Session: 10-01-01 Seabed Properties and Processes

Paper Number: 131596

131596 - Numerical Investigation of Solute Migration and Release From Deformable Sediments Driven by Ocean Waves 

Deformation of marine sediments with poor drainage conditions can lead to the accumulation of excess pore water pressure when exposed to dynamic wave loading, resulting in significant seepage flow that impacts the migration of solutes. Notably, existing studies often neglect the influence of sediment deformability and associated seepage on solute transport under ocean wave action. This study addresses this gap by establishing a two-dimensional numerical model that combines and synchronously solves the advection-dispersion equation for nonreactive solute transport with equations for wave-induced oscillatory and residual pore pressures. The simulated results have demonstrated that the distribution of residual pore water pressure along depth demonstrates two distinct patterns influenced by the thickness of the seabed. In Pattern I, observed when the seabed is thinner than 0.3 times the wavelength, residual pore pressure monotonically increases with depth. This results in continuous upward migration of solutes towards the seabed surface. Conversely, Pattern II emerges when the seabed thickness exceeds 0.3 times the wavelength. In this scenario, the distribution of residual pore pressure follows a pattern where the peak value occurs at a certain depth and may shift downwards with wave action time. The direction of solute migration in shallower regions alternates over time, but ultimately, solutes are transported upwards to the seabed surface. A parametric study indicates that when the seabed thickness is in the range of 0.2–0.3 times the wavelength, accumulated seepage flow has a less pronounced effect on solute migration. However, decreasing relative density and shear modulus, as well as increasing soil permeability, enhance the influence of accumulated pore water pressure on solute migration.

Presenting Author: hongyi Zhao Hohai University

Presenting Author Biography: Hongyi Zhao holds a PhD from Griffith University, where he was honored with academic excellence upon completion in 2017. Subsequently, in 2018, he embarked on his Postdoctoral research journey at the ARC Centre for Advanced Technologies in Rail Track Infrastructure. In recognition of his outstanding achievements, Hongyi Zhao was granted a Prioritising Emerging Research Leaders Fellowship in 2021 and was appointed as an Associate Lecturer at the esteemed University of Wollongong. Presently, he serves as an Associate Professor at Hohai University.

Throughout his illustrious career, Hongyi has played a pivotal role in numerous national and international projects, collaborating with prestigious institutions and organizations such as NSFC, EPSRC, MERMAID, and ARC. His research expertise encompasses rail geotechnics, offshore geotechnics, coastal engineering, and solute transport. An accomplished scholar, he has authored or co-authored over 50 papers in esteemed international journals. Notably, 23 of his publications have been recognized as JCR Q1 papers, with 2 being distinguished as highly-cited by ESI, and 1 designated as an ESI hot paper.

Hongyi's remarkable contributions to the field have earned him several prestigious accolades, including the SDEE Ahmet Cakmak 2020 best paper award (Editor's choice) in Soil Dynamics and Earthquake Engineering, the featured paper award in the Journal of Marine Science and Engineering, and the Li Shanbang Excellent Paper award from the Chinese Earthquake Association.

While effectively contributing to research supervision and teaching, Hongyi is a frequently invited reviewer for more than 15 journal articles. He is a member of Australasian Railway Association and Chinese Geotechnical Society on Ocean Engineering and Geological Disaster Prevention and Control. He has actively delivered presentations/lectures over different international conferences/workshops, and served in organizing/technical committee of several international events.

Authors:

Hongyi Zhao Qingdao University of Technology
Xiaoli Liu Ocean University of China
Dong-Sheng Jeng Griffith University