Offshore Pile Driving sound propagation in stratified media by coupling the Finite Element and Thin Layer methods

The growth of offshore renewable energy has driven the widespread use of monopile foundations, where installation by impact pile driving generates stress waves in both the water column and the seabed. The pile vibrations generate underwater noise and seabed particle motion that may harm marine and benthic organisms. A sound generation module is developed to capture the coupled pile-soil-fluid interaction during impact, providing a physically consistent representation of the sources in both the acoustic and the elastic media. Sound propagation is modeled using the Thin Layer Method (TLM), enabling efficient simulation of wave transmission through an acousto-elastic medium with a stratified seabed. The approach facilitates evaluation of key environmental metrics, including sound pressure and exposure levels in the water column, as well as particle motion at the seabed interface. The framework improves the accuracy of seabed response predictions while enhancing computational efficiency for environmental impact assessment and mitigation design.