Objective - To develop next-generation methods and tools to better characterize coastal inundation hazards, associated loads, and response of structures, thus enabling performance-based standards for designing structures that resist coastal inundation.
What is the new technical idea? Current design requirements for coastal structures consider the effects of hurricane wind, wind-driven storm surge, and waves independently. In reality, wind, storm surge, and waves are coupled physical phenomena and their interdependency is site specific (the same wind intensity can generate different levels of storm surge and waves at different locations owing to the differences in local topography and bathymetry of these locations). Thus, to safely design for coastal structures in the U.S. that are exposed to the combined effects of hurricane wind, storm surge, and waves, it’s necessary to develop a set of risk-consistent design criteria that can take into account the variation of this combined hurricane hazard due to local topography and bathymetry. This project plans to use a novel, probabilistic, and interdisciplinary approach (wind, surge, waves, and structural engineering) to develop tools for (1) determination and quantification of site-specific coastal inundation hazards (wind loadings, hydrostatic pressure due to inundation levels, and design forces due to current velocity and debris impact loadings), (2) development of flood damage functions and fragility curves, and (3) establishment of performance levels and acceptance criteria for buildings subjected to the combined effects of hurricane hazards. These technical ideas support topics that have all been independently identified by the professional community in the new Measurement Science R&D Roadmap for Windstorm and Coastal Inundation Impact Reduction (Recommended Windstorm and Coastal Inundation Hazard Reduction R&D Topics, NIST 2014) as being high priority.
What is the research plan? NIST has conducted a proof-of-concept study and published - jointly with NOAA NWS, NOAA AOR (see Phan et al., Methodology for Development of Design Criteria for Joint Hurricane Wind Speed and Storm Surge Events: Proof of Concept, NIST TN 1482), and the University of Florida (Phan et al., Introduction of Wave Set-Up Effects and Mass Flux to the Sea, Lake, and Overland Surges from Hurricanes (SLOSH) Model, NISTIR 7689) – a pilot methodology for estimating hurricane risk to a pilot region in Florida. The research plan is to expand the applicability of this methodology to all coastal regions of the U.S. that are affected by hurricanes (Atlantic and Gulf Coast regions) to enhance the resilience of structures in these regions to hurricane hazards. To enable this expansion, we will (1) investigate the availability and accessibility of simulated storm surge data in new storm surge databases developed by NOAA and USACE, or any other new storm surge databases developed in recent years by private entities, for the entire Atlantic and Gulf Coast regions; (2) develop software, GIS-based tools that build on the NIST-developed methodology mentioned above, for data mining the storm surge databases to compute the site specific joint hazard (wind, storm surge, and waves) probabilities; and (3) develop methodology to use the computed site specific hazard probabilities to create site specific load combinations for designing coast structures exposed to hurricane hazards.
Phan, Long T.; Slinn, D.N.; Kline, S.; “Wave Effects on Hurricane Storm Surge Simulation,” ATC-SEI Advances in Hurricane Engineering Conference – Learning from Our Past, October 23-26, 2012, Miami.
Phan, Long T. and Simiu, E.; “Estimation of risk for design of structures exposed to combined effects of hurricane wind speed and storm surge hazards,” ICASP11, Applications of Statistics and Probability in Civil Engineering, Faber, Köhler, and Nishijima (eds), Taylor & Francis Group, London, ISBN 978-0-415-66986-3, August 2011.
Phan, Long T.; Slinn, Donald; Kline, Shaun; “Introduction of Wave Set-up Effects and Mass Flux to the Sea, Lake, and Overland Surges from Hurricanes (SLOSH) Model,” NISTIR 7689, May 2010.
Phan et al., Methodology for Development of Design Criteria for Joint Hurricane Wind Speed and Storm Surge Events: Proof of Concept; NIST TN 1482, National Institute of Standards and Technology, April 2007.