钢筋溷凝土柱初始刚度_Initial_Stiffness_of_Reinforced_Concrete_Columns.pdf

Initial Stiffness of Reinforced Concrete Columns with Moderate Aspect Ratios Cao Thanh Ngoc Tran1 and Bing Li2,* 1Department of Civil Engineering, International University, Vietnam National University, Ho Chi Minh City, Vietnam 2School of Civil and Environment Engineering, Nanyang Technological University, Singapore 639798 (Received: 1 December 2010; Received revised form: 17 May 2011; Accepted: 4 June 2011) Abstract: The estimation of the initial stiffness of columns subjected to seismic loadings has long been a matter of considerable uncertainty. This paper reports a study that is devoted to addressing this uncertainty by developing a rational method to determine the initial stiffness of RC columns when subjected to seismic loads. A comprehensive parametric study based on a proposed method is initially carried out to investigate the influences of several critical parameters. A simple equation is then proposed to estimate the initial stiffness of RC columns. The applicability and accuracy of the proposed method and equation are then verified with the experimental data obtained from literature studies. Key words: reinforced concrete, column initial stiffness, stiffness ratio. 1. INTRODUCTION method was carried out to investigate the influences of In recent years, earthquake design philosophy has shifted several critical parameters. A simp