Probabilistic impedance of foundation: Impact of the seismic design on uncertain soils

R. Cottereau (1) , Didier Clouteau (1) , Christian Soize (2)

1 MSSMat - Laboratoire de mécanique des sols, structures et matériaux
2 MSME - Laboratoire de Modélisation et Simulation Multi Echelle

In the linear seismic design of buildings, the (deterministic) substructure method is a customary and efficient approach. However, the existence of spatial variability in the parameters of the mechanical model of the soil, as well as parametric errors, calls for the use of probabilistic approaches in order to provide a reliable design of the structure. The construction of probabilistic models of the soil impedance matrix provides a natural path to such approaches within the context of the substructure method. Two main techniques are described in this paper: a parametric one, typically using the stochastic finite element method, and a nonparametric one, which was introduced more recently. The latter is explored more specifically, and the possibilities it offers in terms of seismic design are presented. In particular, it is shown that it allows for the estimation of quantiles of the quantities of interest, rather than confidence intervals, which lead to highly conservative design.

Mots clés: uncertainty quantification; soil impedance matrix; probabilistic design; lumped-parameter model; substructuring method; stochastic finite element method; nonparametric probabilistic method; random matrix; model uncertainties; modeling errors; random medium; soil-structure interaction

Domaines: Mécanique des solides [physics.class-ph]; Probabilités [math.PR]; Statistiques [math.ST]

R. Cottereau, Didier Clouteau, Christian Soize. Probabilistic impedance of foundation: Impact of the seismic design on uncertain soils. Earthquake Engineering and Structural Dynamics, 2008, 37 (6), pp.899-918. ⟨10.1002/eqe.794⟩. ⟨hal-00685116⟩