Congregation Sherith Israel, one of San Francisco’s lesser known gems, is an
historic unreinforced masonry building with a naturally lighted dome that rises over 100 feet
above its centerpiece --- an ornate mural painted vaulted sanctuary that occupies nearly 90
percent of the plan area of the building. Though damaged only modestly by the 1906
earthquake that destroyed many of its unreinforced masonry neighbors, it was subject to a
local seismic upgrade ordinance. Various innovative strengthening techniques --- including
the first known use in North America of super-elastic nitinol for seismic resistance ---
were implemented to supplement the structure’s inherent strengths. The design was
developed to permit historically significant features to remain virtually undisturbed;
construction was completed in 2017.
The building was required by the municipality to be strengthened to meet seismic
safety standards for assembly occupancy. Following years of study, a strengthening plan
that was feasible and cost-effective, yet would not harm the historic interiors and exterior, was
developed and installed. Construction involved an initial phase of more traditional
strengthening in 2010 to maintain occupancy on an interim basis, followed by a second
phase of innovative technologies to achieve full compliance.
The strengthening philosophy relied heavily on supplementing, rather than supplanting
the existing building’s strengths and leveraging its natural dynamic characteristics. The nitinol
was designed to provide cost-effective easy-to-install structural “fuses” within an
octagonally-configured tension tie system to promote re-centering and control out-of-phase,
out-of-plane behavior of the vulnerable gable end walls, parapet and arches that define the
main facades. Though the nitinol interconnects all four gable end walls, the octagonal
configuration of the system causes no disruption to the domed sanctuary by circumventing
the interior dome, and the sanctuary today is in the same condition as before the project.
The supplemental seismic work included a fiber reinforced polymer catenary and rocking
compression-only pilasters to control displacements without incrementing the demand on its
floor-to-wall ties.
Abstract
Congregation Sherith Israel, one of San Francisco’s lesser known gems, is an
historic unreinforced masonry building with a naturally lighted dome that rises over 100 feet
above its centerpiece --- an ornate mural painted vaulted sanctuary that occupies nearly [...]