In August 2010, the fourth runway called D-runway will be constructed off the coast of the Tokyo International Airport (Haneda Airport) known as the fourth largest airport in a handling number of passengers in the world. Since a part of the new runway is located in the mouth of the Tamagawa River, the piled-elevated platform was adopted for one-thirds of the runway in order not to obstacle the flow of the river. Therefore, the hybrid method of piled-elevated platform and land reclamation was applied to the construction of D-runway.

In the reclamation area, slope-type rubble mound seawall was constructed on the improved seabed with sand compaction pile method and 52 million cubic meters of soil, sand and rock were totally used for land reclamation. The piled-elevated platform was built by installing 198 prefabricated steel jackets on 1165 steel-pipe bearing piles. And their steel jackets were connected each other at the site. For the access from the existing airport to D-Runway, two connecting taxiways with 620m-long and 63m-wide were constructed. Huge quantities of material (470,000 tons of steel and 450,000m3 of concrete) were used in the D-runway Project.

The construction area of D-Runway is located below the obstacle limitation surface of existing runways for taking-off and landing of airplanes. Therefore, the height of workvessels and construction machinery were limited. Nevertheless, we could complete the D-Runway Project in a very short construction period of approximately three years. This was resulted from rapid-massive construction method by 24-hour continuous work. This report describes the outline of the D-runway Project and the construction work record.