Preliminary Simulations of Free-Fall Penetrometer Behavior: Toward Validating against Geotechnical Field and Laboratory Observations and Predicting Sediment Erosion and Deposition in Waterways in Coastal Louisiana

摘要

Sediment instability and erosion in coastal wetlands has been identified as a major concern, particularly in locations such as coastal Louisiana. In order to model coastal zones, an improved understanding of sediment transport, erodibility, and morphologic evolution is crucial. The geotechnical sediment behavior in areas of active sediment dynamics is still poorly understood, and rarely integrated in predictive models. During field investigations at three locations in coastal Louisiana, loose and likely mobile sediment surface layers were characterized using a free fall penetrometer. The predictive capabilities of numerical tools need to be validated against datasets from such investigations, before numerically investigating the evolution of mobile layers, their geotechnical characteristics and the resulting potential impact on increasing sediment erodibility during extreme events. In this paper, a brief literature review is presented on current methodologies of numerical simulations of field testing processes. Preliminary results from a three-dimensional simulation in finite difference platform of the field-testing method at a generic soil profile are presented in order to evaluate current capabilities and limitations of numerical platforms and protocols. Areas of future research are identified and a discussion is presented on the prioritized fronts.