多節三岔擠擴樁承載與經濟效益之特性研究

多節三岔擠擴樁是一個新興工法，近年來在很多地區皆已應用，並取得了很好的經濟效益，儘管實踐效果明顯，但目前擠擴支盤樁這項新技術，整體上仍處於技術開發和推廣應用階段，尚須透過更多案例的探討，使其趨於完備。多節三岔擠擴樁的承載力機制，分為盤端阻力與樁身摩阻力，其中盤端阻力乃通過樁身擠擴盤體(承力盤或承力岔)的端阻力，而樁身摩阻力，則為樁身與土壤摩擦有關，因為擠擴盤體提供的承載力很高，因此使單樁的載力大幅提高，進而節約工程造價。本研究除簡介多節三岔擠擴灌注樁的基本原理、相關規程與施工特性等，並藉由廈門某醫院與新光三越兩案例，進行試樁試驗分析、承載力計算及成本分析，藉以評估該工法之優勢。

關鍵字

DX擠擴裝置；承力盤端阻力； DX樁；擠擴

並列摘要

The DX pile is a new type of piles which has been adopted in some places and gets well economic benefits. However, the DX pile has such advantages in construct the new developed DX pile was still in the stage of popularization. It needs more demonstrated study to provide confidence experience in construct. DX pile’s loading-bearing capacity mechanism is made up of exertion of the end resistance and shaft resistance of DX piles. The exertion of the end resistance was the end resistance through the pile plate. The shaft resistance came from the pile side and solid friction. Under the same command of load bearing, using DX pile, with its heightened capacity for load bearing of the single pile can save cost of the pile foundation. The study introduced the DX pile including the basic theory, related standard and constructed features etc. We compared the hospital in Amoy and Taipei Shin Kong department construction to evaluate the DX pile advantages from the analysis of the tested pile, load bearing capacity and capitalized cost.