阶段的索力较大，随后索力不断减小，接近提升终止时，提升索力又变大。提升索的最大索力为2150kN，出现在提升的终止阶段；变形最大的点一般出现在吊梁的中点附近，但并未超出允许值。

关键词：单斜塔斜拉桥有限元分析提升过程

Abstract

Tianjin Taida flyover, a single skew tower cable-stayed bridge is used as the background in this paper. The stress of the main tower of cable-stayed bridge with single skew tower during its hoisting process is researched here. The whole design process uses the finite element method and uses ANSYS, an engineering analysis software, to mode and solve.

The initial space finite element model of the bridge is established firstly, according to its drawings. At the same time, the dead weight of the bridge and the corresponding wind loads are also imposed on the bridge according to the design requirements. Then reaction force, displacement and stress are analyzed when the system is enhanced to different angles in order to ensure the safety and reliability of the main tower during its whole hoisting process. The tower frame uses two elements, Link8 and Beam4, according to the force conditions. The main tower uses the Shell63 element and the cables use the Link10 element. The results prove that the selections of these elements are reasonable. The biggest value of the stress is at the connection of the main tower and the lifting-cable, where exists the phenomenon of stress concentration. The hoisting process is safe and reliable when the local stress concentration is eliminated. So it is very important to strengthen the positions of the local stress concentration during the construction process. The change of the lifting-cable tension is nonlinear showed by the results. The value is larger at the beginning of the lifting process and it decreases during the process. The value of the lifting-cable tension turns larger again when the whole process is close to the end. The biggest value is 2150 kN and it happens at the end of the process. The point which happens the greatest deformation is always at the midpoint of the hanging beam and it does not exceed the allowable value.

Key words: Single Skew Tower Cable-Stayed Bridge Finite Element Analysis Hoisting Process