University of Massachusetts Dartmouth’s Assistant Professor Ryan Beemer and Master Student Dayna Logan, Department of Civil and Environmental Engineering, and Professor Pia Moisander and Master Student Stephanie Richard, Department of Biology, are conducting a study at the Lloyd Center’s dock.
To address gaps in knowledge, this study involves installing small scale piles (pipes) made of various materials in the marine sediment off the dock at the wonderful Lloyd Center for the Environment, to investigate the biofilms that grow on them and any corrosion they may cause. The piles will be installed for two months in the summer of 2023 and then taken back to the lab to conduct microbial and geotechnical tests.
Set-up is a phenomenon where pile foundations gain capacity over time. This added strength varies significantly (ranging from 0-100% increase in capacity) so geotechnical engineers can only include it in very specific design cases. It has been thought that set-up could not be the result of corrosion, but microbially-influenced corrosion (MIC) that occurs in both oxic and anoxic marine sediments and could be specifically important at their interphase. MIC could contribute to set-up of offshore geosystems, such as monopile for offshore wind towers, through biomineralization or increased surface roughness from corrosion. Marine geotechnical engineering planning could greatly benefit from understanding the prevalence and mechanisms of such microbial processes during construction projects. It would be transformative for these industries to be able to include the influence of set-up due to MIC in design.
In addition, artificial iron structures in the marine environment may have deterministic and long-term impacts in the surrounding microbial communities that could lead to cascading effects in the benthic ecosystem.