Doka is underlining its strong market position in the high-rise sector with a slew of exceptional new projects that are all destined to join the list of the world’s tallest buildings. Among the next supertowers to rise with the aid of Doka climbing technology are the Lotte World Tower in Seoul, the CMA Tower in Riyadh and the Lamar Towers in Jeddah.
Much of the explanation for this string of impressive sales successes can be found in Doka’s outstanding performance on the ‘Burj Khalifa’ megaproject in Dubai. With Doka’s self-climbing formwork solution SKE, it took only 30 months to raise this over 600 metre tall CIP concrete core. This achievement also impressed other international developers, who are now turning to the know-how of the Doka Group to help them realise their bold plans. For construction progress on all these projects depends crucially upon “Safe. Fast. Efficient” forming of the in-situ concrete core. Climbing formwork SKE is the custom-tailored solution for this challenging formwork task.
Lotte World Tower, Seoul
The formwork that adapts all by itselfDoka has scored yet another sales success by winning the formwork contract for the 555 m Lotte World Tower. The client, Lotte Construction, rated the Doka concept as the “technically most sophisticated and best-quality formwork solution”, as it adapts more or less “on its own” to the many changes in the cross-section. Quite apart from the core’s enormous height, then, its complex shape presents another set of highly challenging requirements. In front elevation view, the core breaks down into three sections which are roughly equal in height but which are completely different geometrically. From August 2011, the Doka climbing formwork system SKE100 will be setting the pace on this CIP concrete core as well, raising some 2500 m² of Large-area formwork Top 50 and three concrete placing booms with the aid of 117 automatic climbers SKE100.
To enable the slab-forming work in the top four storeys of the rising core to take place under optimum safety conditions, sheltered from the weather, the self-climbing Doka protection screen Xclimb 60 is to be fielded here. This gapless enclosure of the under-construction storeys has to adapt to the decreasing circumference automatically, i.e. without needing any time-consuming modifications. To achieve this, the climbing profiles (which are normally arranged in parallel) are mounted at an acute angle to one another so that the individual elements of the protection screen can automatically move into one another on rollers during the climbing operation.
Column formwork with own rebar craneGigantic CIP concrete pillars, known as “mega-columns”, run up the outsides of the structure. Between the first and last casting steps, their quadratic cross-section tapers from 3.50 m to 2.00 m. The self-climbing solution ‘SKE50 plus’ is used here in conjunction with ‘Top 50’ large-area formwork elements. To speed up the construction workflow still further, each column will have its own crane for lifting in the rebar. These cranes are ‘climbed’ together with the formwork solution.
CMA Tower, Riyadh
A structure core like a skyscraperThe Saudi Arabian government is currently working to complete the 16-hectare “King Abdullah Financial District”. This project aims to boost Saudi Arabia’s position as the financial capital of the Middle East. As well as premium residential developments, the new finance district will also be home to the Saudi Arabian stock exchange and will even be served by its own mag-lev monorail link. Doka has managed to win several formwork contracts on this gigantic project, including one for the District’s tallest building.
Nonagonal structure core with 40 m diameterThe 400 m tall CMA Tower is characterised by its colossal nonagonal (9-sided) structure core, measuring over 40 m in the diagonal. Over 10,000 m³ of concrete went into the pouring of its foundations alone. Completing the massive CIP concrete core to be built on these foundations will take 100 casting sections and two years of construction work. Martin Hörlesberger is in charge of this project as well: “The amazing thing about the core of the CMA Tower is its sheer dimensions. This is the most voluminous enclosed shaft core that Doka has ever formed. Its gigantic dimensions remain unchanged all the way from bottom to top, making even just the shaft core of the CMA Tower the same sort of size as a whole conventional skyscraper! Around 3000 m² of timber-beam formwork and 105 Automatic climbers SKE100 are in use here.”
Lamar Towers, Jeddah
Making up for delaysAnother truly superlative project is the Lamar Towers in the Saudi Arabian port city of Jeddah. The 70-storey cores of these 300 m tall twin towers are being built using 108 high-performing Automatic climbers SKE50 and 1800 m² of Large-area formwork Top 50. This equipment was chosen to make up for lost time caused by a change of both contractor and formwork supplier.
Formwork erection at a height of 25 mIn order to get the project up and running again as quickly as possible, the new contractors Al Joudah Contracting decided to have the whole system – wall formwork elements and 4 platform levels – pre-assembled by the Doka Ready-to-Use Service at the Jeddah Branch. On this previously commenced tower project, the main difficulty lies in assembling the system and putting it into use for the first time. The towers were begun by another construction firm using a slipform. This means that it is now necessary to safely mount the platforms and the formwork, and anchor them to the existing concrete, at a height of around 25 m. For this, Doka’s expertise in shifting large, professionally pre-assembled platform assemblages and elements has already proved highly advantageous. Doka is also supplying the formwork for the floor-slabs, and the protection-screen system Xclimb 60 to safeguard all slab-forming operations.
Doka High-Rise Centre, Singapore
Even closer to the customerDoka system solutions for supertowers have grown to become a success story that is based on years of experience. Doka has aggregated its knowledge about “Safe. Fast. Efficient” construction progress – on even the very tallest buildings in the world – in its in-house Competence Centres. In response to the greatly increased demand for high-rise-projects in South and East Asia, Doka has set up a dedicated “High-Rise Centre” in Singapore, as it did previously in Dubai. Working out of Singapore, the new Centre’s manager Michael Eder and his capable team will be supporting Doka’s Asian customers in all formwork-technology issues.