JE Dunn completed the historic Pioneer Courthouse located in the heart of downtown Portland. Since the site covers an entire city block, access, public safety and traffic flow were critical issues. Pioneer Courthouse was originally built in 1875, long before seismic building codes. To update the building and make it seismically sound, JE Dunn installed a friction pendulum base isolation system. The friction pendulum base isolation system works by separating the building from the earth, in essence creating a dry moat around the building, detaching it from the ground at the perimeter. The isolation system allows the building to move freely from the earth up to 18 inches in each direction. All installation work happened underneath the building, preserving the historic fabric of the building. The courthouse is now able to withstand a subduction earthquake up to 8.5 magnitude, and the interior has been carefully refurbished to replicate its original characteristics.
