Effet des proprietes stochastiques de sol sur la reponse des fondations filantes reposant sur des sols non-homogenes

Abstract EN

The objective of this work is to study the effect of spatial variability of the soil properties on the rigid strip foundation resting on inhomogeneous soils re- sponse using probabilistic method of indirect simula- tion field random non-Gaussian for simulation of soil properties.

Soil properties of interest are shear mod- ulus, damping ratio, Poisson ratio and density, mod- eled as spatially random fields.

The shear modulus is assumed to be lognormal distributed, this choice is motivated by the fact that this soil property is positive parameter, and lognormal distribution enables ana- lyzing its large variability.

Because damping ratio, density and soil Poisson ratio are bounded in practice between two extreme values, their random fields are obtained from the Beta distribution, where the Beta field is determined, by performing a mapping tech- nique on the lognormal probability distribution func- tion diagram.

In this frame, the foundation response is carried out via Monte Carlo simulations combined with deterministic thin layer method (TLM).

The soil profile is modeled as a set of superposed layers ex- tending horizontally to infinity, and having random properties.

Spatial variability of soil properties is considered in the vertical direction only.

The analysis integrates the influence of coefficient of variation of the four soil properties on foundation response.

Obtained results indicate that shear modulus is of prime importance.

So, mass density and damping ratio variability can be neglected in a dynamic anal- ysis of a strip foundation.

The Poisson ration has a small effect on foundation response c 1 oscd resonance frequency.