Considering ground motion to establish equivalent single degree of freedom systems for modal pushover analysis procedure

Abstract:

This paper presented a newly-developed analysis procedure for establishing equivalent single degree of freedom systems (ESDOF),based on the modal pushover analysis procedure with higher precision.The modal pushover analysis procedure was limited in terms of its inability to account for ground motion when establishing ESDOF.The suggested method overcomes the shortcoming.This method is characterized by its high efficiency of calculation and clear physical meaning,which eliminates the need to calculate modal combination step by step.And it was validated by calculating a shaking table test of a 12-storey reinforced concrete frame model.The structure model was calculated separately using nonlinear time history method,the method introduced herein and conventional modal pushover analysis procedure.Through the comparison of the calculation results,it was found that the higher-mode relative excited magnitude by ground motion is the main reason for modal coupling.And the suggested method yields higher precision than conventional modal pushover analysis procedure,especially for high frequency ground motion.So it has good adaptability.