A three-dimensional hybrid model for predicting underwater noise from impact pile driving

High-intensity impulsive noise generated during impact pile driving has become a growing concern in environmental impact assessments. Numerical acoustic models play a crucial role in predicting underwater acoustic phenomena in complex coastal environments prior to offshore construction projects. In this study, we developed a three-dimensional (3D) hybrid model through the integration of finite element and parabolic equation methods. Specifically, the acoustic-solid interaction method was implemented in a dynamic axisymmetric finite element model to simulate time-dependent pile vibration sources. Subsequently, a broadband 3D parabolic equation (PE) wave propagation model was developed to integrate the acoustic sources. The simulated results demonstrated reasonable agreement with field measurements, exhibiting sound exposure level (SEL) differences of less than 3 dB. These findings indicate that the hybrid modeling approach provides an effective solution for predicting broadband acoustic fields in complex shallow-water environments.