An experimental study on the steel-concrete connection behaviors of support structures for tidal current turbines

To investigate shear strength and behavior of support structures for tidal current turbines, twelve 1/10 scaled specimens were tested. This study primarily presents numerical and experimental analysis results to assess structural performance of a caisson support structure compared to that of conventional gravity type. Structural details and failure modes of steel-concrete connections for the caisson type have been also investigated through the experimental tests, as detailed investigation for the steel-concrete connection is essentially required for enduring consistent cyclic lateral loads from currents and waves during in life-time. Influence of shear plate connections, embedded depth, number of ribs and width of ribs are systematically investigated for comparing details of steel-concrete connection. Test results consequently indicate that caisson type with embedded steel column having an embedded depth of around steel column diameter and two ribs is the most effective and reliable support structures for tidal current turbines. Embedded depth is most dependable factor for selecting connection type between steel column and concrete base.