列車行經高架軌道系統引致大地振動分析

Analysis of Ground Vibration Induced by Moving Trains on Viaduct

洪振發(Chen-Far Hung) ； 許維倫(Wei-Lun Hsu)

《中華民國振動與噪音工程學會論文集》 2015 (2015/06) Pp. 328-336

摘要

軌道系統由於其路線固定、準點、舒適等原因成為普及之大眾運輸工具，但由於軌道系統列車車輪軸距及行經路線固定等原因，易對鄰近環境持續造成振動之負面影響，尤其以大眾捷運系統，常緊鄰建築，因此在軌道系統在興建前必須對行經路徑周圍進行評估，並針對敏感路段進行精確的振動分析。臺灣目前評估新建之軌道系統造成之振動多依據美國運輸部FTA報告。而該報告之評估方式多根據經驗法則與簡化公式進行，對於鄰近民房、高科技廠房等建物之軌道系統，尚未能準確預估其引致之振動量及頻譜。本文以3D有限元素方法對列車以不同車速通過高架橋梁所引致鄰近大地環境振動進行探討，首先以過去文獻之分析結果比較LS-DYNA計算大地振動之分析結果，並考慮大地模型與橋梁結構模型分析不同車速通過引致大地振動傳播狀況，就車橋共振速度、車速、大地參數、基礎結構形式等影響進行探討，最後提出地表振動量與車速及距離之關係圖，並就大地振動反應頻譜進行檢討。

關鍵字

有限元素法 ； 大地振動 ； 軌道橋梁 ； 車橋共振

並列摘要

Railway became a popular transport system due to its specific route, scheduled time and riding comfort etc. The railway system has constant axle distance, and heavier axle load than the highway system. While the t rain passing by, the ground vibration propagated from viaduct is easily to induce low-frequency vibration and impact the neighbor buildings continuously. Prediction of its impact on environment is necessary before it constructed. Prediction of ground vibration induced by moving trains can follow guide of FTA report. The predict ion method proposed by FTA is based on statistics data and empirical method, and can't accurately analyze vibration spectrum and ground vibration propagation when the train is passing by. In this paper the 3D FEM is used to calculate the ground vibration induced by moving trains. Effects of different type of bridges foundation, ground characteristics, train speed and train-bridge resonant conditions on the ground vibration were examined. Finally, the distribution of ground vibration level versus train speed, distance form pier has been summarized.

並列關鍵字

FEM ； Ground vibration ； Viaduc Train-Bridge Interaction