LABORATORY MODELING OF ROCK FRAGMENTS’ DISPLACEMENTS DURING EARTHQUAKES

Abstract

Obtaining an accurate assessment of seismic hazard is complicated by the short time intervals for which seismic data are available, compared to the recurrence period of strong earthquakes. The problem can be solved by methods of paleoseismology. One of them, probably the most economical, is the method for estimating of peak ground velocities during strong paleo-earthquakes (PGVEM). The method is based on the interpretation of field observations of presumably seismogenic displacements of rock units. A series of laboratory modeling experiments were carried out to refine the error of the PGVEM method. For typical ground conditions the scatter of rock pieces displacements was examined, and the possibility of empirically observed cases of anomalously large displacements of rock blocks was indicated. Such cases can occur in the case of replacement of the sliding friction mode by displacement due to overturning of rock fragments. The conducted experiments allow us to propose a few recommendations to refine the application of the PGVEM method in field condition.