Comparative assessment of nonlinear static and dynamic methods for analysing building response under sequential earthquake and tsunami

Abstract

In the central region of Chile, the unreinforced masonry (URM) churches underwent extensive structural damage during the 2010 Maule earthquake (Mw 8.8), highlighting the importance of implementing seismic risk reduction plans. These religious buildings are characterized by profound typological and constructive peculiarities, originated by the combination of the local build culture with European architectural revivalisms(i.e., Neo-Baroque, Neo-Classic, Neo-Renaissance and Neo-Gothic)during the Spanish domination (1536–1818). The uniqueness of this heritage and the seismic risk of the Chilean territory lead to the need to define a systematic method to assess the seismic vulnerability of the Chilean URM churches. In this paper, some results of an in-depth investigation on a representative stock of churches are reported. The investigation was based on a database implementation with geometrical, constructive, and structural characteristics of 40 URM churches in the Metropolitan Region of Chile. A preliminary qualitative assessment of the seismic capacity of these churches is provided using a survey of geometric indices. Than specific damages observed after the 2010 earthquake have been related to the recurrent failure mechanisms of masonry structures, taking into account 21 local mechanisms involving the macro-elements of the churches. The average level of damage suffered by each church was calculated through the global damage index and a histogram of damage levels frequencies has been arranged. These results are preliminar suitable probabilistic tools to support seismic risk reduction plans.