Analysis of Influence Factor of Earthquake Input Energy of Elastic SDOF Systems

420 earthquake wave records on 4 soil sites were classified into 12 groups according to classification method of ATC 3-06 seismic design code,and a great deal of elastic time history analyses of single degree of freedom(SDOF) systems were carried out.The influence parameters,including soil site,earthquake design group and damping ratio were emphatically investigated.At last,the related formulae between earthquake peak equivalent velocity and characteristic period were established by means of regression analysis considering the effects of different damping ratios.The results indicate that earthquake input energy decreases with damping ratio increasing.Soil site and earthquake design group have significantly effect on earthquake input energy.