History of land reclamation using dredged soils at Tokyo Haneda Airport

Abstract

The Tokyo Haneda Airport has been developed by land reclamation since 1931. When we look back its history, dredged soils have been effectively used at the offshore expansion project (1984-2007) and the D-runway project (2007-2010). In the offshore expansion project, a dredged clay deposit in ultra-soft state was converted into an airport island. Because of softness of the dreaded soil, continuity of the vertical drains under large consolidation settlement, as well as large lateral soil movement, had to be concerned. In the D-runway project, lightweight treated soils of dredged clay were effectively used to reduce earth pressure on the seawall. To efficiently conduct large-scale placement, pneumatic mixing method was very useful. At the joint structure between the reclamation and piled pier sections, air-foam treated lightweight soil was placed as backfill, because more lightness was strongly required to ensure the stability.