The microzonation of Fabriano – Deterministic computation of the reference ground motion in Fabriano (Marche, Italy)

 

The reference ground motion due to an earthquake in Fabriano (Marche, Italy) is estimated with a deterministic approach. The scenario earthquake – the April 24, 1741, M= 6.2 “Fabrianese" event – simulates the maximum expected event close to the town. The ground motion is computed by the “wavenumber integration method", a 3-D method which solves the full equation of seismic wave propagation through a layered medium.

 

The reference ground motion due to an earthquake in Fabriano (Marche, Italy) is estimated with a deterministic approach. The scenario earthquake – the April 24, 1741, M= 6.2 “Fabrianese" event – simulates the maximum expected event close to the town. The ground motion is computed by the “wavenumber integration method", a 3-D method which solves the full equation of seismic wave propagation through a layered medium.

In the first part of this study, the effect due to changes of the epicentral distance and hypocentral depth is evaluated.

In this case, the earthquake is represented by a point source. In the second part, an extended source is simulated. The ground motion is computed at different epicentral distances, though at the same source-receiver azimuth.

The main results of this study consist of a data set of seismograms, peak values of the ground motion, and Fourier and response spectra. It is shown that the ground motion depends strongly on both the source parameterisation (depth and focal mechanism) and the source-receiver geometry (distance and azimuth). For instance, a deeper source has the effect of moving the zone of peak ground motion far from the epicentral area. On the contrary, the ground response is only weakly sensitive to moderate variations of the crustal model. Response spectra are consistent with those computed independently by a different approach, such as those estimated from empirical attenuation laws and probabilistic methods. Finally, simulations predict no relevant effect of the rupture directivity on the ground response in Fabriano. This fact follows probably from the particular position of the town with respect to the fault plane, i.e., sideways to the fault on the hanging wall.


  The refe …


AUTORI: Priolo E.
RIG ANNO:2000 NUMERO:2
Numero di pagine: 59


Allegato: https://associazionegeotecnica.it/wp-content/uploads/2010/03/RIG_2001_2_59.pdf
Allegato:
Articolo completo: https://associazionegeotecnica.it/wp-content/uploads/2010/03/RIG_2001_2_59.pdf