Seismic vulnerability assessment for historical masonry aggregates

In this contribute, the authors propose a comprehensive limit analysis approach based on consolidated and innovative techniques for the exact identification of local mechanisms in masonry aggregates. On a three-dimensional (3D) model of the whole aggregate both pre-assigned mechanisms (CINE) and adaptive meshes (NURBS) are used. The computation of the horizontal load multiplier is carried out through the application of the Principle of Virtual Powers with a classic upper bound point of view. The analysis results show that, compared with the simple overturning collapse mechanism, the other collapse mechanisms are only activated under specific stress conditions. Some typical walls are selected to have an insight into the possibilities and limitations of the procedure proposed