A multi-scale seismic response of two-dimensional sedimentary valleys due to the combined effects of topography and geology.

Behrouz Gatmiri (1, 2) , Solenn Le Pense (3) , Pooneh Maghoul (4)

1 ANDRA - Agence Nationale pour la Gestion des Déchets Radioactifs
2 Departement of Civil Engineering
3 cermes - Géotechnique
4 navier umr 8205 - Laboratoire Navier

It is well known that the response of a site to seismic excitation depends on the local topographical and geological conditions. The current building codes already take into account unidimensional site effects but ignore complex site effects due to two-dimensional irregular configurations. The aim of this work is to contribute to the establishment of a simple predictive method to estimate site effects. The horizontal ground movements at the surface of sedimentary valleys subjected to SV waves with vertical incidence are calculated by using the HYBRID program, combining finite elements in the near field and boundary elements in the far field (FEM/BEM). A parametric study is conducted to examine the combined effects of topography and geology on the amplification of the response spectrum at various points across the valley. The influence of different parameters is considered, such as filling ratios (from empty to full valleys), impedance contrasts between bedrock and sediments, and dimensions.

Mots clés: Seismic site effect; Seismic amplification; Building codes; Seismic response spectrum; Hybrid numerical method; Sedimentary valley; 2D configurations

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Behrouz Gatmiri, Solenn Le Pense, Pooneh Maghoul. A multi-scale seismic response of two-dimensional sedimentary valleys due to the combined effects of topography and geology.. Journal of Multiscale Modeling, 2011, 3 (3), pp.133-149. ⟨10.1142/S1756973711000455⟩. ⟨hal-00667869⟩