Seattle’s historic buildings may not have seen quite as much history as those in Boston or New York, but the city has devoted a great deal of effort in recent years to preserving structures built during the logging boom of the 1800s for future generations. The problem: many of these buildings are made of brick or other unreinforced masonry, and their builders didn’t have the same knowledge as modern architects about how to build a structure that won’t collapse in an earthquake. While modern buildings have steel reinforcement and structural connections to keep brick facades from crumbling and floors from pancaking in a quake, most brick buildings built prior to 1940 lack those necessary protections.
Add 100 years of erratic maintenance, an increasing body of scientific work about seismic risks, and a newfound awareness of the dangerous liquefaction zones in Seattle’s urban core, and it’s no wonder that city planners are worrying about how to keep residents safe in the event of the Big One. The most dangerous structures could crumble or even collapse during a big earthquake. According to estimates by a Seattle Times investigative team, more than 26,500 people are within the walls of unreinforced masonry structures at any given time. Apartment buildings, private homes, restaurants, workplaces, and even schools may be in danger of collapse in a quake.
The problem: while Washington state lawmakers have known about the dangers of unreinforced masonry structures for over 20 years, no law requires property owners to reinforce their hazardous buildings. The only way to pressure building owners to make those costly upgrades is to wait until them apply for a permit, then force them to make improvements.
Now, a new program by the Seattle Department of Construction and Inspections is cataloging unreinforced masonry structures in the city in the hopes of forcing landlords to update their buildings. In April of this year, they released a list of unreinforced buildings in need of structural updates. Now, they’re pushing harder for change, with discussions in the works at the state level.
“Public safety is the primary reason we’re proposing a mandatory retrofit program for URMs. … When a building is damaged, occupants in the building are in danger of injury. Debris from the damaged buildings often will block the adjacent sidewalks and roadways which delays emergency response and can prolong overall neighborhood recovery,” Bryan Stevens, media handler for the SDCI, told reporters.
Image: A van crushed by debris from a brick building after the 2001 Nisqually earthquake struck Seattle. This photograph was taken by photographer Kevin Galvin. Image source: Wikimedia Commons