Terrafix® sand mat protects world
cultural heritage underwater
Location of work/project:
Switzerland – Lake Zurich
NAUE GmbH & Co. KG
The pile dwellings in Lake Zurich, Switzerland, a UNESCO World Heritage Site, originated 4000 years ago. Natural erosion and the turbulence created by the busy shipping were endangering these unique structures in the shallow water zone. With Terrafix® geotextile filter and protection sand mats they were secured for posterity.
The pile dwellings in upper Lake Zurich, Switzerland originated 4000 years ago and were awarded the status of a UNESCO World Heritage Site in 2011. Natural erosion and the turbulence created by the busy shipping were endangering these unique structures in the shallow water zone. With the help of Terrafix® geotextile filter and protection sand mats they were secured for posterity.
It became clear that only if we are successful in protecting these sites in the long term will future researchers also have a chance of using new technologies to shed further light on the history of mankind. The archaeologists of the Canton of St. Gallen were therefore looking for ways to secure the pile dwellings over an area of 1,400m² in the long term without damaging delicate objects in the lake mud.
After numerous investigations and loading tests the solution was found:
The Terrafix ® sand mat. This geocomposite material with its geotextile components and a sand ballast layer was easily placed directly from the roll over the areas to be protected. It was then covered with 20cm of gravel.
Terrafix® is a fibre-reinforced, polypropylene sand mat which is mechanically bonded over its entire surface area. The sand entrapped between two nonwovens is held firmly in place by the fibres. The high specific weight of the encapsulated sand layer is responsible for a good sink behavior, enabling speedy, controlled placing under water and ensuring high positional stability. In addition, the Terrafix® sand mat has excellent filter characteristics.
Thanks to an impressive range of products for a wide variety of applications, and the expertise and experience acquired over many years with countless projects, SYTEC Bausysteme AG, the Swiss partner of NAUE GmbH & Co. KG, was able to propose a feasible and affordable solution for this unusual challenge.