ResearchResearch projects
Untersuchung des Tragverhaltens von Offshore-Grout-Verbindungen unter Wasser an Tragstrukturen mit dynamischen Wechselwirkungen

Investigation of the load-bearing behaviour of offshore grout connections under water on supporting structures under dynamic loads

Led by:  Elyas Ghafoori
Team:  Jakob Borgelt
Year:  2020
Funding:  BMWi
Duration:  1. März 2020 – 31. Dezember 2023

Grout connections are hybrid connections made of steel and special grouting mortars, which are used offshore as connecting means for wind energy plants in order to enable a force fitted connection between foundation and supporting structure robust enough for the harsh weather conditions. In the joint research project Grout-WATCH the damaging process of grouted connections is investigated under realistic offshore conditions for bending dominated monopile structures and predominantly axially loaded jacket support structures within experiments and numerical simulations. The Institute of Steel Construction focuses on the axially loaded grout connections of jacket support structures. With a scaled test series of fatigue tests to determine characteristic curves, known as S-N-curves in current guidelines for steel and concrete details, in order to evaluate the degradation of grouted connections by means of the latest measuring methods. For this purpose, a monitoring system based on newly developed fibre-optic sensors in the grout annulus will be developed, which will allow a direct statement of the damaged grout material. For the evaluation of the damage a safe limit state has to be defined, which has to be monitored offshore. This topic will be of great importance in the near future under the aspects of extending operation times for aging wind farms. The aim is to make the acquired knowledge accessible for industry by means of simplified approaches to be able to provide approaches for the condition assessment of grouted connections.