Blast and Impact Loading and Response of Structures
Full Session with Abstracts
While international terrorist organizations have been active across the globe for decades, attacks against public surface transportation infrastructure have been a growing concern. As a result, considerable research has been carried out in the area of bridge security over the past decade. Important advancements have been made in the areas of vulnerability assessment and risk-based prioritization methods, component-level blast load characterization, dynamic response analysis procedures, and blast threat mitigation techniques. Although much research is still needed, it is important to begin transferring these state-of-the-art protective design concepts and methodologies to the appropriate users within the bridge community. As such, an essential next step in enhancing the security of public highway bridges is to synthesize this newly developed protective design technology into an expedient and user-friendly engineering tool capable of facilitating effective anti-terrorist/force protection (ATFP) retrofits of current bridges and safe designs of new bridges. Such a tool would enable practicing bridge engineers to implement essential blast-resistant analysis and design strategies without having to rely on time-consuming, costly, and complex resources such as physical testing or high-fidelity computational modeling.
Anti-Terrorist Planner for Bridges (ATP-Bridge) has been developed to specifically address these highway infrastructure security issues and, more generally, to help facilitate the implementation of research findings into current practice. The ATP-Bridge software is a companion tool to the newly published FHWA Bridge Security Design Manual and is currently in its third version. ATP-Bridge is a practical engineering-level software program capable of predicting the response and incurred damage of critical bridge components subjected to a variety of threat scenarios. The software relies on fast-running computational algorithms that have been validated against available experimental data. The current version of ATP-Bridge (Version 3) encompasses component response models for reinforced concrete (RC) bridge columns, steel suspension bridge tower panels, RC bridge tower panels, and high-strength steel cables. With regard to threat scenarios, the software is capable of considering contact and near-contact high-explosive charges, standoff detonations from bulk high-explosive threats, and various thermal, mechanical, and explosive cutting threats. ATP-Bridge is intended to be utilized primarily by bridge engineers and vulnerability assessment personnel, but it can also be used by emergency responders and law enforcement professionals to help quantify the likelihood of a major transportation disruption as a result of a postulated malicious attack. This information can then be used to support emergency planning decisions such as critical resource allocation.