Vulnerability of Soil Slopes Against Seismic Damage Based on the Effect of Spatial Variability of Soil Properties on the Development of Permanent Seismic Displacements

Abstract

Themost accurate estimation of seismic slope stability is one of the mostimportant areas of geotechnical seismic engineering. The assumption that soilconsists of layers with some average values ​​for soil parameters of each layeris not a realistic representation of actual conditions. The properties of asoil layer are not spatially invariant and the scale of changes cansignificantly affect the stability analysis of slopes. It is important toinclude in the analysis as many kinds of uncertainty, especially thoseresulting from the properties of soil mass and influencing the seismicstability of slopes.Stochastic methods have been introduced in order tocalculate the uncertainty and spatial variability of soil parameters. Recentresearch took into account the spatial variation of parameters using the RandomField Theory. In theory, these variables exhibit autocorrelation, a trend inwhich the soil properties of a point appear to be correlated with theproperties of neighbouring soil points (Vanmarcke, 1977). This study explores the influence of spatialvariability of soil properties on the development of permanent displacementsduring seismic vibration of the slopes as well as the levels of seismic damagethat can be caused. This effect is initially investigated for a fixed value ofthe maximum acceleration of the excitation, and then the results are expandedto include the effect of the seismic intensity level. The results show thecurves of vulnerability of slopes against seismic damage and constitute apretty useful tool for the design of slopes, taking performativity intoaccount.