Overturning of rigid blocks for earthquake excitation

Overturning of rigid blocks on rigid foundations subjected to earthquakes in principle can be analyzed by simple replacement signals. The effect of a signal is generally characterized by its overturning curve. In this paper a new approach is presented, which is based on the overturning acceleration spectra (OAS). It is shown that an earthquake can be reasonably well represented for overturning by two parameters: the peak ground acceleration and the replacement impulse duration. In the paper the OAS of rigid blocks is presented for 100 different earthquake records. Based on the replacement impulse duration a simple design method is presented to predict the safety of rocking blocks.