Post-earthquake preliminary seismic assessment method for low-rise RC buildings in Taiwan

Abstract

After the 1999 Chi-Chi Earthquake in Taiwan, to improve the safety of a huge number of low-rise reinforced concrete (RC) buildings, including typical RC school buildings and street houses, preliminary seismic assessments were conducted to pre-screen for seismic capacity. The main purpose of this work is to modify the existing preliminary seismic assessment method to make it applicable to earthquake-damaged low-rise RC building structures. In this work, reduction factors of strength, stiffness and energy dissipation, which are based on experimental data in past research, are used to modify the nonlinear plastic hinges of damaged RC column members with various damage levels. Additionally, the behavior of modified nonlinear plastic hinges is verified using experimental data. To develop a method of preliminary seismic assessment for a damaged low-rise RC building structure, the reduction factors of shear strength per unit area are suggested using the modified nonlinear plastic hinges of the damaged RC column members. Furthermore, the effect of the stiffness reduction on the development curve of strength of an RC column member is also considered in determining the reduction factors of shear strength per unit area for the preliminary seismic assessment. Finally, in a case study of ten real damaged low-rise RC building structures, in addition to the strength reduction factors, a post-earthquake preliminary seismic assessment method is thus proposed and verified using the detailed seismic assessment method.