Session: 06-03-06 Fluid-Structure, Multi-body and Wave-body Interaction - VI

Submission Number: 182340

Numerical Simulation of Local Scour and Undermining Beneath a Squat Structure 

Squat structures, which have limited height compared to their plan dimensions, are widely deployed in subsea engineering (for example, gravity-based subsea foundations, pipeline and cable infrastructure, artificial reefs, and scour mitigation structures, etc.). Field evidence and controlled experiments show that local scour can develop around these structures, causing seabed lowering and potential undermining, which may lead to settlement and threaten the structural integrity or functionality of the structure. However, the hydrodynamic drivers that initiate and sustain scour around low-aspect-ratio structures are not yet well understood. Gaining a clearer understanding of these processes is essential for the effective design of scour mitigation measures and for enabling reliable extrapolation of laboratory observations to full-scale squat subsea structures. Yet, the limitations of current measurement techniques make it challenging to capture the evolving flow structures and bed shear stress distributions during the scour process. This study addresses this knowledge gap by conducting high-fidelity numerical simulations that capture the onset and evolution of scour. The simulated scour profiles are validated through comparison to reduced scale physical model experiments. Following this, the numerical results are used to undertake a detailed characterization of the surrounding flow structures, their temporal development as scour progresses, and their role in amplifying near-bed shear stresses that drive sediment removal.

Presenting Author: Bingchang Zhang University of Western Australia

Presenting Author Biography: Bingchang Zhang is a currently Research Associate in the University of Western Australia

Authors:

Bingchang Zhang University of Western Australia
Lili Qu The University of Western Australia
Hongwei An The University of Western Australia
Scott Draper The University of Western Australia
Phil Watson The University of Western Australia