本文探討捷運高架橋系統在行駛列車衝擊高架橋產生的振動問題,分析軌道系統在使用隔振基鈑與浮動式道床後對高架橋橋體產生的振動差異,先討論在使用不同基鈑狀況下車-軌-橋各系統振動耦合頻率的改變,以完整FEM模型模態分析所得各結構子系統的自然頻率為依據,建立車-軌-橋簡化離散模型,再利用Ansys有限元素分析軟體對車-軌-橋簡化離散模型進行諧和振動分析,討論在使用不同基鈑的情況下的振動量與入力量,並檢討採用高隔振基鈑的頻域資料的插入損失的比較。最後建立完整FEM模型以LS-DYNA有限元素分析軟體進行列車行經高架橋,衝擊軌道引致振動之暫態分析,檢核高隔振基鈑與浮動式道床兩種減振措施對列車車體、高架橋結構與大地入力的影響,及其頻譜插入損失,討論高隔振基鈑與浮動式道床減振的有效頻率範圍,及對列車振動的影響。
The paper investigated the vibration problems of viaduct-rail system induced by moving trains.The mitigation of viaduct vibration by using Non-ballast hight insulation track(NBHI) or Floating Slab Track(FST) were compared.First of all,the FE modal analysisof train-track-viaduct system was performed discrete model of train-track-viaduct system was established based on the result of FE-modal analysis.Second,the harmonic analysis for the discrete model by Ansys was carried out the reduction of input force on track system by using Non-ballast hight insulation track(NBHI) was discussed.Finally,we performed the finite element the transient analysis by LS-DYNA to simulate the impact on track system induced by moving train.The train vibration,viaduct vibration,and input groundforce were analyzed, insertion loss of vibration by NBHI and FST were exammined.