An anchoring system for supporting platforms for wind energy devices

This paper presents data from an initial development stage of an ‘umbrella anchor’ concept. The anchor can be pushed into sand deposit in a folded arrangement to reduce installation loads. When a pull-out load is applied to the mooring line, the anchor deploys to create a large embedded plate anchor. Physical modelling was carried out in saturated sand-bed with the anchor installed at depths of up to 1.6 m and loaded vertically. During installation, liquefaction was generated at the tip of the anchor to reduce the penetration resistance. This enabled the anchor to be installed quickly and accurately to a target depth. The anchor could provide pull-out resistances comparable to anchor that was wished-in-place at similar depths. The observed behaviour provided encouraging preliminary results and suggests that, with further development and analysis, the concept could potentially be used for commercial applications.