Target acceleration in multimodal pushover method for R/C frames

Abstract

The procedure of searching the target ground acceleration as a measure of the lowest seismic resistance is presented in the paper. This objective is achieved by the multimodal pushover analysis based on the envelope principle. The pushover method founded on the linear combination of modes (L), and on mode combinations as a square root of the sum of the squares (SRSS), is presented. Examples of 5-storey and 9-storey R/C frames point to a highly significant influence of higher modes. The failure ground acceleration in multimodal pushover analysis is significantly lower, and even several times lower, compared to the single mode acceleration.