摘要 本研究以具坡度橋面橋梁之碰撞效應為研究目標。過去多次因碰撞造成橋梁震害，橋梁碰撞效應已有許多研究成果提出，然而過去研究的目標橋梁多是以等高橋墩下之水平橋梁為主，並未有具坡度橋梁之相關案例分析。實際上，諸如高架橋匝道、高架道路跨越橋、山區地形變化處之橋梁，橋面坡度變化較大，更甚可達10%。 坡度效應對於橋梁碰撞現象、破壞形式及結構動力反應之影響，目前仍未有文獻研究此課題。因此本研究建立具坡度橋面橋梁數值模型，藉由變更橋墩高度，調整橋面坡度，進行參數分析研究。並設計小型具坡度橋面鋼橋模型，進行小型振動台試驗，並建立數值分析模型，數值分析結果並與實驗結果相較，確認用以模擬碰撞之數值模型之準確性。 最後本研究以一座依日本道路橋示方書設計之隔震橋梁為目標橋梁，變化橋墩高度調整橋面坡度，建立該橋數值分析模型，詳細探討坡度變化對隔震橋梁破壞效應之影響，以及橋梁各構件動力行為之影響。研究結果顯示，橋面版坡度越大，兩相鄰橋面版間之相對變位愈大，碰撞次數與碰撞力愈高，支承最大剪力變形、橋墩最大旋轉角以及支承軸力亦增大，甚至產生相當大之拉拔力，顯示坡度對於大地震中橋梁之動力反應影響甚大，建議較大坡度之橋梁設計時應將坡度效應納入考量。 ABSTRACT Through the experience of past extreme earthquakes which caused extensive damage, a number of bridges suffered damage so as to hamper the rescue even the recovery of economy. In these events, pounding between decks was observed on most of the bridges which suffered severe damage even unseating. Although the pounding effect of seismically-excited bridges has been studied by many researchers, the bridges with inclined decks have not been investigated on this effect. However, the decks of bridges should be of slopes due to various terrain, route alignment and elevation. Occasionally the slope is up to 10%. Therefore, this research is aimed to study the pounding effect of bridges with inclined decks under strong ground motions. Then, to clarify the accuracy of the analytical model of inclined bridges with pounding, a series of shaking table tests are conducted by using a small steel model under harmonic excitations. Through comparison, the analytical results agree to the experimental results very well. Finally, we analyze an isolated bridge to investigate the extreme effects of the slope for bridges, bearings and columns and to discuss the damage and dynamic responses of target bridges. The numerical results indicate that the relatively displacements, the pounding number and forces, bearing forces increase as the slope of decks increases, In particular, large slope causes the isolators to exhibit tensile forces, which is harmful to the bridges.
