CONCRETE-FREE FOUNDATIONS

The spin anchors (spiders) are an innovative ground anchoring system which allows a temporary or permanent fixing of structures without the use of concrete or other binders. This system consists of a circular, corrosion-resistant cast iron anchor plate which is anchored in the ground with 6 (Type VI) or 12 (Type (XII) threaded rods. The length of the threaded rods varies from 2.00 to 6.00 m depending on the forces to be transferred and the ground characteristics.

Load:
The spin anchors (spiders) are considerably more powerful compared to other concrete foundations. Tensile loads up to 20 t vertically and up to 13 t horizontally, can be accommodated depending on the design and the ground characteristics. Particularly efficient and economical in difficult ground conditions, or when excavation work or asphalt cutting should be avoided. In general, it can be used in any type of ground (except rock).

Assembly:
A major advantage of the system is the economical and fast assembly. Depending on the type, the foundation is ready for use within an hour. Assembly is possible year-round and is carried out by means of a gear-driven manual screwing machine and can also be carried out in cold temperatures. Construction delays due to curing times and/or bad weather conditions are therefore avoided. WOLF System has developed optimised connections to the spider base for various requirements. In addition, the compensating plate can be used as a welding base in order to connect components in a load-carrying connection. In this way, the spin anchor (spider) can be used as a foundation for houses, cottages, and lightweight sheds, and open roofs, stages, flying constructions or carports.

Trial:
The performance of spin anchors (spiders) has been investigated and confirmed in research projects by different universities (including University of Darmstadt and Graz University of Technology). More than 1,000 spin anchors (spiders) have been installed in a wide variety of soils and are a testament to the inherent advantage of the system.

Temporary use / Redevelopment construction:
Concrete-free foundations can be completely dismantled without any great effort. After use, the terrain remains undamaged and free from contamination. All components are designed for multiple use and are therefore reusable. In the case of building projects on existing asphalt or paved surfaces, the system has great advantages, neither excavating nor separating work on the asphalt is necessary.