Collaborative Research: Hybrid Flow-Sediment-Structure Interaction Analysis of Extreme Scour due to Coastal Flooding

Foundation scour is one of the primary causes of structural damage in coastal communities during flooding events. This project will leverage state-of-the-art in wave flume physical modeling, geotechnical centrifuge modeling, and numerical simulation to answer a number of critical and open questions related to the interactions among extreme flood flow, soil, and structure which lead to scour and foundation failure—shifting the paradigm in the current understanding of key physical processes in flood-induced scouring process in complex urban setting.

Enhancement of open-source multi-physics computational tool for coastal hazard mitigation will provide a strong multi-disciplinary modeling platform to the broader civil and coastal engineering research community. The new parameterization set for extreme scour-liquefaction resulted from the fundamental knowledge-gain will benefit region-scale nearshore morphodynamic modeling and the state of foundation design in flood-prone areas.

The education and outreach efforts will broaden the participation at all levels including: (1) recruitment, retention, and education of underrepresented students in three collaborating institutions; (2) engaging science teachers in three coastal states with different urban settings and population, in coastal infrastructure and community resiliency training; and (3) enhancing the well-being of the coastal residents through changing the design and hazard mitigation protocols.

This project will bridge the state-of-the-art in sediment transport and scour, unsaturated and saturated soil mechanics, and hydrodynamics of flood flow. This goal will be achieved by correlating the spatiotemporal variations of scouring and loading with the dynamics of shallow flood flows within complex urban setting and water hysteresis in unsaturated soils around and underneath surface structures.

The research objectives of this project are to understand: (1) scouring patterns of single and array of structures, under various flow and soil states; (2) initiation and progression of foundation scouring in low fines content soils of varying properties (i.e., composition, relative density, initial water content); (3) soil-foundation interaction response under simultaneous wave action and hydraulically-induced excess pore pressure; (4) rocking response of shallow foundations in unsaturated ground; (5) enhancement of an open-source Eulerian two-phase modeling framework for a complete description of seabed stability and scour; and (6) incorporating an extended effective stress-based sub-model and a revised solver for slight water compressibility to simulate soil behavior in partially drained and unsaturated condition with high overburden. The long-term goal of this project is to create public-domain tools for reliable scour predictions of complex urban and non-urban settings, under extreme coastal flooding conditions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.