探討多排管樁對高速列車所產生地表振動之減振效果

The isolation effectiveness of multi-row pipe pile barriers for high speed train induced vibration

何佳欣(Jia-Xin He)

指導教授 ： 蔡佩勳

朝陽科技大學/理工學院/營建工程系/碩士(2016年)

摘要

現今都市發展迅速，現代人對於交通運輸工具的要求也隨之提升，為了滿足快速、便捷等需求，發展出的高速鐵路及捷運列車等，更是造福許多人。當這些大眾運輸列車行經於都會區時，所引發之振動會影響到附近居民生活品質，因此，如何有效降低列車所引發之振動是值得被重視的。
本研究於現地進行多頻道表面波震測試驗，求得研究地點之土層剪力波速分布，並配合鑽探結果，建立剪力波速剖面。研究區域之地層以兩層土壤模擬，上層及下層土壤之剪力波速分別為200m/sec、300m/sec，此將用於後續有限元素模型之土層材料參數設定。於現地進行高鐵列車產生之振動量測，得知高鐵列車主要振動頻率約在0Hz~50Hz之間。將現地量測之振動資料與數值模擬結果進行比對，發現兩者在0Hz~50Hz間皆有良好的吻合性，確認本研究後續建立設埋多排管樁之有限元素分析模式合理性。
利用有限元素軟體ABAQUS來模擬當高速列車行經時，列車對地表面所產生之振動情況，探討土壤埋設多排管樁後之減振效果。於三維模型上設置3排管樁，在垂直鐵軌方向設置3條測線，取得測線上各測點之速度歷時曲線，再以Matlab軟體進行傅立葉轉換與1/3八音階頻帶分析，得到地表速度均方根減少量，繪製減振效率圖，用以評估多排管樁之減振效益。由結果顯示，在本研究的參數範圍下，比較埋設多排管樁之前後的地表振動反應，發現皆有降低地表振動的效果，尤其是對於降低5 Hz ~25Hz的振動，約可降低34dB。在第二排管樁之後方，即有明顯之減振效果。平行鐵軌方向之排樁中心間距越小，越能達較好之減振效果，而垂直於鐵軌方向之排樁間距越大，減振效果越佳。

關鍵字

高速列車 ； 減振效果 ； 1/3八音階頻帶分析 ； 多排管樁

並列摘要

The transportation requirements increase because that economy and society develop rapidly. In order to transport the passengers and cargo rapidly, high-speed train has been used. When the trains pass the metro area, the vibrations induced by the trains will affect the living quality of nearby people. Therefore, how to reduce effectively the vibrations induced by the trains is worthy of attention.
In this study, a multi-channel surface wave seismic test was performed to obtain soil shear wave-velocity profile in the study site. From the results of the surface wave seismic test and drilling data, the profile of shear wave velocity in study site will be established. A two-layer soil was confirmed and it will be used to simulate the stratum of study site in the following numerical study. The shear wave velocities in upper and lower soil-layer are 200 and 300 m/s, respectively. These parameters will be used for the subsequent finite element numerical analysis. From the measured vibration on ground surface induced by high-speed train, it can be seen that the main vibration frequencies are between about 0-50 Hz. The measured vibration data were compared with those by numerical simulation, it can be found that the both results are close in the frequency range of 0-50Hz. Therefore, the procedures of numerical simulation are confirmed to be rational.
The finite element software ABAQUS was used to analyze the isolation effectiveness of three rows of pile on reducing ground surface vibration induced by high-speed trains. In the vertical direction of the track, three survey lines were set up and recorded the acceleration time history of the monitored points along the survey lines. Then, the vibration records will be performed Fourier transformation and 1/3 octave band analysis with Matlab software to obtain the reduction vibration distribution images of multi-rows of pile. The isolation effectiveness will be estimated from the reduction vibration figures or be calculated by the reduction of velocity level. From the results of parametric study, three rows of pile can effectively reduce vibration induced by high-speed trains. Especially for reducing vibration in the frequency range of 5-25 Hz, it can reduce about 34 dB. It is obvious that the ground vibration behind the second row pile can reduce effectively. The isolation effectiveness of piles increases due to the reduction of the spacing of piles in the parallel track direction. The spacing of piles in the direction perpendicular to the track is fewer, it will reduce more vibration.

並列關鍵字

isolation effectiveness ； 1/3 octave band analysis ； high-speed train ； multi-rows of pile

參考文獻

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