  This paper aims at the analysis of seismic wave amplification in a deep
alluvial basin in the city of Tunis in Tunisia. This sedimentary basin is 3000m
wide and 350m deep. Since the seismic hazard is significant in this area, the
depth of the basin and the strong impedance ratio raise the need for an
accurate estimation of seismic motion amplification. Various experimental
investigations were performed in previous studies to characterize site effects.
The Boundary Element Method is considered herein to assess the parameter
sensitivity of the amplification process and analyse the prevailing phenomena.
The various frequencies of maximum amplification are correctly estimated by the
BEM simulations. The maximum amplification level observed in the field is also
well retrieved by the numerical simulations but, due to the sensitivity of the
location of maximum amplification in space, the overall maximum amplification
has to be considered. The influence of the wave-field incidence and material
damping is also discussed.
