Near-Field Earthquake Directivity Effects: Application to Seismic Evaluation of Bridges

Directivity is observed in the near-field regime, where there are a few strong-motion records. Depending on the pulse period of directivity, pulse-like ground motion caused by directivity can cause severe damage to structures. Earthquake simulations are used to simulate time histories on racetracks where the rupture distance of receivers remains constant regardless of the location of the earthquake hypocenter. Choosing a vertical strike-slip fault, a bilateral, a unilateral and a couple of intermediate levels scenarios are simulated on multiple tracks. The ground motion is synthesized to understand the response of structures ranging from single degree of freedom approximations to bridge models.