Many older buildings provide vital, low-cost housing. But we must find a way to make these structures safer. It should not be acceptable to us to subject our fellow citizens to such hazardous conditions.
ONCE again we are reminded of the deadly potential of powerful earthquakes. We are confronted by images from Mexico of collapsed buildings, volunteers searching the rubble for survivors and parents facing their worst nightmare.
As earthquake engineers, we see the failure to address the well-known vulnerabilities of older, brick buildings (unreinforced masonry) and brittle reinforced concrete construction. These heavy and brittle older buildings lack the strength and details necessary to prevent collapse in large earthquakes. The images from Mexico also remind us of society’s responsibility to protect its most vulnerable members, including children and those without the economic resources to improve the safety of the buildings in which they live.
The situation in Washington state is not identical to that in Mexico, but the parallels are too glaring to ignore. Western Washington has a number of sources of potential earthquakes, including the Cascadia Subduction Zone and the Seattle Fault, which combine to create a serious regional seismic hazard. The Puget Sound region has local soil and geologic conditions that can amplify earthquake ground motions. We also know that the city of Seattle has identified more than 1,000 unreinforced masonry buildings within its city limits, and Washington state undoubtedly has thousands more. Our state has well-known vulnerabilities in our hospital, highway, port and utility facilities, and it has a large but unknown number of older reinforced concrete buildings. Perhaps most dangerously, we live in a region in which there are no regular reminders of the seismic hazard. Complacency is easy when the task is to mitigate catastrophic but infrequent disasters.
Our region is making progress in some areas. New buildings and bridges are designed for much stronger earthquake ground motions than older ones. Seattle Public Schools has addressed critical hazards in many of its buildings, and the City Council is considering a policy to mandate the seismic retrofit of unreinforced masonry buildings. Many lifeline organizations have identified their main vulnerabilities, and the extremely vulnerable Alaskan Way Viaduct will soon disappear. The Resilient Washington Subcabinet Report documents other accomplishments, and it recommends numerous further planning activities.
These activities are welcome, but for too long we have been postponing making the investments needed to decrease the largest risks facing our people and economy. Earthquakes are inevitable in Western Washington, but catastrophic consequences are not. We need to address these priorities:
• Let’s address the well-known hazards of older brick and concrete buildings. We understand that there are social and political challenges to solving this problem in a region with a housing affordability crisis. Many older buildings provide vital, low-cost housing. But we must find a way to make these structures safer in a way that is sustainable and fair. It should not be acceptable to us to subject our fellow citizens to such hazardous conditions.
• Let’s ensure that all schools in Washington state are not only evaluated for seismic hazards but also that the conditions that threaten life are mitigated.
• Let’s ensure that hospitals and other critical facilities will remain operational to serve the community in the critical hours and days following a large earthquake.
• Let’s ensure our most critical transportation and utility lifelines will function soon after an earthquake. Our long-term prosperity depends on it.
These actions will not be easy. They will require a serious commitment by us and our political leadership to create a safer and more resilient Washington.