Vector-valued Probabilistic Seismic Demand Assessment of Structures under Two-Component Ground Motions

Document Type : Structural Earthquake Engineering


1 Islamic Azad University, Tehran, Iran



The present paper is an attempt to quantify probabilistic seismic demand of three-dimensional structures under two-component (vector-valued) ground motions, focusing on the collapse region of nonlinear response. While utilizing results of de-aggregated vector-valued probabilistic seismic hazard analysis (V-PSHA) as the seismic demand input, the assessment procedure is essentially based on results of nonlinear incremental dynamic analysis (IDA) of the three-dimensional (3D) model of the structure. Response of the structure is formulated based on the SRSS combination of the structure maximum inter-story drifts in plan orthogonal directions assuming log-normal distribution of the demands. The efficiency of the proposed procedure is demonstrated via a detailed step-by-step example with different period of vibrations and structural properties in orthogonal directions, which proves the adequacy of the method for practical vector-valued probabilistic seismic evaluation of regular and irregular structures.