On the Capacity of Grouted Connections in Monopile Offshore Wind Turbine Structures

Numerical Analysis of Shear Keys for Offshore Wind Turbine Monopile Grouted Connection with Elastomeric Bearings

“…Offshore wind is a renewable energy technology with an important role in current and future energy systems [1][2][3]. At present, offshore wind turbines involve several types of substructures, such as monopiles, gravity-based structures, jackets, tripods, and floating supports [4,5].…”

“…In the case of the horizontal shear key, it resists an axial load, whereas, in the case of the vertical shear key, it resists the torque of the turbine system. In general, GCs have been designed in accordance with the international design standards (i.e., DNVGL-ST-0126 [9] and DIN EN ISO 19902 [10]); however, GC failure has been reported under ultimate load and fatigue load such as (i) the occurrence of contact destruction between tubular steel pipes and grout material due to the generation of an ultimate or cyclic load that exceeds the lateral stiffness of the friction contact, and (ii) the occurrence of material failure along the grout strut or around the shear keys by shear stresses that exceed the shear capacity of the grout [3]. Therefore, to overcome these problems, the design stage of GCs for monopile offshore structures should be specified in the design of the grout thickness, number of shear keys, shear key size, vertical distance of adjacent shear keys, and grout compressive and tensile strength to prevent material and contact failure of the grout against limit states such as the ultimate limit state (ULS) and fatigue limit state (FLS).…”

Grout‐Verbindungen in Monopile‐Tragstrukturen von Offshore‐Windenergieanlagen

“…zum Trag-und Ermüdungsverhalten an biegebeanspruchten Grout-Verbindungen wurden in 2001 von Tech-wise[12] durchgeführt. Weitere Untersuchungen an biegebeanspruchten Grout-Verbindungen erfolgten durch Schaumann et al([9],[10],[13],[14]) sowie durch Lotsberg[8]. Im Gegensatz zu den Untersuchungen von Tech-wise wurden von Schaumann et al unter anderem die Einflüsse von Schubrippen, Rohr-Übergreifungslängen und Füllmaterialdruckfestigkeiten auf das Ermüdungsverhalten der Verbindung untersucht.…”