Effect of pulse characteristics of near-fault ground motions on the response of equipment-structure coupled isolation system

Based on the model of equipment-structure coupled isolation system, 50 near-fault pulse-like seismic waves were selected and the effect of period ratio T_P/T （the ratio of the pulse period to the basic period of the structure） and pulse energy on the structural response was analyzed using T_P/T＝1 as the dividing line; and the relationships between the displacement ratio of isolation layer and the period ratio and pulse energy were fitted while the zero-crossing times is not less than 5. The analyses show that the influence of pulse characteristics on the structure is mainly related to the period ratio T_P/T and the pulse energy, while the influence of the zero-crossing times of the acceleration curve corresponding to the velocity pulse needs to be considered. Furthermore, the equipment response is directly related to the top floor acceleration, but there is no significant direct correlation with the pulse characteristics of near-fault ground motions.