October 2024

Pioneer Federal Courthouse

The Pioneer Courthouse, a historic gem that serves as the backdrop of Pioneer Courthouse Square, known as Portland’s living room, exemplifies JE Dunn’s exceptional expertise and commitment to preservation. Completed in collaboration with the General Services Administration (GSA), this project presented unique challenges due to its location, history, and the need for seismic upgrades. Originally built in 1875, the Pioneer Courthouse predates modern seismic building codes, necessitating significant updates to ensure its safety and longevity.

The courthouse covers an entire city block, making access, public safety, and traffic flow critical considerations throughout the project. JE Dunn approached these challenges with precision, ensuring minimal disruption to the surrounding community. The solution to the seismic concerns was both innovative and complex: the installation of a friction pendulum base isolation system. This system essentially creates a dry moat around the building, detaching it from the ground and allowing it to move freely up to 18 inches in any direction during an earthquake. This upgrade enables the courthouse to withstand a subduction earthquake of up to 8.5 magnitude, significantly enhancing its resilience.

JE Dunn’s Darin Stegemoller, who has a rich history of working on similar projects, shared insights into the complexities and triumphs of the Pioneer Courthouse renovation. He highlighted the intricate process of excavating underneath the existing building and using temporary shoring to support the structure. The construction team then cut off the existing foundation, effectively placing the courthouse on stilts while they installed the new isolation system. This delicate operation required meticulous planning and execution to avoid any settlement cracks or damage to the historic fabric of the building. Another key element to success was maintaining the historic building core and courtrooms. Any movement of the building while the foundation was cut free could result in irreparable cracking of building finishes. By preplanning with engineers, we had minimal cracking and preserved the original finish.

The project was the first base isolation upgrade in Oregon, setting a precedent for future seismic retrofits in the region. Stegemoller noted that this method of earthquake preparedness is crucial for historic buildings in seismically active areas like Portland.

Beyond the technical achievements, the Pioneer Courthouse renovation was also a labor of love in terms of restoring its historical character. The interior of the courthouse was carefully refurbished to replicate its original features, preserving its architectural beauty while integrating modern safety measures. This balance of old and new exemplifies JE Dunn’s dedication to honoring the past while preparing for the future.

Stegemoller recounted a vivid story shared by Fred Shipman, a key figure in the project, about a particularly nerve-wracking moment. During the excavation, a worker operating a bobcat under the building brought the precarious nature of the work into sharp focus. The realization that one wrong move could bring down the entire structure underscored the high stakes and technical prowess required for such a project.

The Pioneer Courthouse now stands as a landmark of both historical significance and modern engineering excellence. Its successful renovation highlights JE Dunn’s ability to tackle the most challenging projects with innovation and a deep respect for heritage. The courthouse continues to serve the community, not only as a functional government building but also as a symbol of resilience and preservation. Through projects like this, JE Dunn demonstrates its commitment to enhancing the built environment while safeguarding the stories and structures of the past.

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