Seismic retrofitting of unreinforced masonry buildings

Abstract

Masonry is one of the oldest building materials to exist. It is seen throughout history in many well-known and historical structures all around the world. Masonry is strong in compression but weak in tension. With it being such a prominent and old material, there are many existing structures that lack proper reinforcement. Because of this reason, many of these buildings are at risk of failure under earthquakes, which can cause serious structural damage, injury, and even fatalities. The failure of these structures can be prevented by newly developed technologies. There are many retrofitting techniques that can be used for unreinforced masonry. This report covers just a few of the methods that are available today, including grout and epoxy injections, carbon fiber reinforced polymers (CFRP), parapet bracing, out-of-plane wall bracing, shotcrete, and diaphragm ties. These methods have been proven to improve the stability and strength of unreinforced masonry buildings during a seismic event. This report seeks to summarize these methods and to discuss some technical details on how to use them to retrofit existing unreinforced masonry structures.