PRESENTATION – “Seismic Assessment of Existing Masonry Buildings”

When – Wednesday 19 February 2014

Presentation from Sergio Lagomarsino, University of Genoa (Italy)

 Abstract

Recent earthquakes in Italy have shown the high vulnerability of existing masonry buildings and the urgent need for reliable seismic assessment procedures for ensuring safety and for planning preventative interventions. Masonry buildings are subject to damage also for low-intensity earthquakes and, if connections are inadequate, local failure mechanisms can occur. However, the collapse limit state can be prevented even for medium to high intensity earthquakes, if the building has a significant displacement capacity. Therefore, nonlinear modelling is unavoidable for accurate assessment of existing buildings and can be performed by static pushover or incremental dynamic analyses.

This seminar will present modelling strategies, target performances and acceptance criteria for the seismic assessment. The displacement-based approach is adopted both for the global and the local seismic behaviour. In particular, the basic hypotheses of the TREMURI program are discussed, which is based on the discretization of masonry walls by piers and spandrel beams (equivalent frame approach). For the analysis of local failure mechanisms a macro-block approach is proposed, which is based on limit equilibrium analysis; the displacement capacity is obtained by considering geometric nonlinear effects.

The proposed procedures are validated by application to some case studies, taking also advantage of observed seismic damage and shaking table tests.