Modified Damage Assessment Method for Reinforced Concrete Buildings

A damage index study is necessary for evaluating the post-earthquake health of structures, and it is also required in performance based seismic design (PBSD), where engineers can design a structure for desired predefined target performance objectives. The existing damage assessment methods give different magnitudes of story damage index (SDI) or global damage index (GDI) for a given building under the same hazard level. These existing methods also give different SDI patterns. Therefore, it is difficult to identify the appropriate method to estimate the damage index (DI) for a structure. In this paper, 14 different existing damage assessment methods were studied to investigate their characteristics and reliability. The aim of this study is to determine appropriate and reliable damage assessment methods amongst the available existing methods, and to propose a new multivariate damage assessment model combining those reliable damage assessment methods. Based on the statistical hypothesis T-test conducted for 14 existing model equations, three methods are found to be most reliable and effective to assess the DI of buildings, meeting a 95% confidence level. Combining these three models, a new multivariate damage assessment model is proposed that shows a good agreement with those models, having ${\mathrm{R}}^2=0.91$. This study resolves the ambiguity in selection of the most reliable methods among the existing models.