Civil Engineering Association

THE EFFECTIVENESS OF SEISMIC BUILDING CODE PROVISIONS ON REDUCING THE COLLAPSE RISK OF REINFORCED CONCRETE MOMENT FRAME BUILDINGS

This paper examines the effectiveness of building code provisions in mitigating seismic collapse risk by quantifying the collapse risk of four reinforced concrete framestructures. First, an existing and a
new reinforced concrete moment frame building, designed for seismic conditions in coastal California, are compared to illustrate improvements in building code provisions over time, asmeasured in terms of reduction in collapse risk. This comparison is based on four-story reinforced concrete moment frame structures designed to be representative of a) pre-1970 non-ductile reinforced concrete construction and b) modern, ductile reinforced concrete construction. A second group of four-story reinforced moment frame structures is also considered, including modern code-conforming a) special, b) intermediate, and c) ordinary moment frames. These structures are designed for three different sites and the strength and detailing requirements are consistent with what is permitted for each site’s seismic hazard. From analysis of these structures, the uniformity of safety provided by seismic building code provisions across regions of varying seismicity is evaluated.