Vulnerability of local masonry buildings to seismic loading

Abstract

The principle objective of this dissertation research study is to investigate the seismic vulnerability of existing masonry buildings with clear span underground basements in isolation under different geological conditions and subjected to the typical seismic hazards appropriate for the Maltese islands. For this purpose, Eurocode 8 and other national seismic design codes and design recommendations were used to define the appropriate seismic actions that were eventually adopted within the structural analysis and design of such buildings. Parametric seismic analyses were conducted using case studies of actual local masonry buildings having different plan layouts, sway resisting systems and overall building heights. These preliminary studies showed that local masonry buildings are susceptible to seismic effects, particularly when the lower floors are devoid of internal masonry partitions due to their use, such as for car parking. Indeed, it was found that masonry buildings up to 3 floors high and constructed on rock had sufficient lateral resistance against earthquake events corresponding to local seismic conditions. On the other hand, higher masonry buildings and/or masonry buildings constructed over weaker subsoil conditions were unlikely to survive such an earthquake event. Finally, seismic design recommendations were also proposed in order to improve the structural safety of local masonry buildings in seismic loading situations.