Construction of new runway from pier-type jacket structures with large-diameter long steel pipe piles

摘要

A new runway (named 'D-runway') for Tokyo Haneda International Airport was constructed offshore in Tokyo Bay to accommodate the recent increase in overseas and domestic flights to and from Tokyo. One of the most outstanding characteristics of the new runway is that it stands on two types of different structures: steel-jacket-platforms forming a pier-type structure and a reclaimed soil structure. The pier-type structure minimizes disturbance of water flow at the nearby Tama river mouth due to the presence of the new runway. This paper relates to the design and construction of the steel-jacket platforms for the pier structure. The main focus is on the results of pile load tests carried out to confirm the pile design, and the actual construction of the jacket structures. Through the construction of this pier-type structure, it has been possible to confirm the applicability of rapid load tests for large-diameter long steel pipe piles, the validity of the assumed pile tip plugging ratio used for design, and the applicability of a simple method for controlling the end of pile driving. Further, the effectiveness of joint-less work piles, the pile-keeper system, and GPS monitoring in the rapid and accurate construction of pier-type jacket structures was demonstrated.