Whilst small diameter helical (or screw) piles are used extensively for near-shore and onshoreprojects, the potential to use these foundations in the offshore environment is receiving increasing attention.Potential advantages of helical piles over conventional foundation systems include their high capacity, ease ofinstallation (avoiding pile driving), ease of removal and lowcost for mass deployment. In situ testswere performedin Germany with a drill rig Bauer BG42. A series of field tests, finite element analyses and laboratory tests onhelical piles are being conducted as part of a joint research project between BAUER Maschinen GmbH andUniversity College Dublin (UCD). This paper shows the in situ tests conducted under real conditions. Besides,the results of small scale 1 g laboratory tests on 1/10th scale piles which were performed in a large sand boxat UCD are extensively described. A series of experiments were performed which investigated the effect of theratio of helix (or helical plates) to shaft diameter, and helix diameter on the pull-out capacity of helical piles. Theresults suggest that the optimum pile design has a helix-to-shaft diameter (defined as wing ratio) between 1.5and 2.0. Larger helical plates were significantly harder to install, whereas smaller helical plates provided littleresistance to vertical loads.
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