To further elucidate the vertical and horizontal component characteristics of near-fault ground motion,1202 sets of ground motion in the PEER database were counted to statistically analyze strong near-fault ground mo-tion in this study.The characteristics of the vertical-to-horizontal peak acceleration ratio(PGAv/PGAh),vertical-to-horizontal response spectrum ratio(Sav(T)/Sah(T)),and arrival time interval between horizontal and vertical acceleration peaks were studied.Furthermore,the relationships between PGAv/PGAh and fault distance,site con-ditions,and focal mechanism were discussed.The lognormal distribution was applied to fit the distribution of PGAv/PGAh under different site conditions and focal mechanisms.Moreover,the change laws of different fault dis-tances and site conditions on Sav(T)/Sah(T)were compared.The correlation between the amplitude of peak accel-eration and the arrival time of vertical and horizontal near-fault ground motion was studied,providing advice on the selection of vertical ground motion in structural analysis.The results reveal that fault distance,site conditions,and focal mechanism influence the vertical component.Vertical ground motion with strong high-frequency content tends to be observed in stations with a smaller fault distance,slower shear wave velocity,and bad site conditions,where-as vertical ground motion with strong low-frequency content tends to be observed in stations with a larger fault dis-tance and good site conditions.An obvious linear relationship exists between the vertical component and the geo-metric mean of two orthogonal horizontal components of ground motion in the amplitude of peak acceleration and the arrival time.
关键词
近断层/竖向水平加速度峰值比/加速度峰值比/反应谱比/加速度峰值到达时间/断层距/场地/震源机制
Key words
near fault/vertical ground motion/peak acceleration ratio/response spectrum ratio/arrival time of ac-celeration peak/fault distance/site/focal mechanism
维普
万方数据