Object Burial by High-Energy Forcing: Liquefaction and Granular Sorting
Abstract
This review and status report is focused on the potential for burial or possible exhumation of unexploded ordnance (UXO1) and marine munitions in sandy coastal areas by high energy wave forcing. Several processes for UXO burial have been included in the Underwater Munitions Expert System (UnMES), most notably burial by scour. Some evidence suggests that, in the nearshore and surf zone, high energy waves could also drive burial by liquefaction or by granular sorting. These mechanisms have been reviewed for inclusion in UnMES as process models. It has been found that the extant literature on the behavior of isolated objects, relevant to munitions burial, by these mechanisms is highly limited. While studies of the behavior of coastal structures, e.g. pipelines, breakwaters, under liquefaction can be extrapolated to objects, validation of such extrapolations is limited, and they lack general applicability to sandy sediments. The main objective of this report is to determine whether a new liquefaction model should be included in the current version of UnMES which is focused on sandy environments. Currently funded SERDP MR efforts are designed to address high-energy burial mechanisms; however, at present these studies are still in progress. As a result, there remains an insufficient level of understanding, as well as a lack of adequate data to justify inclusion of these processes in UnMES. Thus, the decision to not include new physics-based liquefaction and granular sorting models in the expert system at this time is appropriate( a NO-GO decision). For research purposes however, a simplified liquefaction burial model, discussed in this report, is currently implemented in UnMES as a preliminary, exploratory tool. At some future time, with increased knowledge and data, a validated model for high-energy burial in non-cohesive sediment would be an important addition to UnMES.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 31, 2021
- Accession Number
- AD1219174
Entities
People
- Alan Brandt
- Sarah E. Rennie
Organizations
- Johns Hopkins University