支撐先進工法施工之細部探討

Abstract

國內第二高速公路規劃興建路線以經山區及都會邊緣地帶為主，跨過河川 、溪流，穿越現有道路，施工條件較為中山高速公路更為艱鉅，同時台灣 地區勞工日益短缺，新式的橋梁施工法引進已為時勢所趨。故本研究主要 以後拉預力混凝土新式橋梁施工法 -支撐先進工法之施工作細部探討。本 論文對於支撐先進工法之規劃作完整敘述，由本工法之歷史沿革與使用概 況、特徵與適用性、優缺點等概略性之瞭解，以作為橋梁施工規劃時之評 估考量因素。並針對支撐先進工法之支撐形式、不同支撐形式之構造及施 工步驟作一系列之探討。本論文以國內首座採支撐先進工法施工之橋梁為 實例，實際瞭解現地施工細部程序與步驟，深入探討施工期間所產生問題 對於工期的影響，並進一步提出工法之各種改善建議，以期能縮短工期、 降低施工成本，達到經濟性、安全性、功能性的要求。另外，再模擬現地 預力混凝土之養護情形，研究經蒸氣養護與乾燥室養護後的混凝土試體， 分別施予預力，量測 28天試體因潛變及收縮所造成應變值與預力損失之 情形。經研究結果，蒸氣養護的混凝土試體28天的應變值與預力損失分別 較乾燥室養護低 16%與 4.59% ，且早期強度也較高。 Recently, our nation's plan of second highway was often designed to pass the stick and city skirt region, across the river, brook, pass through the existing roadway.The construction condition is more formidable than Jong-Shan highway. Besides,the laborers are more and more insufficient in Taiwan. This is the reason why we need to introduce the new construction method of bridge. The study focuses on the new construction method of post -tensioning prestressed concrete bridge and the detail study of Advancing Shoring Method. This study describes the layout of Advancing Shoring Method. First, we want to understand the history and typically state of usage of this construction method in order to estimate the factor when we plan to constrcte a bridge. Besides,we also study the support type,the structures of various support types and the construction steps. The study takes the brdige which adapts the Advancing Shoring Method earliest as example, and make us understand the practical construction procedures. Furthermore, this study discusses the influences of the troubles on the construction time during the construction period and suggests some improvements on various method in order to shorten the construction time, reduce the construction cost and get the economic, safe and functional bridge. Besides, this study also simulated the curing state of the in place prestressed concrete and studied the steam-curing and dried-room-curing's concrete samples, imposed prestress on those samples,and measured thr loss of prestress caused by creep and shrinkage of the concrete samples. The result shows that the steam-curing concrete samples' strain and loss of prestress are 16% and 4.59% less than the dried-room-curing concrete samples' The steam-curing concrete samples' early strength is higher, also.