Lotte World Tower, Seoul, South Korea
The Lotte World Tower is a 555m-high (1,820ft) mixed-use building located in Seoul, South Korea. The 123-storey building is the tallest in the country and the fifth tallest in the world, after Wuhan Greenland Center in China.
Opened in April 2017, the tower was designed by Kohn Pedersen Fox Associates (KPF) and built by Lotte Group at a cost of approximately $2.5bn.
The project received the 2017 Fifth Tallest Building Worldwide from the Council on Tall Buildings and Urban Habitat, and 2016 Excellence in Structural Engineering awards from the Structural Engineering Association of New York and the National Council of Structural Engineers Associations.
Lotte World Tower design and facilities
KPF drew inspiration for the building's design from the traditional Korean art forms of ceramics, porcelain and calligraphy. The tower's form is gently tapered and features an uninterrupted curvature, which is highlighted by silver insulated glass and filigrees of white lacquered metal, resembling Korean artistry.
The tower has a built-up area of 505,300m² (5,439,000ft²), including retail and office area, 256 residences, and a 260-room seven-star luxury hotel. It features the world's fastest and longest elevator, which can carry 54 people from the basement to the 121st floor in less than a minute. The double-deck elevator is 496m-high and powered by a 100t traction machine. The tower also features the world's highest glass-bottomed observation deck on the 121st floor.
The first ten storeys of the tower accommodate the Lotte World Mall, which was opened in 2014. The mall includes the Lotte Concert Hall with a seating capacity of 2,036.
Structure of the world's fifth tallest tower
The tower's structural system is made of a gravity-resistant system and a lateral force resistance system. The gravity-resistant system comprises the core walls, mega columns and deck slab structure with steel beams.
The core walls are located in the centre of the tower running up to the 123rd floor, while eight mega columns are located around the perimeter of the tower. The core walls handle 60% of the tower load, while the remaining 40% load is handled by the mega columns.
The lateral force resistance system consists of outriggers and belt trusses built on floors 39 to 44, 72 to 76, and 104 to 107.
The tower is built on a mega-mat foundation, a super structure with a length of 71.7m, 6.5m thickness and a volume of 31,203m³. The foundation handles the 750,000t of vertical load of the tower.
The foundation was cast in a single 30-hour concrete placement using 5,300 trucks pouring ready-mix concrete. High-strength and ultra-low heat concrete with a strength of 50MPa-80MPa was used for pouring the foundation, as well as the mega columns, core walls and flats slabs.
Lotte World Tower sustainable features
The Lotte World Tower incorporates sustainable features of the LEED Gold standard. The tower features a displacement air and a radiant floor cooling/heating system instead of the traditional air-conditioning for the atrium lobby. The outside air units are equipped with energy recovery wheels to collect exhaust air.
A range of renewable sources, including geothermal, photovoltaics and windspire turbines have been installed to support the power needs of the facility. Variable-frequency drives have been installed to ensure that the HVAC equipment is operated more efficiently. A SCADA system has also been installed to monitor and control power usage in the building.
Water-saving features such as low-flow fixtures and greywater reuse facilities have been incorporated to achieve savings of 30%.
Lotte Group's subsidiary, Lotte Engineering & Construction, was responsible for the construction of the tower.
Baum Architects served as the associate architects for the project, while Leslie E. Robertson Associates served as the structural engineering consultants.
Syska was responsible for mechanical, electrical and plumbing (MEP) design for the tower.
WSP | Parsons Brinckerhoff conducted a peer review of the mechanical, electrical and plumbing (MEP) installations of the tower. The company also provided LEED consultancy and facilitation services.
Doka supplied self-climbing and wall formwork, while Heatex supplied its ventilation products for the tower.
JENSEN HUGHES was contracted for fire protection consulting, security planning and construction safety.