The seventh element of the Busan-Geoje immersed tube was placed on the seabed off the South Korean coast this month. It is the second offshore season in construction of the 3,240m long tunnel, and placement the immersed tube is more than one-third complete. Last month South Korean contractor Daewoo E&C successfully placed the sixth element in the channel between Gaduk and Jungjuk islands. After this month's success, it plans to place another four elements in the current season. In the first season the JV placed four elements. Given the harsh offshore conditions in the area, the contractor has to wait for wave heights of no more than 0.4m for the four-day operation to immerse an element. It is being assisted by specialist forecaster Nowcasting of the Netherlands. The immersed tube is be built from 18 elements - 16 ordinary elements of 180m length (made of 8 × 22.5m long sections) and weighing 48,000t, and two special elements. The elements are being placed at depths of about 15m-50m in the open sea channel. The tunnel has two cells for two-lane traffic plus emergency lanes, and the external dimensions of the majority of the tunnel elements are approximately 26.5m wide by 10m high. Walls are 1 m thick.
展开▼
