Building Land from Marshland

Building Land from Marshland

Hemmingstedt | Bonar

How can one turn former marshlands into economically viable land, when load-bearing capacities are so poor that in times of heavy rainfall one cannot even walk on the land?

This was a challenge that had faced the municipality of Hemmingstedt in Germany for quite a while.

The answer was simple – create a floating foundation, using high quality bi-axial geogrids to deliver the critical soil stabilization, on which a 12 ha greenhouse complex would be built.

The greenhouse complex can be roughly divided into five areas according to the foundation designs chosen:

  • Zone 1 is the usable area within the greenhouses, where the building structure is supported by piles bearing on the lower-lying soil.
  • Zone 2 consists of the unpaved distribution roads within the greenhouses.
  • Zone 3 contains the feeder roads outside the greenhouses, which have to carry higher loads.
  • Zone 4 includes the dikes for the surrounding rainwater catchment basins
  • Zone 5 consist of the foundation for water irrigation tanks

Each element has its own specific demands for load-bearing capacity, so EnkaRoad, Colbond’s design program, was used to calculate which geogrids and (intermediate) layers of fill would be necessary to deliver the required load-bearing capacities for each of the elements. In addition, the individual layers were separated by Bontec® non woven geotextiles.

Hemmingstedt  | Colbond

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An important part of the solution for this unique and large project is Colbond’s Enkagrid TRC which is used when conventional geogrids are not adequate. Enkagrid TRC is a composite of a Twaron® aramid mesh for reinforcement, embedded in a non woven geotextile for separation. The aramid fibres are five times stronger than steel and combine high strength with low elongation.

Today, 5-axle, 60-ton trucks may drive, undisturbed, in an area of former marshlands, where a major greenhouse complex was built on a floating foundation. New economic value – thanks to the outstanding soil stabilizing properties of Enkagrid.