Project: Kömürhan Bridge
Location: Malatya-Elazığ, Turkey
Type of structure: Cable-Stayed Bridge
Length: 660 m
Main Span: 360 m
Height of pylon: 165 m
Concrete: 160,000 m³
Reinforcement: 6,000 tons
Developer: Republic of Turkey General Directorate of Highways (KGM)
Contractor: Doğuş and Gülsan Holding
Systems used: Automatic Climbing Formwork SKE 50, Large-area formwork Top 50, Load-bearing tower Staxo 100, Load-bearing Tower d3
Located approximately 700 km east of the Turkish capital of Ankara and 400 km north of the Syrian border lies the province of Malatya, a region famed for its apricots and now the tallest pylon in the country. Standing at a height of 168.5 metres, the ‘Y’ shaped reinforced concrete tower is the centrepiece of the new Kömürhan Bridge, a suspension structure traversing the Fırat River and the Malatya-Elazığ regional borders. Stretching just over half a kilometre at 660 metres, the bridge has an edge opening of 180 metres, a middle opening of 380 metres and a width of 24 metres. The deck cross-section will be orthotropic steel, while the superstructure of the bridge will be connected to the pylon with 42 tensioned cables. In context of the wider project, it is part of a 5,225 metres four-lane highway that includes a 120-metre viaduct and a 2,400-metre tunnel, providing passage to the Karakaya Dam a few kilometres to the south. The existing old bridge and crookedly connected roads will be preserved. The new bridge and the tunnel will be developed next to the existing route. It is planned that the Kömürhan Bridge will be completed in July 2020.
Working under the joint venture of Doğuş and Gülsan, Doka Turkey was awarded the contract to design and supervise the execution of formwork, which commenced in August 2017. With the bridge scheduled to open in 2020, project manager Taha Özdilek commented: “Safety was our main priority on this project and Doka has maintained an excellent track record where this is concerned. Most of my team were accustomed with Doka’s products and systems and knew that the solution and the site support would add much value. Our team was also familiar with Doka’s solution for a similar project (Nissibi Bridge), which was delivered in 2015 and therefore knew they would be well suited for the job.”
In terms of the practical formwork solution, the major challenge was the pylon, specifically its unusual shape. Doka’s Automatic Climbing Formwork SKE 50 was used on the upper single core column of the pylon, while a specially adapted double set was used on the lower half with bespoke solutions created at junction points to maintain the highest standards of quality and safety. Large-area formwork Top 50 was used for the pylon with Doka D2/D3 and Load-bearing Towers Staxo 100 shoring systems for the approaching viaduct. While a tower and mobile crane were used for the pylon and viaduct respectively, the formwork solution was otherwise self-sufficient and delivered its portion of the project safely, on time and on budget.
Doka is a world leader in developing, manufacturing and distributing formwork technology for use in all fields of the construction sector. With more than 160 sales and logistics facilities in over 70 countries, Doka has a high-performing distribution network which ensures that equipment and technical support are provided swiftly and professionally. An enterprise forming part of the Umdasch Group, Doka employs a worldwide workforce of 7,000.