台鐵「軌枕埋入式軌道」振動特性研究

Abstract

本研究提出一套以商用軟體SAP2000為分析工具，利用空間移動之三角波時間函數為輸入擾動模擬單一及序列性等速移動荷重，並配合雙層離散黏彈性支承分析模型，以模擬軌道系統之動態反應。透過與文獻結果之比較，確認本文所提分析模式的合理性，將可應用於條件更複雜、得不到解析解的軌道系統動力分析問題。運用此一數值模擬方式，本研究針對台鐵防振型軌枕埋入式軌道(無道碴型式) 進行分析，分別探討在下部結構為隧道或橋樑等條件下，軌枕質量、鋼軌墊片勁度及軌枕間距等軌道系統參數對動態反應之影響。此外，本文亦就列車不同車速對於軌道系統造成之衝擊效應進行分析，以供實務參考。

A numerical scheme, using SAP2000 as the tool, for dynamic response analysis of railway track systems is proposed in this study by introducing move-in-space triangular wave functions as single or sequential constant moving loads, with a discrete double-layer viscous-elastic model for the bearings. Adequacy of the proposed scheme is confirmed by comparing the simulated results with those depicted in the literature, and thus allowing for dynamic analysis of railway track systems in more complex conditions where no analytical solution could be available. Based on the proposed numerical scheme, this study investigates the dynamic characteristics of the sleeper-embedded track (non-ballasted track) of TRA on either bridges or in tunnels. Effects of sleeper mass, rail pad stiffness & sleeper spacing on the dynamic responses have been explored. Moreover, the impact effects of the train moving speed is also investigated for practical concerns.