Quantitative Classification of Near-Fault Ground Motions Using Wavelet Analysis

Abstract A method is described for quantitatively identifying ground motions containing strong velocity pulses, such as those caused by near-fault directivity. The approach uses wavelet analysis to extract the largest velocity pulse from a given ground motion. The size of the extracted pulse relative to the original ground motion is used to develop a quantitative criterion for classifying a ground motion as “pulse-like. ” The criterion is calibrated by using a training data set of manually classified ground motions. To identify the subset of these pulselike records of greatest engi-neering interest, two additional criteria are applied: the pulse arrives early in the ground motion and the absolute amplitude of…