Design method for slender columns subjected to biaxial bending based on second-order eccentricity

Abstract

The present paper proposes a simplified method to design slender rectangular reinforced concrete columns with doubly symmetric reinforcement. The proposal is based on the computation of the second-order eccentricity method from the Eurocode 2 (December 2004). It is valid for columns subjected to combined axial loads and either uniaxial or biaxial bending, short-time and sustained loads, and also for normal- and high-strength concretes. It is only suitable for columns with equal effective buckling lengths in the two principal bending planes. It is an extension for biaxial bending of the column-model method. The current paper is the second part of a research study conducted by the current authors. The method was compared with 371 experimental tests from the literature and a high degree of accuracy was obtained. Precision for sustained loads and biaxial bending was improved in comparison with the method proposed by Eurocode 2 (December 2004). The method allows slender reinforced concrete columns to be both checked and designed with sufficient accuracy for engineering practice.