On the recovery of peak ground velocity and peak ground displacement from strong-motion records

Peak ground velocity (PGV) and peak ground displacement (PGD) are important strong ground motion parameters for correlating with damage caused by an earthquake, for analysis of existing structures and for the design of new structures. Unlike peak ground acceleration, PGV and PGD are greatly affected by the accelerogram processing technique used. PGD is composed of two parts: the transient displacement which should equal zero at the end of the record and the displacement due to a permanent movement of the recording station, caused by fault slip or foundation failure for example. In the near field of large earthquakes permanent displacements can be much larger than transient displacements; however they are not recovered by standard processing methods based on filtering. Filtering of strong-motion records leads to underestimating PGV and PGD for large earthquakes which can have an important effect on work that employs these parameters.