Abstract

Failure of masonry structures during earthquakes often occurs via specific, well- documented collapse mechanisms, many of which involve partial collapse of the structure well above ground level. Consequently, the elastic response of the structure needs to be considered, which in the case of historic structures such as bell towers and churches often requires modal analysis using finite element models - the generation of which can be labour-intensive and time- consuming. This paper presents a new integrated modeling approach which combines finite element analysis with rocking dynamics in order to model the seismic response of complex structural geometries in a computationally-efficient manner. The modeling strategy is implemented within COMPAS - an open-source computational framework that provides geometry processing independent of CAD software, and is incorporated within the broader framework of a tool being developed for the seismic collapse assessment of masonry structures. The framework of this new tool is first outlined, and the utility of the new modeling approach then demonstrated through application to the seismic assessment of a historic masonry tower in North-Eastern Italy. The analysis results indicate that for the level of seismic hazard expected on site, failure of the tower is most likely to occur via overturning collapse of one of the rampart elements. The importance of accounting for elastic amplification effects, as well as the influence of varying boundary conditions on the dynamic response, is also demonstrated.