Evaluation of Slope Performance under Earthquake Loading Conditions

The response of slopes to earthquake loading may be studied via effective stress dynamic analyses, displacement-based sliding block analyses or through force-based pseudo-static methods, the latter being the most widespread method used in common practice. In the pseudo-static approach, an equivalent seismic coefficient k is used within a conventional limit equilibrium slope stability analysis. Since k designates the static horizontal force to be used in the calculations, its selection is crucial for stability assessment. In the paper, equivalent seismic coefficients are evaluated relating the ground motion amplitude to earthquake-induced slope displacements using a database of Italian strong-motion records. Influence of soil deformability, that results in spatial variation of the seismic motion within the slope, is also evaluated through bi-dimensional seismic response analyses.