Dynamic analysis of mono and tri-suction pile supported offshore wind turbines

Offshore wind turbines (OWT) are traditionally supported by monopile foundation. Although this technology is one of the most cost-effective for this type of offshore installation, the engineering market tries to propose always innovative and smarter solution in order to develop more and more cost-effective alternatives. One major disadvantage of the monopile foundation for example is the noise of the installation process. To mitigate this noise during installation, high costs are involved to use bubble screens or any other means.. One important part of the design of the OWT and its foundation is the dynamic response of the system subjected to time-varying loads, therefore the core of a structural analysis covers these aspects. In November 2017 the company SPT Offshore has launched in Amsterdam a new concept for Wind Turbine Generator (WTG) foundation. In the last year, the company has chosen to spend effort on developing conceptual designs of specific support structures for WTG in order to patent their own cost efficient solution. This new conceptual design is meant to combine the benefit of both the monopiles and the jacket support structures in combination with the suction pile foundation. Tri-Suction Pile Caisson is the name of this new technology (TSPC) and basically, it consists of a single column extending from the upper support structure downward to the seabed (few meters above it) connected to a base structure composed by three suction pile which spreads the loads into the soil (further information will be provided into the document). . The milestone purpose is to introduce in the market a new substructure concept which can compete with the traditional foundation design. For the development of this support structure concept, some basic requirements have to be satisfied for its successful realization; the aim is to design a concept which possibly can be installed without an offshore heavy lift vessel, easy to fabricate and suitable for series production.