Influence of Epicenter Distance on Vertical Earthquake Ground Motion Duration

The influence of epicenter distance on vertical earthquake ground motion duration was discussed based on American strong ground motion records.It is notable for the influence of epicenter distance on earthquake ground motion duration through analysis.In the study,regularity is different on various magnitudes.As a whole,the greater the epicenter distance is,the longer the duration is.The influence of magnitude on duration is considerable,so it may not be neglected.