The onshore damage caused by Hurricane Katrina is self-evident and fundamental mechanisms can be readily studied. However, offshore damage is often unknown, and even when its effects are evident above water - as in the case of collapsed bridge segments - the underlying processes that are the result of sediment-structure-storm interaction cannot be properly analyzed in the absence of offshore data. This project will use sonar/sub-bottom profiler imaging of the sediment-water interface and subsurface layers to gain unprecedented insight into sediment transport and sediment-system interaction near bridge foundations, piping, anchors, walls and embankments, erosion and redeposited sediments. This information can then be used use to identify and assess offshore failure mechanisms during storms. The successful completion of the proposal will provide basic offshore data to help developing the following broader impacts: o generation of analytical and numerical simulations of sediment-structure-storm interaction by researchers in various fields, from geomechanicians and sedimentologists, to port and bridge engineers and geophysicists; o dissemination to other researchers, the PIs will make the data available through their websites; o documentation of data in teaching modules to be made available to the geotechnical community through USUCGER; o implementation/analysis of data in PIs' courses that include soil behavior, applied geophysics, signal processing, inverse problems, and wave propagation, both at the University of Wisconsin-Madison and at Georgia Tech.
