Simplified approach to assess the vulnerability of masonry buildings under tsunami loads

Several catastrophic tsunami events in recent years have engaged scientific awareness to assess the tsunami risk. Fragility curves are required to analyse the vulnerability of masonry buildings and analytical fragility curves should be based on local building typologies. The aim of this study was to assess the vulnerability of masonry buildings under tsunami loads by means of the minimum inundation depth to trigger a failure mechanism. This was done using a large-scale approach and with a low knowledge level of the properties of structures. The activation of out-of-plane and in-plane mechanisms was investigated by modelling an external tsunami load pattern using simplified assumptions. Shear and flexural failure were analysed as the main in-plane failure modes while horizontal and vertical bending mechanisms were considered as the main out-of-plane failure modes. Masonry walls were modelled as frame elements and the masonry was modelled as a non-linear material. Japanese guidelines were assumed for modelling tsunami loads instead of more refined models such as those in ASCE 7-16 and Fema P-646, due to the reduced achievable knowledge level. The proposed mechanical models provide important information about the vulnerability of masonry buildings under tsunami loads and represent a basic step to provide vulnerability information on masonry buildings on a regional scale.