以移動車輛所造成橋梁反應進行橋梁損傷評估之初步研究

Using bridge responses under moving truck loading to evaluate the damage of bridges a preliminary study

林協諭(Sie-Yu Lin)

指導教授 ： 鄭家齊

朝陽科技大學/理工學院/營建工程系/碩士(2013年)

摘要

近年來公共工程建設已經逐漸老舊，因新建成本之考量，對於結構之損傷檢測與評估成為國內外工程研究發展中最重視的議題，本文欲以重車行經有缺陷或無缺陷橋梁所得到動態位移，來分析橋梁勁度分布狀況，並進一步對橋梁損傷進行評估，為了解此試驗及分析方法之可行性，研究分為兩部份，第一部分為數值模擬，第二部分為鋼梁模擬試驗來進行分析比較。
分析方法是將量測到的動態位移，由紀錄之時間與車速轉換成車行位置求取動態位移影響線，再使用視窗濾波法濾除高頻訊號求取擬靜態影響線，並作二次微分得到曲率，再由曲率和力施於位移量測點的彎矩關係求得橋梁勁度。
在數值分析方面，採用了頻率域連續解動力分析程式（1DC.FOR），來進行數值模擬之參數研究，參數包括缺陷位置、範圍及勁度損失。分析結果顯示由數值模擬歸納出缺陷最大勁度損失百分率以及缺陷附近EI值變異區寬度可反推出模型I值損失百分率。
試驗方面則是使用模擬橋的鋼梁(6 m)和模擬車子的鋼球(8 kg)行進鋼梁求得勁度分佈及損傷狀況之探討。初步結果顯示，當勁度值越靠近缺陷位置時，勁度值會明顯地降低。

關鍵字

勁度評估 ； 監測 ； 橋梁

並列摘要

In recent years, the damage detection and evaluation of aging infrastructures becomes an important topic for domestic and international engineering research due to the increasingly high cost of constructing new structures. In present study, we would like to explore the idea of using the dynamic displacement response of a bridge corresponding to a heavy truck passing a defective or a non-defective bridge to evaluate the stiffness distribution along the bridge and assess the damage of the bridge. The study is divided into two parts- numerical simulation and experiment.
Analysis method is as following: Measure the dynamic displacement at one position. Transfer time into position of the moving vehicle to obtain a dynamic displacement influence line. And then use Windows filtering to obtain quasi-static influence line. The curvature is as quadratic differential of the influence line. Finally the bridge stiffness can be obtained by dividing the moment diagram for point load applied to the displacement measurement position to the distributed curvature.
In the numerical study, the continuous solution program (1DC.FOR) which perform the dynamic analysis in the frequency-domain is used , for parametric study. The parameters include the position, range and stiffness loss of the defects. The defect stiffness and position can be back cacluated from the percentage of stiffness loss, and the width of the stiffness decreasing zone.
In the experiment, the bridge girder was simulated by the H-beam and the moving truck was simulated by the rolling of the steel ball. Preliminary results indicate that the stiffness near the damage zone decreased substantially.

並列關鍵字

Bridge ； Monitor ； Assess Stiffness

參考文獻

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