With taller buildings, which have larger spans, there is a need for foundation piles that can support large loads. Multistage expanded cast-in-place concrete piles (hereinafter referred to as "multistage expanded piles") are designed to resist push-in and pull-out forces applied to piles during earthquakes by adding a "diameter expansion" not only at the tip of the pile but also in the middle of the shaft. This method is suitable for heavy buildings, such as superhigh-rise buildings, long and narrow buildings, which are subject to enormous pushing and pulling forces during earthquakes, and buildings that have deep underground components, which are subject to buoyancy forces.

High quality as recognized by third-party evaluation organizations

Multistage expansion piles are constructed by casting high-strength concrete after excavation using a special machine developed in-house. During the development of this technology, we established a construction method by confirming the shape and strength of piles digging out actual test piles. We then established a design method to evaluate support force through load tests of the piles, and we have obtained a general evaluation for these design and construction methods. In addition, the company received the 2015 Architectural Institute of Japan Award (Technology) in recognition of its high technology and numerous applications.

　　　　　　　　　　　　　　

Applied projects

This method has been applied to more than 10 projects, mainly in superhigh-rise buildings.