含加勁材單柱式圓形鋼橋墩之耐震行為

Abstract

橋墩在橋梁系統作為主要發揮消能的韌性構件，能夠降低地震力造成橋梁整體結構的影響。因此，確保橋墩在設計地震力下有足夠的強度與韌性並且能夠立即進行修復極為重要。然檢視我國橋梁耐震設計規範，發現我國對於鋼橋墩斷面之細部設計著墨甚少，未有明確訂定標準，且各國耐震規範對於韌性的限制與背後之精神各有不同，故須經詳實之探討方可引用、參考至我國規範中。 為建立符合我國耐震規範韌性目標之細部設計標準，本研究主要針對含縱向加勁材之單柱式圓形鋼橋墩，探討其徑厚比、細長比、軸壓比以及縱向加勁材配置等參數對於耐震性能的影響。透過有限元素模型進行擬靜態的反覆載重分析以求取鋼橋墩的韌性容量值，再經由迴歸分析對含縱向加勁材單柱式圓形鋼橋墩提出耐震設計建議 。

Bridge piers function as the primary ductile components within a bridge system, playing a critical role in energy dissipation and thereby mitigating the impact of earthquakes on the overall bridge structure. Consequently, ensuring that bridge piers possess sufficient strength and ductility under design-level earthquake, as well as the ability to be promptly repaired, is very important. However, a review of Taiwan’s seismic design specifications for bridges reveals a lack of detailed provisions regarding cross-sectional detailing, with no clearly defined standards currently established. Furthermore, seismic codes across different countries adopt varying ductility requirements and underlying design philosophies, making it necessary to conduct detailed investigations before such standards can be referenced or incorporated into Taiwan’s design codes. To establish a detailing standard that aligns with Taiwan’s ductility requirements, this study focuses on single-column circular hollow steel piers with longitudinal stiffeners. The research investigates the effects of parameters such as diameter-to-thickness ratio, slenderness ratio, axial load ratio, and stiffener configuration on the seismic performance of the piers. Pseudo-static cyclic loading analyses are conducted using finite element models to evaluate the ductility capacity of the steel piers. Based on regression analysis, seismic design recommendations for the sectional properties of single-column circular hollow steel piers with longitudinal stiffeners are proposed.