高屏溪斜張橋三維結構分析

3-Dimensional Nonlinear Analysis of Kao-Ping-Hsi Cable-Stayed Bridge

吳崧琦(Sung-Chi Wu)

指導教授 ： 王寶璽

中原大學/工學院/土木工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400468

摘要

摘 要

本文應用有限元素法進行斜張橋三維靜、動態分析比較，探討其線性與非線性變形反應、振動特性，及地震力作用下結構體線性與非線性動態結構行為。分析時考慮非線性樑柱效應、幾何大變位效應及纜索中垂效應之影響，並與線性分析結果進行比較。文中以高屏溪斜張橋為例，建立三維分析模型，首先進行初形分析，以求得合理的初形及預力分佈。而後並就此初形位置進行活載重在不同配置下之變形分析及振態、頻率分析，瞭解結構體的基本靜、動力特性，最後應用Newmark- 法進行強震作用下斜張橋結構體之線性與非線性動態反應。地震荷載之選擇為含強近地動特性之集集地震（TCU068測站），分別就不同地震輸入方向組合作用，期能找出最不利該斜張橋之地震輸入方向，並確實掌握該橋體在強震作用下之結構行為，並比較線性與非線性反應之結果。數值分析結果顯示，在靜態交通荷載作用下，主要變形發生在橋樑大樑之垂直向，而在單向車道滿載作用下亦顯現扭轉變形效應，低頻振態以橋面垂直向振動為主。當三主方向分別受文中所選用地震力作用時，高屏溪斜張橋主要受水平順橋向地震力控制，且非線性效應及垂直地震力之效應在斜張橋結構分析中不容忽視。

關鍵字

斜張橋 ； 近地動 ； 地震動力分析 ； 扭轉變形

並列摘要

Abstract

A finite element computation procedure for linear and non-linear static and dynamic analysis of three-dimension long-span cable-stayed bridge under action of live loads and seismic loads is presented in the study. The system equation of cable-stayed bridges including the nonlinearities due to large displacement, beam-column and cable sag effects is first set up and compared with the results of the linear computation procedure. the Kao-Ping-Hsi cable-stayed bridge in Kao-hsiung, Taiwan is taken as example. First of all, the initial shape of cabled-stayed bridge is determined by using shape iteration technique. Based on the initial shape the linear static deflection, natural frequencies and modes, linearized and nonlinear dynamic responses seismic action are determined. In order to examine the behavior of the cable-stayed bridge under strong seismic excitation, five different combinations of seismic excitation are applied in this paper. It is shown in the numerical results that this bridge is mainly controlled by the horizontal X seismic excitation along the direction of girder axis. The results also show that geometric nonlinear effects and vertical seismic excitation have to be considered in the seismic analysis of cable-stayed bridge.

並列關鍵字

near-fault ； nonlinear dynamic analysis ； cable-stayed bridge

參考文獻

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