Unreinforced Masonry Seismic Study

  • Location Seattle, WA
  • Client City of Seattle
  • Understanding Unreinforced Masonry

    Seismic screening of URMs in Seattle to understand earthquake risk.

Reinforcing the need to retrofit URMs. The City of Seattle wished to better understand the seismic hazard associated with Unreinforced Masonry buildings (URMs) within the city limits, which house numerous businesses, residents, and patrons. Reid Middleton completed an in-depth study of Seattle’s URM population, which will be used by the city to develop a risk mitigation strategy, possibly mandating retrofitting of high-risk URMs. We compiled existing data related to URM from past FEMA 154 Rapid visual Screening efforts the city had completed, and then Reid Middleton performed FEMA 154 screening of 450 URMs in several neighborhoods. The gathered data was used to estimate the overall URM population and identify areas of highest risk based on soil conditions, seismicity, and screening results. Then, we researched retrofit mandates formed by other cities.