NON-DIMENSIONAL SITE AMPLIFICATION FUNCTIONS FOR BASIN EDGE EFFECTS ON SEISMIC GROUND MOTION

ABSTRACT – We have investigated basin edge effects on the seismic amplification of ground motion, with the objective to derive simple criteria useful for engineering purposes and to support studies for the possible introduction of complex (2D) site effects on design spectra. The procedure has involved the following steps: (i) available analytical solutions for SH wave propagation in simple basin-like configurations were considered; (ii) the response in the frequency domain was investigated in terms of non-dimensional parameters; (iii) a set of non-dimensional 2D/1D aggravation factors on response spectra was derived, based on convolution of the analytical transfer functions with real accelerograms from earthquakes with magnitude ranging from 5.3 to 6.5; (iv) the average 2D/1D curves were tested with the results of independent numerical simulations: an example of these comparisons has been shown, referring to the M5.9, 1995 Dinar earthquake, Turkey