Vibrational Safety of Breakwater in Port Vicinity due to Monopile Installation for Wind Turbine

Installation of monopiles (as support for offshore wind turbines) close to the port provides good connectivity to the farm location. The installation of these large-diameter piles generates vibration on the nearby breakwater, which may lead to the failure of the breakwater or any other structure. Hence, it is necessary to estimate the vibration that the monopile installation induces on structures in the vicinity. This paper presents a numerical study that was conducted to estimate the vibration on existing breakwaters caused by the installation of monopiles at two wind potential sites. In the proposed study, a 6-m-diameter monopile was used to support a 5-MW wind turbine. The study focuses on estimating the safe distance of monopile installation, hammer drop height and hammering frequency for two sites. These sites have varying water depths and geotechnical conditions. The breakwater, monopile along with adjacent structures were modelled in the three-dimensional finite-element framework, PLAXIS-3D to capture the soil–structure interaction effects. The study brings out the nature of the wave propagating from monopile toe and breakwater interaction for both sites. The influence of sand and clay soil on vibration transmission is also discussed.