Inelastic Response of Reinforced Concrete Columns Subjected to Two-Dimensional Earthquake Motions

This study was undertaken to determine the effects of two-dimensional earthquake motion on reinforced concrete (R/C) columns. An analytical model to represent the shear-deflection-axial load relationship of RIC columns is developed from stress-strain relations of steel and concrete. Improved hysteresis model for steel included the Bauschinger effect and the model for concrete included the deterioration of strength and stiffness under cyclic loading. The lumping of concrete at the end sections for calculating moment-curvature relationships in conjunction with an assumed curvature distribution along the column leads to an efficient procedure for the calculation of the shear-deflection-axial load relationship for RIC columns. The analytical model compares favorably with experimental results for both uniaxial and biaxial loading conditions. The analytical model predicts significant.changes in the strength, energy absorption capacity and accumulated damage responses of the column under biaxial deformations as compared to the corresponding responses under uniaxial deformations.National Science Foundation Grant ENV 75-08456National Science Foundation Grant ENV 77-0719