Seismic capacity evaluation and risk estimation of existing low-rise reinforced concrete buildings in Korea

Abstract

The main purpose of this study is to propose a method for evaluating the seismic capacity of existing low-rise reinforced concrete buildings in Korea by reviewing the applicability of the Japanese Standard. Based on the seismic capacity of Korean buildings evaluated by this standard, we modified the basic structural index, which is calculated in terms of the ultimate horizontal strength and ductility. We compared our experiment results to the values calculated using the strength equations for columns and walls from the Japanese Standard. The flexural strength equations could be applied without modification, while the shear strength equations required modification. We evaluated these modified strength equations and proposed unit average shear stresses of columns and walls based on statistical data relating to the structural characteristics of Korean buildings. The values of the ductility indices, which are primarily calculated based on the shear-to-flexural capacity ratio, of Korean buildings with hoop spacing wider than 300 mm, as computed by the proposed method, were more reasonable than those calculated by the Japanese Standard. We used a probabilistic approach to estimate the structural damage ratios of Korean buildings due to 0.1 g, 0.15 g and 0.2 g earthquakes as 7 %, 27 % and 55 % respectively. We believe that the proposed method provides a useful strategy for identifying Korean buildings that are vulnerable to seismic activity, and recommend urgent earthquake preparedness measures. © 2019 by Korea Concrete Institute.