Development of displacement profiles for direct displacement based seismic design of regular reinforced concrete frame structures

Abstract

The structural displacement profile is vital for determining the equivalent single degree-of-freedom system parameters and the distribution of design lateral forces in the Direct Displacement-based Design (DDBD). In this paper, adaptive pushover analyses are conducted for 66 RC frame structures with various configurations and design parameters to calculate the lateral displacement, and the changing law of plastic hinge distribution and deformation mechanism of RC frame structures is investigated. Based on the analysis results, a refined displacement profile expression is proposed where the effect of elastic first order mode, maximum interstory drift, column-to-beam strength ratio, height-width ratio and the drift at first plastic hinge formation are involved. Its accuracy and reliability are validated by compared with the results of nonlinear time history analyses. Finally, an example is provided to illustrate the application of the proposed displacement profile expression in design considering multiple performance objectives.