Kenneth J. Fridley

Simulation Management Systems Developed by the Northern Gulf Coastal Hazards Collaboratory (NG-CHC): An Overview of Cyberinfrastructure to Support the Coastal Modeling Community in the Gulf of Mexico

Given the significance of natural and built assets of the Gulf of Mexico region, the three states of Alabama, Louisiana, and Mississippi, leveraged their unique partnerships, proximity, and significant prior investments in cyberinfrastructure (CI) to develop the Northern Gulf Coastal Hazards Collaboratory (NG-CHC). This collaboratory was established to catalyze collaborative research via enhanced CI to reduce the regions vulnerability to natural and human disasters by facilitating high performance modeling to test hypotheses focused on engineering design, coastal system response, and risk management of coastal hazards. The objective of the NG-CHC is to advance research and inspire collaboration through highly available innovation-enabling CI, with a particular focus on geosciences and engineering from the watershed to the coast. An integrated CI capable of simulating all relevant interacting processes is needed to implement a system that captures the dynamic nature of coastal surface processes. The NG-CHC has implemented CI to locate appropriate data and computational resources, create necessary workflows associated with different simulation demands, and provide visualization tools for analysis of results. Three simulation management systems, SIMULOCEAN, SULIS, and ASGS, were implemented, each with a defined suite of hypotheses and institutional participants to run collaborator experiments. The NG-CHC focused on developing suites of CI tools centered on handling the functional needs of each simulation management system in a collaborative environment. The NG-CHC also developed curriculum units, computer games and simulations to extend the knowledge of coastal hazards to students from middle school to college. Education and outreach activities were developed to increase public understanding and support for sustainable coastal practices. The elements of the CI tool box within NG-CHC describe generic tools needed to promote a ‘collaborative modeling environment’ in other coastal systems.

Overview of Wind Damage to Woodframe Structure Caused by Hurricane Katrina

Hurricane Katrina, the most costly natural disasters in U.S. history, made landfall on August 29, 2005 at 7:10 a.m. local time in Plaquemines Parish, LA. Although Katrina caused widespread damage and loss of life, it also provided an opportunity to evaluate how woodframe construction performed in a naturally occurring high wind speed environment. A team of researches from across the country, sponsored by the National Science Foundation, conducted a three day study that investigated 27 sites containing woodframe structures along the Gulf Coast of Mississippi. Sites included entire subdivisions, light commercial structures, multifamily apartment buildings, and singe family homes. Observed wind induced damage at these sites included the loss of a few shingles, loss roof sheathing, loss of siding or brick veneers, porch collapses, roof loss, and also woodframe building collapse. The goal of this study was to examine wind damage in detail, determine the failure mechanisms when ever possible, and provide recommendations for individuals and organizations involved in the woodframe structure industry. Results of this investigation indicated that woodframe residential and light commercial structures that followed design codes and guidelines performed well during hurricane Katrina’s wind loading. It appeared that builders and inspectors were familiar with conventional construction provisions; however, these provisions were used erroneously at times in this high wind region along the Gulf Coast. Where failures occurred, careful attention was not paid to all details, particularly the (correct) use of all straps and ties, to ensure a continuous load path from the roof to the foundation. It was observed that architectural shingles tended to remain intact more often that regular roof shingles and a closer/heavier nailing schedule for roof sheathing would reduce the amount of roof sheathing loss. Seemingly insignificant details such as the proper connection of non-structural siding resulted in the loss of siding followed by the loss of