Estimation of the seismic structural capacity of masonry buildings through simplified procedures

The seismic behavior of masonry structures, as well known, is divided into two main branches: local one, in case of lack of connections among orthogonal walls and among floors and walls, and global one, due instead to the presence of efficacious links between the structural elements. The local behavior leads to simple out-of-plane rocking or, in general, local mechanisms of facades, while the global one is related to the in-plane reactions of the resistant systems. The vulnerability assessment of masonry structures requires two different analyses for the evaluation of the capacity (often expressed in terms of PGA) of the behaviors mentioned above. In case of large samples of buildings (territorial approach), simplified preliminary methods are required for a first estimation of the capacity, in order to find a ranking useful for the definition of detailed analyses’ priority. In this work, the resume of a comparison study among empirical approaches and detailed analyses for masonry structures is described: the estimation of the PGA of capacity is proposed, both for the local and global behavior, simply using the information of the Vulnerability Index Method (GNDT, 1993).