The Challenge:

As China’s largest stadium project this decade, the new 400,000 square-meter Hangzhou Sports Park features a grand stadium with alternating steel and polycarbonate flower-petals encircling the bowl’s perimeter. Nestled on the banks of the Qian Tang River, not far from the East China Sea, strong winds – and even typhoons – are not uncommon in Hangzhou. Consequently, NBBJ/CCDI required the stadium roof to be able to withstand wind loads of up to 310 kg/sqm. In place of SUNPAL’s standard polycarbonate joiner, Palram identified an aluminum joiner for connecting the polycarbonate sheets as a more suitable choice for this application. Before accepting this recommendation, the architectural team requested the customized system pass a wind tunnel test simulating the load. And it did.

Shipping Challenge & Solution

To transport the specified Sunpal sheets in various lengths, the longest of which was more than 18 meters long, Palram had to look for an alternative as standard 40’ shipping containers hold 12-meter-long sheets. As a solution, specially-built wooden crates were deemed sturdy enough to withstand lifting by cranes or forklifts, without breaking, and lift tests confirmed that the crates would do the job. On the overseas journey, the crates were placed on special gondola containers inside the ship for added protection. For some of the “shorter” sheets, measuring 15 meters in length, Palram prepared an unusual wooden structure enabling the sheets to be bent into a “roller coaster” shape so that they could fit into a standard container.

Installation Challenges & Solution

As part of the stadium bowl’s unique flower design, the polycarbonate sheets which were installed across the width of the petal slope toward the edge connecting the polycarbonate with the metal roof, thereby creating a gutter. However, at some points, the roof slope is close to zero, causing concern that the water would not drain properly. Addressing this issue, Palram designed a special aluminum profile with a rubber gasket to prevent water from reaching the “wrong” edge of the sheet where the roof could potentially leak. Instead, this unique element essentially forces the water to flow into the gutter side for proper drainage. One other advantage of the Sunpal system is the fact that proprietary T-fasteners fix the joined panels to the structure so that they can be clamped in place, thereby avoiding any fastener penetration through the panels, for additional protection against water leakage. The multi-use space is used predominantly for football matches where spectators and players can enjoy the comfortable, sunlit bowl thanks to Palram’s Sunpal multiwall standing seam system.

In all, the 15,000 square meters of clear SUNPAL sheets specified for this high-profile project delivered the durability, high performance, and aesthetics required by the architects. Sturdy and impact resistant, Palram’s SUNPAL 20mm multiwall polycarbonate sheets were easy to blend into the metal flower scheme designed by architects NBBJ and CCDI. Together, the metal and polycarbonate create a unique space enveloping the 80,000-seat stadium. As one of China’s most prosperous cities, Hangzhou is a 2-hour’s drive from Shanghai and is set to host the 2022 Asian Games. Within the larger complex housing tennis tournament facilities; gardens, pathways and plazas; and retail, restaurants, and a multiplex cinema is the iconic stadium with its flower-shaped design, inspired by the local flora decorating the banks of Hangzhou’s West Lake opposite the Qian Tang riverfront.

The Details

Architect: NBBJ in partnership with CCDI
Location: Hangzhou, China
Stadium capacity: 80,000
Year of completion: 2016
Product: Sunpal 20mm, clear (visit Sunpal product page)
Coverage: 15,000 SQM

Watch an Overview of SUNPAL Installation

Aerial view of Hangzhou Stadium, which features Palram’s innovative Sunpal® Multiwall Panel System