No abstract

No abstract

The present article highlights the beneficial effect of considering soil and structure parameters uncertainties on the soil-structure response. The impedance functions of a circular foundation resting on a random soil layer over a homogeneous half-space were obtained by using cone models. The obtained results showed that the randomness of the layer's thickness and the shear wave velocity significantly affected the mean spring coefficients whereby coefficients of variation (COV) of 10% and 20% in these parameters reduced the mean spring coefficients about 32% and 40%, respectively, for the horizontal motion and about 12.5% and 25%, respectively, for the rocking motion. The sensitivity of the mean structural response to the randomness effect was obtained to be more pronounced to structural parameters than to soil parameters. In addition, 20% COV in both soil and structure parameters reduced the mean structural response about 39%, translated by an increase in the damping of the coupled system which may be considered as a beneficial effect from code provisions point of view.

The aim of this study is to consider the effects of the variation of shear modulus ratio (G/G0) and damping ratio (ξ) of soil, obtained by a linear iterative method based on the design spectra of seismic codes, the soil environment in terms of uncertainties in shear modulus using Monte Carlo simulations and the foundation damping (ξf) of flexible base for analyses of the Soil-Structure Interaction (SSI) problems. A squat structure with circular shallow foundation resting on a soil layer over a homogeneous half-space is studied by using cone model and considering seismic zone effect on structural response. Firstly, after showing the effects of the correction of G and ξ on impedance functions and the responses of soil-foundation-structure system, a study is carried out to compare these effects to those of the modelling of uncertainties in shear modulus as random variations. Secondly, a comparative analysis on design response spectra and base shear forces was carried out for four seismic codes (Algerian Seismic Rules RPA99-2003, Eurocode 8–2004, International Building Code IBC-2015 and Indian Code IS-1893-2002) considering the three cases of SSI: SSI effects (initial G and ξ), nonlinear SSI (corrected G and ξ) and stochastic SSI (random G with COV = 20%) compared to the fixed base case. Results show that the correction of G and ξ, according to the equivalent nonlinear method in all the cases, leads to a remarkable decrease in peak responses but show a huge amount of reduction in the second study for IBC-2015 and IS-1893-2002 codes compared to the other codes.

No abstract