Evaluation of two approaches to simulate spatially variable ground motions

Spatial variability of ground motions has significant influence on dynamic response of extended structures such as bridges and tunnels. This study systematically evaluates two commonly used procedures for developing spatially variable ground motion time series considering incoherency effect, wave passage effect, and effect of intermediate stations. The evaluation included the methods' ability to: handle general forms of incoherency function, correctly account for wave passage, conserve energy, and be minimally influenced by the presence of intermediate stations. The method that can mostly satisfy these requirements is identified in this article.