Summary of case histories of retaining wall installed by rotary cutting press-in method

This paper summaries Japanese case histories of retaining walls of the rotary cutting press-in piles in terms of the application, pile materials, project scale, spatial restrictions for working, and ground conditions. The purpose is to grasp the characteristic of the rotary press-in method, and grasp the requirement for the renewal of civil infrastructures under working restrictions. The rotary press-in piles were often used when the pile diameter was 1000 mm, the pile length was 18-20 m, and the total length per project was 20-40 m. About 70% of the projects for reconstruction/rehabilitation of the retaining structures had spatial restrictions, such as insufficient headroom, side space and working space, and unstable work at high places. And over 60% of the projects had problems of hard grounds (SPT N>75) or any underground obstacles.