The p-Δ effect of structure will changed

because the near-fault earthquake ground motions has greater horizontal and vertical earthquake effect.First

the statistical analysis of the ratios of vertical-to-horizontal acceleration response spectrum and vertical-to-horizontal peak acceleration from 537 series of earthquake records will exhibit the characteristics of near-fault earthquake ground motions.Secondly

we conduct the elastic-plastic analyze of concrete structure with the p-Δeffect under near-fault ground motions with velocity impulse and near-fault ground motions and far-fault ground motions

analyse the influence of p-Δeffect.Finally

we consider horizontal and vertical ground motion at the same time

analyse the influence of p-Δeffect with vertical ground motion.Results indicate that near-fault earthquake ground motions have greater response spectrum value than usual

and it’s unsafe to take vertical ground motion as 65 percent of horizontal ground motion in near-fault regions.Structure has greater earthquake response under near-fault ground motions with velocity impulse in the case of same peak acceleration value.But it’s not obvious that structure response has p-Δeffect.Due to the randomness and complexity ofground motions

the inertial force caused by vertical ground motions can increase the response of structure and may also reduce the response of structure.