ABSTRACT
The purpose of this contribution is to conduct a survey of our current state of knowledge concerning various aspects of seismic phenomena significant for engineering applications, as improved in the light of recent destructive earthquakes worldwide. A first consideration is the characterization of sources and of propagation, more particularly in an intracontinental context. The modification of the incident bedrock motion by superficial layers is then addressed, including the definition of a “reference rock site” and the most recent attenuation relationships that have been elaborated. The Kobe earthquake of January 17, 1995, which yielded records from a vertical array, is used to analyze soil nonlinearity, the horizontal to vertical ratio, and its potential in microzoning.
