Lateral-Load Behavior Prediction and Pushover Analysis of Reinforced Concrete Columns Including Shear Effects

摘要

A model for predicting the lateral load-deformation response of reinforced concrete (RC) columns subjected to combined bending and shear loads is proposed based on existing analytical models and experimental data from 38 column tests. In this model, the flexural and slip deformations of RC columns are predicted by available models, and the shear deformations are evaluated by the proposed formulas obtained from experimental data analysis and parametric study. The expressions for unloading and reloading stiffnesses, corresponding to different displacements of RC columns, are developed by analyzing the relation between unloading stiffness, reloading stiffness and initial lateral stiffness of columns, respectively, and the expression for calculating equivalent damping ratio according to hysteresis loop area is also provided. Moreover, a single-degree of freedom (SDOF) system is analyzed to illustrate the applications of the proposed model for developing the corresponding capacity curve and demand curve in pushover analysis. Finally, a parametric study is conducted to assess the effect of primary parameters on the seismic performance of columns, such as shear-span ratio, axial load ratio, longitudinal reinforcement ratio and stirrup ratio.