New Research to Inform Earthquake Design of Tall Buildings

On Thursday, March 22, SDCI and the US Geological Survey (USGS) hosted a workshop to determine how to account for higher earthquake motions due to the Seattle Basin and the Cascadia Subduction Zone when designing tall buildings (over 240 feet). The invited workshop participants included some of the premier seismologists in the country, researchers from the UW working on the M9 project ( , local geotechnical and structural engineers from the consulting community and the City of Bellevue, and SDCI staff. The workshop participants spent a full day reviewing current geotechnical seismic practice, presenting recent research on measured and calculated models of seismic basin response, learning about the effect of higher earthquake motions on structural design practice, and developing a consensus for the short term and longer term. This workshop is a follow-up to a workshop hosted by SDCI and the USGS in 2013 (

The consensus recommendations will slightly increase the earthquake forces for which tall buildings are designed in Seattle. The lead USGS seismologist said after the meeting that this is the only place in the country where researchers from academia, practicing engineers, and city government come together to understand each other’s perspectives and to develop solutions considering recent research for safer building design.

For more information, contact:

Susan Chang
Seattle Department of Construction and Inspections