Dynamic Eccentricities in Pushover Analysis of Asymmetric Single-Storey Buildings

Abstract

Α new version about a method of documented application of pushover analysis on reinforced concrete, asymmetric single-storey buildings has recently been presented. To rationally consider the coupling between torsional (about vertical axis) and translational vibrations, the equivalent lateral static floor force of the proposed pushover method is applied using suitable dynamic eccentricities which are added with the accidental ones in such a way that the final design eccentricities move the application point of the external, lateral, static, floor force away from the diaphragm Mass Centre. The appropriate dynamic eccentricities for the stiff and the flexible side of the floor plan are related to the so-called “Capable Near Collapse Principal Axes”, reference to the Near Collapse limit state, derive from extensive parametric analysis, and are calculated by graphs and suitable equations. In the present work, a numerical example of a (double) asymmetric single-storey building is presented to clarify the step by step application of the proposed pushover analysis method. It is a torsional sensitive r/c building, designed in accordance with Eurocodes EN 1992-1 and 1998-1 for ductility class high (DCH). The proposed method is evaluated relative to the results of non-linear response history analysis (RHA). The final results show that the proposed method of pushover analysis predicts with safety the displacement of the stiff side of the building as well as that of the flexible side.