Mobility of unexploded ordnance using spherical surrogates in the swash zone
| Author(s) | Gross, Benedict M. | |
| Date Accessioned | 2020-02-27T12:29:05Z | |
| Date Available | 2020-02-27T12:29:05Z | |
| Publication Date | 2019 | |
| SWORD Update | 2020-02-03T13:29:54Z | |
| Abstract | Predictive and probabilistic models require physical data to implement a practical procedure for monitoring and removing munitions or unexploded ordnance (UXO). Physical UXO response to wave forcing varies depending on the shape, location and density of a given munition. A laboratory experiment was conducted to study the mobility of spherical munition surrogates for cluster bombs (BLU61). ☐ A dam-break mechanism was designed in the Center for Applied Coastal Research wave flume, generating repeatable swash events onto a mobile sand bed with median grain diameter of 0.31 mm and a slope of 1:7. A variety of sensors were deployed in the flume to monitor the produced hydrodynamics including a maximum water velocity ~ 1.5 m/s. A Velodyne laser system was used to monitor bed surface variability. A wide-angle field of view camera was deployed from overhead to track surrogate response in the form of displacement. ☐ Four spherical munition surrogates were constructed to span a range of densities (specific gravity between 1.8 and 7.7). Surrogates were deployed in pairs at five different locations on the beach and at three different burial depths. Each scenario was repeated five times to determine a probabilistic response to repeatable forcing, determined by sensor data comparison for all runs. The beach was reshaped manually between subsequent runs, and a root-mean-square elevation error of less than 3 mm was maintained. Imagery from the overhead camera was converted to real world coordinates through a camera calibration and rectification. Cross-shore surrogate trajectories were traced using a motion-based object tracking technique and validated through manual measurements. ☐ A relationship between wave forcing, initial sphere location, initial burial depth and sphere density to sphere response (subsequent migration) was formed through parameterization and a dimensional analysis. An Object Mobility Number was identified for and compared to the total distance traveled determined from averaging five cross-shore trajectories (squared correlation coefficient of 0.65). Calculated mobility numbers increased with a decrease in density. Total travel distance decreased with an increased initial burial depth. Net onshore motion was not observed for any of the tested scenarios. Motion initiated upon uprush or backwash always resulted in a net offshore displacement. | en_US |
| Advisor | Puleo, Jack A. | |
| Degree | M.C.E. | |
| Department | University of Delaware, Department of Civil and Environmental Engineering | |
| DOI | https://doi.org/10.58088/cr3r-eb67 | |
| Unique Identifier | 1142098706 | |
| URL | http://udspace.udel.edu/handle/19716/25065 | |
| Language | en | |
| Publisher | University of Delaware | en_US |
| URI | https://search.proquest.com/docview/2307477131?accountid=10457 | |
| Title | Mobility of unexploded ordnance using spherical surrogates in the swash zone | en_US |
| Type | Thesis | en_US |