Non-linear static analysis of masonry buildings under seismic actions

Assessing existing masonry building in seismic zones is a critical issue, due to the high vulnerability of the built environment. Commonly, beside local analysis, refined assessment procedures are used based on non linear static methods, like the pushover method, supplemented, if necessary, by dynamic linear analyses, devoted to check the order of magnitude of the results. In non-linear static analysis masonry buildings are mostly modelled using the so-called equivalent frame model, but the resulting structural scheme is usually very complicted and the analysis requires to be "driven" step by step by very skilled users in order to obtain consistent results. An innovative and "robust" method is proposed for non-linear static analysis of masonry building. The method, which relies on very simple structural models, nearly independent on the user, recovers some basic assumptions of the classical POR method, and can be applied to mono or multi-story masonry buildings. Comparing the results obtained with the proposed method with those derived using the classical pushover analysis in several relevant case studies, allowed to validate it. Moreover, the practical applications confirmed that the method is suitable for refined assessment of the seismic performance of the structure, with a limited computational effort, so making possible also extensive sensitivity studies.