U.S. General Services Administration
JE Dunn Construction
Constructed between 1869 and 1875 Pioneer Courthouse is the oldest standing federal courthouse west of the Mississippi and the second oldest federal facility on the West Coast. In 1994, KPFF evaluated the condition of the building, recommending seismic upgrade options to preserve this National Historic Landmark building.
In 2001 KPFF subsequently led the design of seismic strengthening and site improvements to preserve the three-story, 57,000 SF masonry and stone structure. A base isolation system was selected over conventional reinforcement techniques to reduce the amount of structural bracing and leave the historic architectural finishes intact. This required excavating beneath the entire structure and constructing a new pile supported foundation with 75 isolators that decoupled the building’s movement from that of the ground. A friction pendulum system (FPS) was used, and paired with a limited number of supplemental concrete shear walls, strengthening of wood floor diaphragms with additional anchorage to masonry walls, continuous ties, and additional tension chords and collector elements, completed the upgrade.
KPFF provided surveying and civil engineering services for the site improvements. This involved a new storm drainage system, domestic and fire protection water lines, and natural gas lines. A new driveway for a below-grade parking structure, new concrete walkways, and repair to damaged areas of the perimeter seat wall completed the renovation.