The Tokyo 2020 summer Olympics is just over two years away and work is progressing well on the new National Stadium that will serve as the centrepiece of the Games.
The Kengo Kuma-designed facility broke ground in December 2016 and work is due to be completed in November 2019. With a seating capacity of approximately 60,000 – expandable to 80,000 post-Games – the stadium has been designed to encapsulate Japanese culture and heritage.
The Japan Sport Council (JSC), which owns the stadium, notes that the venue’s eaves are being constructed to cater for the Japanese climate and will blend in with the surrounding Meiji forest. At night, the entire facility will be soft-lit by traditional Japanese lights.
Lumber wood will be used extensively inside the stadium, and for the outer-perimeter eaves, in a move the JSC says will create a distinctly Japanese feel. Domestic, forest-certified lumber will be used for the large roof and the eaves.
The stadium has been designed to ensure that athlete performance will not be affected, regardless of the season or weather. A pop-up sprinkler will uniformly be used as part of a field maintenance system that will be operated and managed through system control, timer control and rainfall sensor control.
In a bid to create a sense of unity between spectators and athletes, bowl-shaped, three-layer stands, increasing gradually in steepness, will be constructed. Specially-dedicated athlete traffic lanes and circulation routes will also be set up.
On the spectator side, bathrooms and nursing rooms will be placed on each floor of the stadium bowl, with resting rooms for guests with intellectual, mental and development disabilities to also be offered.
Additionally, a wide array of wheelchair spaces will be offered on all floors, which the JSC says will create an environment that will ensure “visibility and comfort of wheelchair users to share excitement while watching events”.
In another move designed to welcome wheelchair users, the stadium’s exterior will feature a gentle slope, allowing spectators to move about safely and comfortably access the venue.
The project has environmental sustainability at its heart and the JSC says the stadium will be “open to everyone”. The stadium’s vicinity will allow spectators to enjoy walks and partake in various sports before heading inside to enjoy the action.
‘A totally different project’
Due to concerns relating to finances and an ambitious design, the initial plan for the Tokyo National Stadium was scrapped in July 2015 before renowned architect Kuma took on responsibility for the project in December of the same year.
Under the original plans, the stadium had been set to host matches during Japan’s staging of the 2019 Rugby World Cup. But with the stadium now not set to be ready until after that tournament, the following year’s Olympics will be the first major event to be staged at the venue.
“We changed the stadium plan and are going on the totally different project,” the JSC’s Yuta Ando told TheStadiumBusiness.com.
‘Perfectly on schedule’
“The project is going on as scheduled and now at the stage of constructing its roof that is one of the features of this stadium,” Ando said.
“The roof is composed of three units (each unit is lifted separately and connected). It is perfectly on schedule. The field construction will get started after the roof stage.”
Lumber roof is being used on the inner side of the large roof and the eaves so it us not exposed to rainfall and subsequent degradation. The lumber will be treated with pressure injection processes to increase its durability.
IMAGES: Taisei Corporation, Azusa Sekkei Co., Ltd. and Kengo Kuma and Associates Joint Venture. The renderings are intended to show conceptual image at completion and may be subject to change.