濱 健太郎*1・渡邊 徹*1・堀井 良浩*1・藤山 淳司*2・木村 廣*2・秋月 通孝*3・中西 義隆*4



*1 技術センター 都市基盤技術研究部 構造研究室
*2 設計本部 構造設計第一部
*3 建築本部 技術部
*4 システム計測(株)

Practical Case of Constructing "T-EAGLE" Pile in Super High-rise Building

Kentaro HAMA*1, Toru WATANABE*1, Yoshihiro HORII*1, Junji TOYAMA*2, Yutaka KIMURA*2, Michitaka AKIZUKI*3 and Yoshitaka NAKANISHI*4

Large-diameter multi-belled cast-in-place concrete piling method T-EAGLE has been developed, and its application is being aggressively promoted. A pile made by this method has a bell with a maximum diameter of 5.5m at its midpoint and bottom so as to provide greater bearing capacity and resist large constant loads and pull-out loads that can occur in super high-rise buildings or long-span buildings that are recently increasing in number. A T-EAGLE pile (shaft diameter of 3.0 m, bell diameter of 5.3 m, and a length of 30 m) is adopted in a super high-rise building construction project in Tokyo to prevent settlement of the column area on which high axial force acts. Prior to piling, the construction procedure designed to ensure the vertical bearing capacity of piles and pile installation tolerance was developed. This led to the successful management of the bearing layer, which helps achieve the appropriate vertical bearing capacity, and to the stable excavation for enlarged parts. Supersonic hole wall measurement after excavation confirmed that the excavation shape that satisfies the predetermined shape was obtained.

Keywords: cast-in-place pile, multi-belled pile, top-down construction method, construction procedure, construction accuracy

*1 Structure Research Section, Urban Engineering Research Department, Taisei Advanced Center of Technology
*2 Structural Engineering Department I, Design Division
*3 Technology Control Department, Building Construction Division
*4 System Measure Co., Ltd.