Seismic Retrofit and Historic Preservation of a San Francisco Banking Temple

Abstract

Constructed in 1892 with a seamless addition completed in 1904, the Hibernia Bank Building is an unreinforced brick and granite masonry San Francisco banking temple. After being abandoned for over a decade, in 2010 a new owner sought to renovate the building to once again allow occupancy, but this time for assembly use. Seismic improvements supplemented the inherent strengths of the historic masonry, especially the structural mechanism of rocking that allowed the unreinforced masonry building to survive the 1906 earthquake relatively unscathed. Limited concrete shear walls were added as part of the retrofit, but placed discretely and surgically in the structure, located away from historic finishes which have survived remarkably intact despite decades of neglect. This paper will discuss the three-dimensional computer model that was used to validate the seismic retrofit scheme, including the use of nonlinear rocking piers, as well as the design of the concrete diaphragm strengthening using externally bonded and near-surface mounted Fiber Reinforced Polymers (FRPs).