Influence of ground motion characteristics on monumental building damage: the 2002 Molise earthqauke (Southern Italy)

Abstract

This paper presents the results of different numerical analyses (nonlinear dynamic FEM simulations) regarding the monumental buildings in Ripabottoni village (Campobasso, southern Italy), which were damaged by the 2002 Molise earthquake. In particular, the church of S. Maria Assunta, for which typological data and an exhaustive damage survey are available, is taken into account. Some preliminary studies [Spallarossa et al., 2004], which correlate the waveform of the available recordings from aftershocks and the surveyed damage mechanism (due to the crushing of the vertical structural elements), suggested that a feasible explanation for this particular damage pattern does not involve only the intrinsic vulnerability of this type of buildings, but deals also with the high energy content in the high frequency range observed in the vertical component of the seismic events. In order to understand the structural damage patterns surveyed, synthetic accelerograms, representative of the main shock (Ml = 5.4 on 31 October 2002), were computed. The Empirical Green Function (EGF) method was applied to compute the seismic input adopted in the nonlinear dynamic analyses that we performed for the church of S. Maria Assunta. The results confirm that the observed damage pattern cannot totally be put down to the vulnerability of the building, but the particular characteristics of the seismic action played a fundamental role in determining it.