Financial and Environmental Payback Periods of Seismic Retrofit Investments for Reinforced Concrete Buildings Estimated Using a Novel Method

Abstract

Generally, in seismic retrofit design, seismic performance of a RC building can be upgraded to meet or exceed code requirements by upgrading the structural strength, ductility, or a combination of both. Except for safety, financial and environmental benefits of seismic retrofit investments are not considered in seismic retrofit design. However, financial and environmental benefits are very important information for decision making in seismic retrofit investments. In this work, a novel method for estimating seismic damage to an RC building is constructed based of the hazard curve of response spectral acceleration. Additionally, earthquakes are assumed to follow a Poisson process when analyzing the probability of a specified damage state within a specified service period and modeling expected costs caused by seismic damage. In addition to costs, CO2 emissions caused by seismic retrofit and repairs are considered the environmental impact when assessing payback periods of seismic retrofit investments based on the economic and environmental aspects of low-rise RC buildings. In a case study, 16 practical seismic retrofit projects for RC school buildings in Taipei, Taiwan, were analyzed to determine their financial and environmental payback periods. This paper shows that return on the seismic retrofit investments was both environmentally and economically positive.