橋墩基礎裸露對橋梁結構振動反應之影響

A Study on the Influence of Pier Foundation Exposure on Structural Vibrational Response of Bridge

柯永彥(Yung-Yen Ko) ； 張為光(Wei-Kuang Chang) ； 陳正興(Cheng-Hsing Chen)

《中國土木水利工程學刊》 23卷1期 (2011/03) Pp. 103-110

https://doi.org/10.6652/JoCICHE.201103_23(1).0009

摘要

結構系統之振動反應能表現系統自身特性，並可反映邊界條件之變化，已廣泛應用於結構系統識別與損傷評估。本文首先利用數值分析，說明橋墩基礎裸露對基礎本身與橋梁上部結構振動反應之影響。另於台三線汶水橋進行現地振動量測，利用頻譜分析與易損指數，實際探討橋墩基礎裸露所造成橋梁上部結構振動特性之變化。並建立汶水橋振動單元模型進行模態分析與動態歷時分析，藉以驗證現地振動量測之結果。由研究成果顯示，量測橋梁上部結構振動反應確有助於評估橋墩基礎之裸露情況。

關鍵字

基礎裸露 ； 橋梁振動反應 ； 易損指數

並列摘要

The vibration of a structure system characterizes the system itself and also reflects the variation of the boundary conditions. Therefore, vibration measurement has been widely applied to the system identification and the damage evaluation of structures. In this study, the influence of pier foundation exposure on the vibrational response of the foundation itself and the bridge superstructure were first demonstrated by numerical analysis. Field vibration measurements were made at the Wensui Bridge of Provincial Highway No. 3 to actually investigate the variation of vibration characteristics of the bridge superstructures caused by foundation exposure using the spectral analysis and the vulnerability index. In addition, the bridge unit model of the Wensui Bridge was established to perform the modal analysis and the dynamic time history analysis for the verification of field measurements. All these results showed that the measurement of the vibration of the bridge superstructure can be used to estimate the exposure of the pier foundation.

並列關鍵字

foundation exposure ； vibration response of bridge ； vulnerability index