The contribution of cord rotations to structural response in the near-field

Abstract The response of structures with large plan dimensions depends on the wave motion beneath their extended or multiple foundations. In addition to translational components of motion, which are different at the base of each column, or at different points of large foundations, point rotations at the base of individual foundations—as well as cord rotations between adjacent column foundations—all contribute to the overall response. The response contribution from all these components of motion becomes particularly significant in the vicinity of moving faults, in which near-field terms in the wave motion contribute large pulses and large permanent ground displacements. In this work, we examine the relative significance of point and cord rotations in an idealized representation of a structure excited by fault normal pulse d F ( t ) and fault parallel displacement d N ( t ) .