Abstract

The ground motion vertical component is generally ignored in the analysis of ordinary building structures, even though observed damages after last earthquakes highlighted its marked influence especially on the response of masonry structures. In the present research work, the effect of ground motion vertical components in case of near-source excitations has been analysed. The investigation has been made on the Banloc Castle, a historical masonry building damaged by the Banat-Voiteg earthquake occurred on December 1991 in the Region of Banloc in Romania. A FEM model of the building, setup with the DIANA FEA analysis software, has been investigated in the non-linear dynamic field. In particular, the records have been referred to the Banloc site, located 7.01 km far from the epicentre with a moment magnitude Mw=5.5 and a focal depth of 9 km. The behaviour of the ground motion components has been characterised by the V/H peak ground acceleration ratio. In order to estimate the influence of the vertical seismic motion in terms of both displacements and stress regime, two different scenarios have been analysed. The first scenario has taken into account the horizontal component only, whereas the second one has analysed the simultaneous effects of three components of the seismic action. Finally, numerical damage patterns have been plotted aiming to simulate the real cracks detected in the case study after the considered seismic event.