Council on Tall Buildings and Urban Habitat
 

Jiangxi Nanchang Greenland Central Plaza, Nanchang
Featured September 2017
Jiangxi Nanchang Greenland Central Plaza was recognized as a "Best Tall Building Asia & Australasia"  fianlist in the 2016 Best Tall Building Awards.
Other Featured Tall Buildings
“The refined appearance and strategic positioning of Jiangxi Nanchang Greenland Central Plaza on the skyline makes the twin towers stand out in the typically cluttered slate of buildings found in China.”
SawTeen See, Technical Jury Chair, LERA

Completion Date:
January 2015
Building Height:
303 m (994 ft)
Stories:
59
Area:
220,000 sq m (2,368,060 sq ft)
Primary Function:
Office
Owner/Developer:
Greenland Group
Architects:
Skidmore, Owings & Merrill LLP (design); ECADI (architect of record)
Structural Engineer:
Skidmore, Owings & Merrill LLP (design)
MEP Engineers:
Skidmore, Owings & Merrill LLP (design)
Other CTBUH Member Consultants:
Aon Fire Protection Engineering (fire); Edgett Willams Consulting Group Inc. (vertical transportation); Lerch Bates (façade); RWDI (wind); SWA Group (landscape)

Conspicuous, symmetrical, gleaming – the twin towers of the Jiangxi Nanchang Greenland Central Plaza combine feats in technical innovation with formal planning practices that place them well within the context of Nanchang despite their prominence as the city’s first supertalls. Although the achievements of the complex are felt most closely at home, they resonate on an international scale. The use of cold bent glass along the façade not only provides dramatic visuals, but offers a new technical process with the power to transform the construction practices of future supertalls.
Located blocks from the Ganjiang River, the twin towers of the Jiangxi Nanchang Greenland Central Plaza anchor Nanchang’s developing financial district, placed across the river from the historic city center. Upon completion, they became the city’s tallest structures and its first supertall buildings. The identical towers, which stand 100 meters (328 feet) apart from one another at their centers, are a focal point for new development in the city.

The twins’ shapes morph from base to top: the bases of the towers are aligned to the street with a square ground-floor plan featuring rounded corners. As the towers rise, the floor plate is rotated a total of 45 degrees, maximizing views of the nearby riverfront. The rounded corners become more pronounced as the towers rise, blending with the concave indentations of the uppermost floors, creating a tower form that transitions from rigid to organic and is clad in a sleek glass curtain wall that appears to flow across the exterior like a wave.
View of the crown from the inside View of the crown from the outside
Initially planned to top out at 289 meters (948 feet), the design was altered midway through construction to reach beyond the 300-meter (984-foot) mark, presenting a significant challenge to the design team. Through adding height to the buildings, the crowns were then sculpted into a series of concave curves and clad with operable glass louvers, opening to allow prevailing winds to pass through the top of the tower, reducing overall loading on the structure.

Many of the glass panes on the tower are not flat, and designers took advantage of a newly created production method known as “cold bending” to form the glass panes into the desired specifications of the complex façade. In order to execute cold bending at the supertall scale, it was essential that the inherent limits of glass be understood. The design team found that by pushing each glass panel up to 1.5 percent out of plane, a smooth, reflective, and consistent surface could be achieved. Further analysis of the façade geometry resulted in panel dimensions that were relatively small and within the acceptable ranges for both curtain-wall fabricators and sealant manufacturers. These dimensions also permitted the bending of flat panels to be executed in the field.
Aerial view of the surrounding plaza and entry arches
By successfully deploying this technique, the project sets a new standard, proving that cold bending can be used to mitigate cost, fabrication, construction, and long-term durability factors traditionally associated with all-glass tower façades. The resulting outcome is a sinuous wave-like crown that caps the curving design of the towers.

At ground level, expansive lobbies are sheathed in highly transparent glass curtain walls in order to create a sense of continuity with the surrounding urban context and, by extension, maintain the view corridor to the river that runs through the site. The towers’ location takes advantage of an adjacent urban park, with tower lobbies oriented to the entrance of the park and the river beyond. Roughly seven-story arches rise above large stainless-steel canopies, framing the primary entrances to the tower and mimicking the curving appearance of the crowns above.
Typical floor plan

Related Links
CTBUH Skyscraper Center Profile:
Jiangxi Nanchang Greenland Central Plaza

Jiangxi Nanchang Greenland Central Plaza was recognized as a "Best Tall Building Asia & Australasia" fianlist in the 2016 Best Tall Building Awards.

The CTBUH would like to thank Skidmore, Owings & Merrill LLP for their assistance with this article.