Ground improvements in Haneda/Tokyo International Airport expansion project

Haneda/Tokyo International Airport was established in 1931 as the first primary airport in Japan where a runway of 300 m was operated. The airport has been expanded several times and the current airport has three runways and two terminal buildings on the man-made island. In order to cope with the future increase in air transportation, the fourth runway was constructed on a man-made island to the south of the existing airfield in 2010. As soft soil strata were stratified at the construction site, several ground improvement techniques were employed to improve the ground. As the project site was adjacent to the current airport, a large part of the construction site was regulated as a restricted area under the Civil Aeronautics Act of Japan. Under the limitation, the construction project had to be progressed under a very tight schedule. In this paper, the application of the ground improvement techniques is briefly introduced as well as an outline of the construction project.