Blast and Impact Loading and Response of Structures
Full Session with Abstracts
While previous infrastructure security research and practice have focused primarily on building structures, recent worldwide statistics indicate a trend of increasing attacks against public transportation assets, with highway infrastructure being among the most frequently targeted. Public highway bridges are highly accessible, and, unlike typical building structures, they often lack the level of structural redundancy and exterior envelope protection needed to adequately withstand the extensive localized damage likely to result from a nearby explosion. Furthermore, the limited amount of bridge-specific protective design guidance in today’s engineering guidelines and specifications suggests that the nation’s existing highway bridges may not be well protected against large-scale terrorist attacks and anti-terrorist/force protection (ATFP) concepts are not being incorporated into new highway bridge construction. As evidenced by recent non-terrorist-related bridge collapses around the nation, the sudden failure of a highway bridge located on a major transportation corridor has the potential to cause significant economic loss, human casualties, and societal distress. From a national defense perspective, the U.S. military relies heavily on the public highway system (e.g., STRAHNET) for moving military equipment and personnel from military installations to various seaports and airports around the country.
To begin to address this concern, the U.S. Federal Highway Administration (FHWA) organized and led an initiative to collate the current state-of-the-art in bridge security into an industry standard guidance document—The FHWA Bridge Security Design Manual. The primary objective of this bridge security design manual is to present state-of-the-art guidance on bridge-specific security planning, extreme loading phenomenology and characterization, and protective design strategies to be used by the highway bridge community in terrorist threat vulnerability assessments of existing bridges, resilient design of new bridge construction, and emergency planning efforts. When compared to the amount of knowledge and formal guidance that currently exists for security and protective design of critical building structures, bridge security in the U.S. is in a relative stage of infancy. As such, bridge security will continue to be an active area of research and development for years to come, and this manual will be updated and expanded accordingly to remain a comprehensive, state-of-the-art reference for the highway bridge community.