Characterizing the Rotational Components of Earthquake Ground Motion.

摘要

Rotational components of ground motion, torsion about the vertical axis and rocking about orthogonal horizontal axes are not routinely considered in seismic design because such components have not been recorded and their effects on the response of structures are unknown. Rotation recordings are unavailable because instruments are by-and-large unavailable. Thus, the characterization of rotational components of ground motion is a focus of the report. Two categories of procedures are derived to extract rotational components of ground motion from recorded translational data: Single Station Procedure (SSP) and Multiple Station Procedures (NSP). Single station procedures employ translational acceleration time series recorded in an array of closely spaced but spatially distributed accelerographs.