本文以台北大直斜張橋為例,應用有限元素法進行結構靜、動態分析比較,探討地震力作用下台北大直斜張橋結構體之動態反應。藉電子計算機模擬分析,了解並掌握大直斜張橋結構動態行為特性。文中選用921集集大地震編號TCU068石岡國小測站地表加速度歷時記錄資料為地震荷載,考慮不同方向之地震力作用。分析時考慮非線性樑柱效應及纜索中垂效應之影響,並與線性分析結果進行比較。首先進行大直斜張橋結構初形分析找出其合理之初形位置及預力分佈,再以此初形分析結果進行變形分析、頻率分析以及地震分析,探討大直斜張橋之結構行為反應。
A finite element computation procedure for static and dynamic analysis of Taipei Ta-Chi cable-stayed bridge under the action of seismic loads is presented in the study. In the analysis the nonlinearities of cable sag effect and beam-column effect are taken into consideration. The initial shape of Taipei Ta-Chi cable-stayed bridge is first determined by iteration procedure. Based on the determined initial shape the static deflection of the bridge under traffic loads are determined, then the natural frequencies, vibration modes and dynamic responses induced by seismic loads are examined.