Seismic Retrofit of a Machine Shop at the Puget Sound Naval Shipyard

Building 431 at the Puget Sound Naval Shipyard & Intermediate Maintenance Facility in Bremerton, Washington houses the primary machine shop used to maintain the Navy ships and submarines on the West Coast. The historic 640,000 square foot steel, concrete, wood, and masonry building was constructed in 1935, underwent significant additions during World War II, and has been continually modified since that time. KPFF was the structural engineer on the design team tasked by the Navy to design seismic strengthening for the building that would satisfy the enhanced performance objectives required for this mission-critical structure. The design for the seismic retrofit of the structure began in 2013 using the ASCE/SEI 41-13 Standard (ASCE-41). KPFF employed several interacting design methods to achieve the required performance goals, including nonlinear response history analysis (NLRHA), selective weakening of existing perimeter walls, and 71-foot-long buckling restrained braced frames (BRBFs) added to the building’s exterior.