Surface topography and site stratigraphy effects on the seismic response of a slope in the Achaia-Ilia (Greece) 2008 Mw6.4 earthquake

Following an overview of the state of knowledge on the effects of slope topography on the seismic ground response, the results of numerical analyses of the response of a 28° slope, with a height of 24 m, located in the meizoseismal area of the Achaia-Ilia (Greece) 2008 Mw6.4 earthquake, are presented. The 2-D and 1-D FEM equivalent-linear analyses were based on the results of an extensive geotechnical investigation and on input motions estimated on the basis of recorded acceleration time histories in the broader area of the slope. The results of analyses were (a) found to be in a good agreement with the observed distribution of structural damages in the area of the town, (b) used to separate the effects of pure topography from the effects of soil stratigraphy, and (c) used to check the validity of a simplified prediction of topography effects, by superimposing the decoupled 1-D and 2-D amplification of motions.