Real-time structural instrumentation as an emergency response and business continuity tool

Abstract

Structures worldwide have been instrumented with sensor systems (vibration accelerometers, strong-motion sensors, strain gauges, etc.) for the purpose of recording structural response data. Researchers, structural engineers, and seismologists use these data to further our understanding of actual building dynamic behavior and validate theories that lead to building code improvements. These same structural health monitoring (SHM) and instrumentation systems can also be utilized to report on the post-earthquake or disaster status of infrastructure to benefit building owners and public safety. First-hand experience from post-earthquake response efforts has indicated that the decisions to evacuate and reoccupy are difficult, especially under a state-of-emergency. These decisions can have dire consequences such as panic related injuries, lack of facility use, and significant financial and potential life loss due to unnecessary post-disaster closures and downtime. These potential consequences are heightened for essential facilities such as hospitals and emergency response facilities. Although the concept of using strong-motion instrumentation to directly benefit the building owner has been discussed in the SHM community, a real, marketable solution built upon strong-motion monitoring, performance-based earthquake engineering principles, and standard-of-care post-disaster assessment protocols has yet to be put into practice until now. The real-time SHM systems of strong-motion accelerometers measure the acceleration at several levels/locations in a building, perform real-time double integration to calculate building displacements and drifts, and compare building drifts with pre-defined drift thresholds. The system utilizes intuitive onsite display, alerting, reporting, and remote notification tools to communicate results to building owners and facility managers throughout all phases of the post-earthquake response, inspection, and recovery process. Several case studies are presented describing how post-disaster real-time strong-motion instrumentation systems have been deployed in commercial applications for essential facilities to provide building owners and managers with real-time information to make knowledgeable decisions. This will improve disaster preparedness, the safety of building occupants, and ultimately the resiliency of communities.