On Conditional Simulation of Spatially Varying Rotational Ground Motion

Authors elsewhere reported two frameworks for conditional simulation of spatially varying translational ground motion, namely, (i) cross-spectral density (CSD) based framework and (ii) auto-spectral density (ASD) based framework. This paper investigates the applicability of both the frameworks for rotational components. Rotational components are extracted here using one of the Single Station Procedures reported in the literature. Spatially varying rotational ground motion for a future event is explored using a coherency model calibrated against a past event and an estimate of ASD of the seed (rotational) ground motion. Choice of representation of ASD is also investigated.