Seismic assessment of unreinforced masonry buildings in Boston's Back Bay neighborhood

Abstract

This thesis presents a seismic evaluation of the unreinforced masonry buildings in Boston Massachusetts's historical Back Bay neighborhood. This Boston district, famous for its rows of Victorian brownstone residences is considered to be one of the best preserved examples of 19 'h century urban design. There are a few specific reasons to speculate at the vulnerability of this neighborhood to seismic events. First, in 1755, one hundred years before the Back Bay started to be built, the most massive earthquake of New England's history occurred, damaging unreinforced masonry structures in Boston. Approximately eighty percent of the Back Bay neighborhood is now made up of unreinforced masonry structures. Second, seismic design was not required in Boston until 1975, which means a staggering majority of the buildings in the Back Bay were constructed without any kind of anti-seismic lateral system. The aim of this thesis is to assess the structural response of the unreinforced masonry homes of the Back Bay to seismic activity due to these issues. A case study of an unreinforced masonry building in the neighborhood is assessed through structural analysis of its facade and party walls. The performance of this building is extrapolated to represent the state of the unreinforced masonry buildings of the Back Bay.