Interaction site-ville: Approches expérimentales et numériques

At the scale of a city, surface structures such as buildings can modify the "free field" seismic motion and act like secondary seismic sources. A number of observations have been conducted on actual datasets; these have demonstrated that such an effect may indeed be significant. The direct consequence of this "site-city interaction" is the contamination of seismic motion in an urban setting by a secondary wave field. Both centrifugal and numerical modeling efforts tend to confirm that this phenomenon is not incidental. More specifically, results indicate that between two buildings located close to one another, interactions occur that modify not only the soil movement but also the response of structures subjected to the movement. At the scale of a city, this phenomenon will become even more pronounced whenever strong coupling exists between the soil response and the response of the urban environment.