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 are not close to overturn. The
above is illustrated for both analytical pulse excitations and for recorded ground motions.
Thus, the displacement demand of a ground motion on a rocking block is only a function of …

Rocking can be used as a seismic isolation strategy for bridges and buildings. Letting a
structure uplift works as a mechanical fuse and limits the design forces of both the
foundation and the superstructure. Interestingly, there is no correlation between the rocking
oscillator and the elastic one. Therefore, there is not any “equivalent linear system” and the
elastic spectra are useless when it comes to rocking. Thus, there is no simplified design
procedure that a practicing engineer could use. In order to create design rocking spectra, the …