Coastal Inundation: Hazard Characterization and Structural Design

Summary

The project develops next-generation procedures for achieving designs that are safe, sustainable, and economical under coastal inundation, consistent with priorities described in the Measurement Science R&D Roadmap for Windstorm and Coastal Inundation Impact Reduction (NIST 2014). It supports these procedures with novel tools for accurate characterization of coastal flood hazards and structural response to the effects of these hazards. These tools include modern probabilistic and statistical methods to conduct location-specific probabilistic assessments of the combined effects of hurricane wind, storm surge, and wave hazards using hurricane and storm surge databases.

Description

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.

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REFERENCE DOCUMENTS:

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.

Major Accomplishments

Research Outcomes:

• Habte, Filmon; Chowdhury, Arindam; Yeo, Dong H. ; Simiu, Emil; "Wind directionality factors for non-hurricane and hurricane-prone regions", J. Struct. Eng. in review.
• Simiu, Emil; Fu, Tuan-Chun ; Gan Chowdhury, Arindam;Smith, Douglas; Zisis, Ioannis; Irwin, Peter; (2014) "Experimental investigation of wind pressures on large-scale building models and comparisons with field measurements", J. Struct. Eng. in review.
• Simiu, Emil; Habte, Filmon; Gan Chowdhury, Arindam; (2014). " Data volume reduction for aerodynamic testing and structural design", Wind and Structures, in review.
• Kuligowski, Erica D.; Lombardo, Franklin T.; Phan, Long T.; Levitan, Marc L.; Jorgensen, David P., (2013). "Technical Investigation of the May 22, 2011, Tornado in Joplin, Missouri: Darft Final Report." NIST NCSTAR 3 (Draft for Public Comment).
• Yeo, D. (2013). "Generation of Large Directional Wind Speed Datasets for Estimation of Wind Effects with Long Return Periods", Journal of Structural Engineering, ASCE, in review.
• Dunn, C.L., Friedland, C.J., and Levitan, M.L., (2013). "Statistical representation of design parameters for hurricane risk reduction of structures", Structural Safety, in review.
• Kuligowski, Erica D.; Lombardo, Franklin T.; Phan, Long T.; Levitan, Marc L.; Jorgensen, David P., (2013). "Technical Investigation of the May 22, 2011, Tornado in Joplin, Missouri: Draft Final Report." NIST NCSTAR 3 (Draft for Public Comment),

Potential Research Impacts:

• Yeo, D. (2014). "Generation of Large Directional Wind Speed Data Sets for Estimation of Wind Effects with Long Return Periods." J. Struct. Eng.
• Gabbai, R. and Simiu, F., (2013). "Evaluation of Mean Recurrence Intervals of Wind Effects for Tall Building Design", Journal of Structural Engineering, ASCE, in press.
• Simiu, E., Letchford, C., Isyumov, N., Chowdhury, A.G., and Yeo, D, (2013). "An Assessment of ASCE 7-10 Standard Methods for Determining Wind Loads", Journal of Structural Engineering, ASCE, in press.
• Yeo, D. and Potra, F., (2013). "Sustainable Design of Reinforced Concrete Structures through CO2 Emission Optimization", Journal of Structural Engineering, ASCE.
• Yeo, D., Lin, N., and Simiu, E. (2013). "Estimation of Hurricane Wind Speed Probabilities: Application to New York City and Other Coastal Locations," Journal of Structural Engineering, ASCE.
• Hagos, A., Habte, F., Chowdhury, A., and Yeo, D. (2014). "Comparisons of Two Wind Tunnel Pressure Databases and Partial Validation against Full-Scale Measurements." J. Struct. Eng. , 10.1061/(ASCE)ST.1943-541X.0001001 , 04014065.

Realized Research Impacts:

• Gabbai, R. and Simiu, E. (2014). "Evaluation of Mean Recurrence Intervals of Wind Effects for Tall Building Design." J. Struct. Eng., 140(1), 04013037.
• Published Final Report - National Institute of Standards and Technology (NIST) Technical Investigation of the May 22, 2011, Tornado in Joplin Missouri.
• Kuligowski, Erica, Phan, Long, Levitan, Marc, Jorgensen, David (2013) Preliminary Reconnaissance of the May 20, 2013, Newcastle-Moore Tornado in Oklahoma, NIST SP 1164.
• Simiu, E., Letchford, C., Isyumov, N., Chowdhury, A., and Yeo, D. (2013). "Assessment of ASCE 7-10 Standard Methods for Determining Wind Loads." J. Struct. Eng., 139(11), 2044–2047.
• Yeo, D., Lin, N., and Simiu, E. (2014). "Estimation of Hurricane Wind Speed Probabilities: Application to New York City and Other Coastal Locations." J. Struct. Eng., 140(6), 04014017.
• Yeo, D., (2013). "Multiple Points in Time Estimation of Peak Wind Effects on Structures", Journal of Structural Engineering, ASCE, 139, 462-471.
• Fu, T.C., Aly, A.M., Chowdhury, A.G., Bitsuamlak, G., Yeo, D. and Simiu, E. (2012). "A Proposed Technique for Determining Aerodynamic Pressures on Residential Structures," Wind and Structures, 15 (1).
• Lombardo, F.T., (2012). "Improved extreme wind speed estimation for wind engineering applications," Journal of Wind Engineering and Industrial Aerodynamics, Volumes 104–106, Pages 278–284.
• Yeo, D. and Simiu, E., "High-Rise Reinforced Concrete Structures: Database-Assisted Design for Wind," Journal of Structural Engineering, ASCE.
• Crosti, C., Duthinh, D., and Simiu, E., "Risk-consistency and synergy in multi-hazard design," Journal of Structural Engineering, ASCE.
• Coffman, B., Main, J., Duthinh, D., and Simiu, E., (2010). "Wind Effects on Low-Rise Metal Buildings: Database-Assisted Design vs. ASCE 7-05 Standard Estimates," Journal of Structural Engineering, ASCE.
• Duthinh, D., and Simiu, E., (2010). "Safety of Structures in Strong Winds and Earthquakes: Multihazard Considerations," Journal of Structural Engineering, ASCE.
• Simiu, E., Gabbai, R.D., Fritz, W.P., "Wind-induced tall building response: a time domain approach," Wind and Structures, 11, 427-440.
• Lombardo, F.T., Main, J.A., and Simiu, E. (2009) "Automated Extraction and Classification of Thunderstorm and Non-Thunderstorm Wind Data for Extreme-Value Analysis," Journal of Wind Engineering and Industrial Aerodynamics, 97(3-4), 120-131.
• Fritz, W.P., B. Bienkiewicz, B. Cui, O. Flamand, T. C. E. Ho, H. Kikitsu, C. W. Letchford, and E. Simiu , "International Comparison of Wind Tunnel Estimates of Wind Effects on Low-Rise Buildings: Test-Related Uncertainties," Journal of Structural Engineering, ASCE, 134 87-90.

Impact of Standards and Tools:

• Proposals submitted to the ASCE 7 Standard on combined wind and storm surge, combined wind and seismic loads, database assisted design, and the wind tunnel method. (FY13)
• New hurricane shelter design wind speed map submitted to and accepted by the ICC 500 Storm Shelter Standard committee. Updated draft standard will be released for public comment soon. (FY13)
• Database Assisted Design for Tall Reinforced Concrete Buildings software tools. (Posted online in FY11)
• Technical Basis for Regulatory Guidance on Design-Basis Hurricane-Borne Missile Speeds for Nuclear Power Plants, issued as NUREG/CR-7004, U.S. Nuclear Regulatory Commission. (Published in FY12)