South Korean construction giant Daelim Industrial Company says its consortium with SK E&C has successfully completed the installation of the second caisson, the foundation to support the tower of Canakkale Bridge in Turkey.

The caisson presents a layout wherein two cylindrical steel components are mounted within the hollow square grid-shaped concrete structure, playing a role in anchoring a tower at the ocean bottom.

Following the successful installation of the first caisson in mid-May, they completed the installation of the second and last caisson recently.

The second caisson was installed on Canakkale Bridge in Turkey’s Dardanelles Strait.

 The two caissons took about 15 months to be fabricated from February last year on a plot of land around the site. A peak of 1,300 workers a day and 9,000 truck-loads of readymixed concrete were deployed. Each  caisson weighs about 60,000 tonnes.

The 47-m-high concrete structure will support a steel tower.

The core of the work was to place the caisson accurately at the bottom of the ocean according to the design, says Daelim.

To this end, four tugboats moved the caisson on the sea and carried out the highly challenging  construction task considering the movement of the waves in about 72 hours, it states. The Daelim-SK E&C consortium adopted a ballast device used to balance and level a ship to fill the empty space within the caisson and sink it. Accurate location measurement was carried out in real time using GPS and slope gauge.

Through this, the installation was successfully performed with high precision within the range of ±20mm and beyond the range of ±200mm as the construction error threshold.

“We will do our best to set the benchmark as a global developer through the cooperation between the Korean construction companies by completing to top-class quality the world’s longest suspension bridge, which will be a landmark of Turkey,” he adds.