橋梁施工線形控制之研究--以場鑄懸臂工法橋為例--

隨著橋梁設計跨徑不斷增長，懸臂工法橋因施工線形控制不佳，造成相鄰兩懸臂施工段線形誤差過大，無法順利閉合之情形時有所聞。歸納其原因主要來自於施工階段懸臂節塊放樣高程未經有效檢核，任意調整之故。鑒於橋梁於設計階段中結構分析模式之模擬精確與否、工程材料特性、施工程序，以及其他不可確定之外在因素影響，橋體實際施工高程與設計高程間存在某一線形差異量，此差異量於施工過程中需經妥適修正與調整，俾能使施工後橋體線形符合設計原意。線形控制之目的在於經由分析、監測、比較、預測及調整過程，確實掌握橋梁拱度發展趨勢，並適時提出線形差異量可能原因、修正時機與調整方式，確保橋梁完工線形能符合設計需求。有鑑於影響橋體線形變化的因素繁多，如何準確地預測拱度發展，並識別出造成拱度偏差影響因子，以及適時提出拱度偏差調整方式，將是線形控制作業成敗的關鍵，亦是本文研析之重點。

關鍵字

線形控制、懸臂工法橋、預測式

並列摘要

As the span in bridge design has been increased, and the bridge of balanced cantilever method construction alignment couldn’t well-control, such that the alignment error became uncontrolled between two adjacent cantilevers of construction section. Therefore, the situation that unable to close smoothly was happened all the time. This was come from the sections of cantilever layout level; it was not inspected effectively and changed arbitrarily during the construction phase. The purpose of this study is to apple the alignment control method through the analysis, monitor, forecasting and adjusting procedure to make sure the completion alignment of bridge will conform to the design requirement. Since the elements to influence on the alignment vary in bridge body a lot, how to forecast the camber develop correctly and find out the influence factors which effect the error for the camber are the key point in this study.