跨越池上斷層之玉里大橋長期潛動分析研究

A STUDY ON THE LONG-TERM CREEP AND DISPLACEMENT CHARACTERISTICS OF THE YU-LI BRIDGE CROSSING CHIHSHANG FAULT

蘇進國(Chin-Kuo Su) ； 林宏軒(Hong-Syuan Lin) ； 宋裕祺(Yu-Chi Sung) ； 洪曉慧(Hsiao-Hui Hung) ； 趙國宏(Kuo-Hung Chao) ； 鄧文廣(Wen-Kuang Teng) ； 陳松堂(Sung-Tang Chen) ； 楊秉順(Ping-Shun Yang)

《中國土木水利工程學刊》 32卷1期 (2020/03) Pp. 101-115

https://doi.org/10.6652/JoCICHE.202003_32(1).0009

摘要

對於橋址座落鄰近斷層或跨越斷層之橋梁結構，主要的地震影響可歸納成瞬時反應及地表長期潛動位移等二類，前者以短時間釋放能量及速度脈衝為特徵，後者則以長時間地表緩慢變形為主，惟斷層發生相對錯動時，兩者均將造成橋梁上、下部結構間相對位移及結構體損傷等情形。為有效掌握跨越斷層或近斷層橋梁特性，本文以台9線玉里大橋為例，採用大地強制變位分析法，研析池上斷層長期潛動下的橋梁結構變形現況，並與長期量測資料進行比對，據此探討橋梁結構安全性及推估後續長期潛動發展趨勢。研究成果冀能對於學術研究或工程實務提供實質助益。

關鍵字

跨越斷層橋梁 ； 地表潛動位移 ； 土壤結構互制 ； 有限元素分析

並列摘要

For bridges that are near-fault or crossing-fault, the ground motion that causes hazards can be categorized into short-term transient displacement and long-term creep displacement. The hazard cause by former can be characterized by accumulated energy dissipation in a short time and a conspicuous velocity-impulse behavior, and the latter can be distinguished for gradual deformation of structure due to long-term creep. However, both could induce adverse relative displacement between superstructure and substructure, and the structural members could damage or even progressive collapse while the displacement demand is less than the design capacity. In this paper, a case study of the Yu-Li Bridge was conducted to investigate the effect of long-term creep on the seismic behavior of bridges. A three-dimensional finite element model that incorporates both the whole bridge and the surrounding soil was established to take the soil-structure interaction effect into account directly. Using this model, nonlinear static analyses were performed to obtain the seismic responses of the bridge due to incremental displacement of the Chihshang fault. By a meaningful comparison with historic measured data, the seismic response and future development of the bridge associated with ground motion are both discussed. It is expected that the research results could provide useful and practical perception to those who are interested in the domains of near-fault or cross-fault ground research.

並列關鍵字

crossing-fault bridges ； creep ground displacement ； soil-structure interaction ； finite element analysis