Two joint industry projects on grouted connections have been performed by Det Norske Veritas (DNV) since autumn 2009. The main findings from this project were presented at OES 2 June 2011.
In January 2011 another joint industry project on capacity of cylindrical shaped grouted connections with shear keys was started. It was assessed that it is difficult to achieve reliable fatigue test results from scaled tubular test specimens, i.e. using small diameter cylinders, subjected to reversed dynamic loading when attempting to simulate the behaviour of large diameter monopile connections. Large actuators would be required to perform tests with specimens of a similar size to that built offshore. Therefore a methodology with test box specimens simulating structural properties similar to that of large diameter connections was developed. Four box specimens, including full grout thickness and actual geometry of the shear keys, were designed and fabricated with a similar radial stiffness as that of large diameter connections. These test specimens were subjected to reversed dynamic loading until failure. One cylindrical test specimen has also been tested in the laboratory under dynamic loading. Some further testing is beeing planned to gain more fatigue test data on capacity of grouted connections in monopiles and jacket structures subjected to reversed dynamic loading.
A design methodology to account for the dynamic bending moment and the axial force in grouted connections with shear keys has been developed for the Ultimate Limit State and the Fatigue Limit State.
The main results from this last project are presented here in this lecture by Dr Inge Lotsberg together with a status on design recommendations and design standards for cylindrical shaped grouted connections with shear keys.
For more information, please contact (recordedlectures@ice.org.uk)
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ICE/OES Event - On Capacity of Cylindrical Shaped Grouted Connections with Shear Keys
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