Modeling Munitions Mobility and Burial in a Micro-Tidal Estuary
Abstract
The study of underwater unexploded ordnances (UXOs) mobility and burial in underwater environment is of paramount importance due to the large number of sites potentially contaminated with munitions. This project, called MINELAB, aimed at modeling the fate of munitions displaced over or buried into the heterogenous sedimentary bed of a micro-tidal estuarine site, subjected to both fluvial and marine forcing. The objective was twofold: (1) to directly observe the combined effect of river flow, water waves and tide on the mobility and burial of UXOs; (2) to predict the behavior of UXOs subjected to the combined action of river discharge and waves in a micro-tidal environment characterized by mixed sediments. Results of field tests showed that UXOs deployed in areas characterized by different soil material behave differently. Once placed on the muddy riverbed, the UXOs almost instantaneously got buried and did not move. Just the smallest and least dense UXO showed some migration and resurfaced at times. On the other hand, the UXOs remained proud on the sandy seabed, until a wave storm produced a significant morphological seabed evolution, likely fostered by fluidization of the sandy bed, that caused their complete burial. The largest observed migration distances were of the order of 7 m. The Underwater Munitions Expert System (UnMES) simulation, aiming at reproducing the UXOs behavior during the field test performed at sea, showed a migration distance in the range 0m to 5m, in agreement with the observations. Predicted burial depths were, instead, smaller (50 percent to 75 percent of the UXO diameter) than those observed in the field (over 100% of the UXO diameter).
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 2024
- Accession Number
- AD1229791
Entities
People
- Agnese Baldoni
- Francesco Marini
- Lorenzo Melito
- Matteo Postacchini
- Maurizio Brocchini
Organizations
- Polytechnic University of the Marches