Seismic risk to the charleston, SC transportation network

Earthquakes pose a considerable threat to lifeline systems in regions of high or moderate seismicity, such as Charleston, SC. In particular, in areas such as Charleston, where the last significant earthquake occurred over 120 years ago, most of the existing transportation facilities were designed with little to no seismic consideration. However, a growing public awareness of the seismic threat has motivated an assessment of the potential risk to the transportation network to support decision-making on mitigation strategies and emergency planning and preparedness efforts, such as emergency route (lifeline) selection. This paper presents the findings of the first phase of the project, which applies the seismic risk assessment framework with state-of-the-art tools and relevant data specific to the region of interest. This includes an inventory analysis of the roughly 340 bridges in Charleston County, and convolution of the seismic hazard with fragility curves analytically derived for classes of bridges common to this part of the country, and bridge damage-functionality relationships using region-specific data. The study includes assessment and comparison of the distribution of bridge damage for a number of different hazard levels or scenario events. The potential bridge functionality is also presented to aid in identification of emergency routes. The results provide insight for decision-makers as to the potential seismic risk to the transportation network in Charleston, and identification of emergency routes or regions in need of strengthening.