高速列車行經過渡段軌道結構之動態反應

Abstract

台灣的島嶼呈現狹長的形狀，台灣高鐵路線貫穿西半部地區。沿線地形起伏多變，為了因應地形變化，軌道結構型態以高架為主，部分為路工路段以及隧道路段。在路面基礎鋪設軌道之路段稱為路工段。在高架橋與路工段的交界處由於軌道結構類型及軌道基礎特性改變，稱為過渡路段。同樣的，在路工段與隧道口的交界處也是一個過渡路段。當列車通過過渡路段時由於軌道結構型態與基礎勁度改變，將引起較大的動態反應為本文的研究重點。 本文研究重點在於藉由LS-DYNA有限元素分析軟體分析台灣高鐵隧道洞口處在10公尺內經過高架、路工與隧道三種路段之過渡段軌道結構在高速列車通過時，列車與軌道結構振動的動態反應。 本文先分析台灣高鐵700T型列車之車廂通過過渡路段時，在高架橋路段、路工段與隧道路段的軌道結構反應情形。從各檢核點的位移、速度、加速度之時間歷時圖對照列車行經之結構位置作討論。根據檢核點的各種動態反應，分別考慮當軌道在路工段與隧道段交界處有拱起，以及路工段的路盤混凝土底部與路基結構不完全接合之狀況。最後再探討當行經過渡路段時，列車本身起伏的振動反應。結果顯示兩種狀況對於軌道結構振動量皆有影響，交界處之拱起對於列車通過時引車體動態反應影響較顯著，路盤混凝土底部之不完全接合對於軌道結構振動影響較顯著。

Taiwan High Speed Rail passes through the west side of Taiwan. In other to match up varied elevation of landforms, most of the rail structure are layed on viaduct, some of them are layed on tunnel or on land. The track structure between two type sections is called a transitional section, e.g., tunnel and land, or land and bridge. This thesis focuses on the dynamic response of transitional section induce by high speed passing train. In this thesis, the transient dynamic finite element method code – LS-DYNA was used to analyze the dynamic response of track structure on different type of rail section induced by single moving carriage. First, we simulate single carriage passing the bridge-land transitional section and land-tunnel transitional section, and observe the displacement, velocity, acceleration response of check points on different position of rail structure. Base on the dynamic response, we discuss the effect by two conditions - uneven rail track, and imperfect connection between concrete bed of track and foundation. Finally, we observe dynamic response of carriage traveling through transitional section. The result show that both conditions will cause dynamic response of structure in transitional section while the train is passing by. Imperfect connection between concrete bed of track and foundation cause significant effect on rail track structures. The effect on dynamic response of carriage cause by uneven rail track is noticeable.