Durchrutschende Grout-Verbindungen in OWEA - Tragverhalten, Instandsetzung und Optimierung

Sinking grouted joints in offshore wind turbines - Bearing behaviour, repair, and optimisation.

Grouted joints are mainly used for the connection of foundation piles and substructures of offshore wind turbines. Grouted joints consist of tube-to-tubeconnections where the annulus is filled with a high performance mortar. Since the early 90s, grouted joints have been installed in offshore wind energy converters with monopiles using plain steel sections with no additional mechanical interlock. During maintenance work vertical slippages have been detected at substructures with monopiles in Denmark, UK and the Netherlands. The movements may result from a loss of bond between steel and mortar. Within this paper the construction and the bearing behaviour of grouted joints is presented. Additionally experimental investigations are shown. Based on own experiences reasons for failure and repair opportunities are introduced and optimisation opportunities for future turbines are proposed.