Seismic Screening of Public Facilities in Oregon’s Western Counties

The objective of this study was to use rapid visual screening (RVS) methods to identify potential seismic hazards for Oregon’s public facilities, including schools, hospitals, fire stations, police stations, and emergency response centers. There were 1,075 buildings screened in nine western Oregon counties. This study is part of a larger effort under the 2005 Oregon Senate Bill 2 to assess the seismic needs and upgrade public facilities in Oregon. RVS methodology generally followed FEMA 154 Rapid Visual Screening of Buildings for Potential Hazards: A Handbook. This method identifies structural type and building characteristics that may indicate poor performance under the maximum considered earthquake (MCE). Each building is given a final score related to the probability of collapse under the MCE. Screening was conducted by four individuals over three months. Quality assurance (QA) testing on nine buildings examined consistency between screeners. QA results showed final scores varied between screeners depending on building size, structure type, and architectural cladding. FEMA 154 was developed using California buildings. Differences between Oregon and California construction and the use of FEMA 154 in Oregon are discussed in this paper, reviewing the Uniform Building Code (UBC) and Oregon Structural Specialty Code (OSSC) amendments. The study provided two important conclusions. First, the average final score for buildings screened fell below the FEMA 154 cut-off score of $2.0\text{Second}$ , the OSSC had an exception to the UBC that allowed the construction of unreinforced masonry buildings two stories or less in height. With this context, screening results can help in assigning priorities for further analysis and seismic retrofits.