Reliability-based constant-damage ductility demand spectra of mid-rise RC building structures using modified equivalent linearization method.

In the displacement-based seismic design and evaluation, the equivalent linearization method is one of the approximation methods to estimate the maximum displacement response of a single-degree-of-freedom (SDOF) system. Based on the past research conducted by Okano & Miyamoto and the seismic design code in Taiwan, this work proposes modified equivalent linearization method (MELM) of a SDOF system for a mid-rise reinforced concrete (RC) building structure. By considering a modification factor suggested by the equivalent linear method proposed by Okano and Miyamoto and performing the nonlinear regression analysis, the accuracy of the proposed method can be improved. A total of 348 ground motions recorded on the various earthquakes are used to calculate error statistics of MELM. Additionally, a closed-form formula for the constant-damage ductility demand spectrum (CDDDS) that corresponds to a specified reliability is suggested in this work. [ABSTRACT FROM AUTHOR]