Geotechnical Properties and Performance of Large-Scale Coastal Dunes Reinforced by Biocementation under Hurricane Wave Conditions

In this study, the application of microbially induced carbonate precipitation for coastline protection was investigated. Untreated, moderately, and heavily cemented near-prototype dunes were fabricated in the largest wave flume in North America at the O.H. Hinsdale Wave Research Laboratory at Oregon State University. Dunes were stabilized with two treatment application systems known as surface spraying and prefabricated vertical drains. Untreated and stabilized dunes were subjected to waves similar to Hurricane Sandy conditions recorded in New Jersey in 2012. Laboratory tests and in situ assessments were performed to quantify the improvement of mechanical properties of soil and investigate the performance of dunes subjected to extreme wave actions. Post-treatment cone penetration test sounding results indicated a significant cone tip resistance that was controlled by carbonate content and cementation distribution pattern. Similarly, monitoring the changes in the morphology of dunes demonstrated that the shear strength, cementation level, and cementation distribution pattern control the equilibrium beach profile, erosion rate, and mass loss.