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

In the last years, several catastrophic tsunami events 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 buildings typologies. This paper aims to assess the vulnerability of masonry buildings under tsunami loads by means of the minimum inundation depth triggering a failure mechanism coherently with a large scale approach and consequentially, a low knowledge level achieved on properties of structures. Furthermore, out-of-plane and in-plane mechanisms activation is investigated by modelling an external tsunami load pattern with simplified assumptions. Shear and flexural failure are analysed as main in-plane failure modes while horizontal and vertical bending mechanisms are considered as main out-of-plane failure modes. Masonry walls are modelled as frame elements and masonry is modelled as a nonlinear material. Japanese guidelines are assumed to model tsunami loads instead of more refined models, such as ASCE 7-16 and FEMA P-646 proposals, due to reduced achievable knowledge level. Proposed mechanical models provide important information about vulnerability of masonry buildings under tsunami loads and they represent a basic step to provide vulnerability information on masonry buildings at a regional scale level.