Performance of a self-installing monopiled gravity base structure under lateral loading

This paper presents a physical model study of the feasibility and performance of a monopiled gravity base structure (MGBS) for offshore foundation applications. The research study builds on the current interest in hybrid foundation systems such as monopiled footings. The proposed MGBS is essentially a conventional gravity base structure (GBS) with a projecting monopile or caisson. The system relies on the self-weight of the GBS to drive the projecting monopile into the seabed. Once installed, additional ballast can be added to the GBS, and if necessary installation of the projecting monopile can be enhanced through the use of suction. The test programme has concentrated on the response of the system once installed and has investigated a range of geometries for circular monopiles. The results clearly demonstrate a significant enhancement to lateral resistance offered by the addition of a monopile to a GBS.