橋梁功能性支承系統於斷層近域之耐震性能

SEISMIC PERFORMANCE OF BRIDGE WITH FUNCTIONAL BEARING SYSTEM SUBJECTED TO NEAR-FAULT EARTHQUAKE

劉光晏(Kuang-Yen Liu) ； 劉立偉(Li-Wei Liu) ； 黃登綱(Deng-Gang Huang) ； 呂依涵(Yi-Han Lu)

《中國土木水利工程學刊》 31卷5期 (2019/09) Pp. 443-454

https://doi.org/10.6652/JoCICHE.201909_31(5).0004

摘要

本研究採用狀態空間法，提出橋梁含功能性支承且考慮雙線性彈塑性橋柱之位移解析流程，希望透過提出的方法探討公路橋梁於近斷層地震作用下的反應，以了解支承摩擦與橋梁受力之間的交互關係。分析模式是將橋梁系統簡化為雙自由度系統，特點在於考慮橡膠支承墊於黏著與滑動狀態間、橋柱於彈性與塑性狀態間之非線性變化過程，並有效分離支承剪力變形量與滑動位移量，並與SAP2000模型作合理性之驗證。本研究主要針對橡膠支承墊摩擦係數、橋柱高度與最大地表加速度進行參數分析，分析結果主要探討橡膠支承墊最大位移、橡膠支承墊殘留位移、橋柱剪力、橋柱殘留位移、橋柱韌性需求與橋柱塑性轉角。分析結果顯示，橡膠支承墊摩擦係數對整體橋梁反應影響最大，當摩擦係數較低時，有支承墊滑動位移過大造成落橋的事件發生；當摩擦係數較高時，向下傳遞的摩擦力過大導致橋柱降伏，甚至面臨拆除或補強，也有超過公路橋梁耐震設計規範所規定韌性容量值的案例發生。本研究成果可提供公路橋梁耐震設計規範修訂活動端支承與橋柱之參考依據，檢討防落長度、橋柱設計剪力與橋柱韌性需求值等。

關鍵字

功能性支承系統 ； 雙線性彈塑性 ； 開關系統 ； 近斷層地震

並列摘要

In this study, a state-space based analytical method is presented to predict the displacement demand for a bridge with functional bearing system and bilinear elastoplastic pier. A simplified two degree-of-freedom system was adopted to account for the sticking and sliding states of the rubber bearing, and the elastic and plastic states of the pier, and effectively separate the shear deformation and sliding displacement. The accuracy and rationality of this method were successfully verified by SAP2000. Three major parameters including the friction coefficient of rubber bearing, the height of pier and the peak ground acceleration are selected for parameter study to investigate the seismic performance of the bridge under near-fault earthquakes. In the future, demand of both unseating length and shear force of pier could be further investigated by the result of this parameter study.

並列關鍵字

functional bearing system ； bilinear elastoplastic ； on-off switching mechanism ； near-fault earthquake