Displacement Based Analysis of Rocking Structures

Abstract

The response of a rigid rocking block is traditionally described by its tilt angle. This is a correct description, but this paper suggests that describing rocking via displacements is more meaningful, because it uncovers that two geometrically similar blocks of different size will experience the same top displacement, provided that they do not overturn. Thus the displacement demand of a ground motion on a rocking block is only a function of its slenderness; not of its size. This allows for the construction of size independent rocking demand spectra.