TenCate Geotube® technology was used for the construction of a dike as part of a vast infrastructure project in South Korea. The use of this technology in one of the largest land reclamation projects in history produced a number of both economic and environmental advantages: a cost saving of almost five million euros, a saving of over 50% on CO2 emissions and a substantial reduction in the construction time of the overall project.
Before the damming of an estuary, Saemangeum was an area of tidal flats. As such it formed an important habitat for migratory birds. Periods of drought and extreme cold forced the authorities to import rice during the 1960s to the 1980s. One of the measures that were taken was the construction of a sea dike that would link two headlands just south of the industrial port city of Gunsan. Work began on this project in 1991.
The Saemangeum Development Project includes the reclamation of 401 km2 of land from the sea. This also includes the construction of a 33.9-km-long sea dike and of inner dikes, the creation of a freshwater reservoir and reclaimed land. The building work, however, had to be suspended for some time as environmental activists contested the need for the project.
The enclosing dike was largely constructed in 2006 and after completion it was opened in April 2010. As a result, the coastline has been shortened by almost 100 kilometers. The dike has two sluice gates, a navigation lock to provide access to shipping and has an average height of 36 meters. This was done to take account of the large tidal range.
With a length of 33.9 kilometers the dike is 1900 metes longer than the Afsluitdijk, (a seawall in the Netherlands) which has a dike body of 30 kilometers. This is certainly a record as the longest man-made dam in the world.
The area behind it has an area of 401 km²: 283 km² new land and 118 km² freshwater, making it one of the largest land reclamation projects in history. The new land is intended for agricultural development, housing, development of both commercial and eco-tourism, ecological and environmental purposes, scientific research, new and renewable sources of energy and for other purposes.
One of the parts of this sizable project was a 4-kilometre-long polder dike. For the original design a sandfill core was used with rockfill berm on either side of the dike. As an alternative, TenCate Geotube® was chosen: textile containers produced by TenCate Geosynthetics in Zhuhai, each measuring 62 meters in length, which were filled with sand that had been extracted locally.
This natural material is readily available here. This made a considerable difference in transport. It meant a saving of €4.6 million ($6.2 million), based on current tender prices. This also led to the construction time being shortened by seven months. The choice of this technology with tubular geotextiles resulted in a saving of more than 230,000 tons of CO2: in other words, a 52% smaller CO2 footprint.
[mappress]
Press Release, September 3, 2014