Combination model for conventional pushover analysis considering higher mode vibration effects.

Summary: This paper aims to propose a combination model for conventional pushover analysis with invariant lateral load patterns to consider the effects of higher mode vibrations on the seismic responses of high‐rise buildings. Rectangular concrete‐filled steel tubular (RCFT) structures having two types of deformation, namely, shear type RCFT frame structures and shear‐flexural type RCFT frame‐shear wall structures, are selected and investigated. Finite element models are created using Perform‐3D. Both pushover analysis with three conventional lateral loading patterns, namely, uniformly distributed loading, first‐mode vibration loading, and concentrated loading at the vertex, and time‐history analysis with 15–21 earthquake records chosen for each RCFT structure are performed. Regression analysis is used to fit the interstory drift ratios obtained by the pushover analysis with those from the time‐history analysis. Further, the relations between the partial regression coefficients and the structural fundamental periods under certain lateral loading patterns are analyzed. On this basis, using these conventional lateral loading patterns, combination models for high‐rise buildings with two types of deformation are proposed and verified. The results demonstrate that the proposed method can estimate the seismic responses of high‐rise buildings with a high accuracy and has the advantages of ease of implementation and operation. [ABSTRACT FROM AUTHOR]