Supplemental Materials 2026-01-28

The Oregon Resilience Plan – Critical and Essential Buildings – February 2013 83 The building stock of Oregon’s K-12 schools possesses seismic vulnerabilities that are common to the specific building types of which it consists. Unreinforced masonry (URM) buildings historically perform poorly in seismic events and are the most dangerous existing building type in the school building stock (See Figure 4.5). Many 1930s-era multistory schools rely on lightly-reinforced concrete shear walls that are historically poor performers as well. Wood framed schools should perform well provided they are well constructed, even though many of them pre-date building codes. These wood buildings may possess deficiencies, including weak or missing roof-to-wall connections, and weak or missing anchorage of walls to foundations—all of which could contribute to poor seismic performance. Concrete tilt-up buildings have also proven to perform poorly in earthquakes. Newer tilt-up buildings have been improved by code changes adopted following the 1994 Northridge earthquake in California, but older tilt-up buildings, and even CMU buildings, may remain vulnerable due to poor connections between heavy rigid walls and flexible roofs. Modular classrooms may also be vulnerable, because they may have insufficient connections to their foundations. In addition, many schools contain unsecured and inadequately braced nonstructural components that may present falling hazards during a seismic event (See Figure 4.6). Figure 4.6: Pendant light fixtures failed in this elementary school library during the 1983 M6.5 Coalinga, California earthquake. If the room had been occupied, this could have caused injuries. Bracing nonstructural elements in homes, schools, and offices can often be done easily and relatively inexpensively. (Source: NOAA/NGDC, Earthquake Engineering Research Institute)