Thrusting skyward in the South Korean capital Seoul is what will soon be the tallest building in East Asia – the 555 m Lotte World Tower, which will add a striking new facet to the city’s skyline. The Doka formwork solution fielded here uses SKE100 and SKE50 plus automatic climbers and the Protection screen Xclimb 60, and is ensuring swift, safe construction progress. In a formwork-engineering ‘first’, the Formwork Experts are using telescoping protection screens and platforms to deal with the structure’s continuous taper.
The Lotte World Tower is a project on a superlative scale. Once this skyscraper is completed, its 123 storeys will house not only shops, offices and small apartments (known locally as ‘officetels’), but also a 7-star luxury hotel. The top ten storeys, with a viewing platform and café on the rooftop terrace, will be given over to public use. According to this megabuilding’s architects Kohn Pedersen Fox, the visual design of the gently tapered tower, with its uninterrupted curvature, was inspired by elements of traditional Korean ceramics, porcelain and calligraphy. The client, the Lotte Group, is incorporating photovoltaic panels, wind turbines, exterior shading devices and rainwater harvesting systems into the building. “Elegance of form” was one of the prime objectives. The facade will be clad in light-toned silver glass accented by a filigree of white lacquered metal.
Keeping time with automatic climbers
For the formwork of the immense reinforced concrete core, which has now (early November 2012) reached a height of 140 m, Doka is again deploying know-how that has seen many such megaprojects through to a successful conclusion: 132 SKE100 automatic climbers, combined with Large-area formwork Top 50, are being climbed ahead of the floor-slabs, in casting sections that are 4.5 m high in the typical storeys. Another twelve SKE100 automatic climbers are being used to raise the three concrete placing booms in sync with the forming cycles. Eighty ‘SKE50 plus’ automatic climbers carrying Large-area formwork Top 50 are being used to construct eight 318 m tall, solid-cross-section mega-columns on the outside of the structure, to give it extra stability and safety. Work has been progressing very satisfactorily, says Doka Project Manager Klaus Eckstein: “Despite the tight timeframe, we finished all the planning work in good time. The formwork deliveries all went to plan and work on the site is moving ahead well.”
Telescoping protection screen
At present, the work platforms are enclosed with netting and tarpaulins. A 20 m high Protection screen Xclimb 60 will soon be providing a gapless enclosure around the top four and a half storeys at any one time, probably from the beginning of 2013. All operations can then be carried out sheltered from climatic influences and high winds. The constantly changing shape of the structure presented the Formwork Experts with a great challenge in the planning phase. The Doka project team’s answer was to develop a new, telescoping protection screen specially for the Lotte World Tower; this screen takes little or no modification to adapt to tapering structure shapes. The screen elements can be adjusted to widths of between 3 m and 5 m. Says Eckstein: “One of the exciting things about this assignment was that there were more than 20 of us in a single team based in three different countries – Korea, Singapore and Austria – all working together to devise and implement individualised solutions for the Lotte World Tower.”