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 a 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 a 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 an anchor that has been 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.