Pushover‐based seismic risk assessment and loss estimation of masonry buildings

Abstract

A pushover-based seismic risk assessment and loss estimation methodology for masonry buildings is introduced. It enables estimation of loss by various performance measures such as the probability of exceeding a designated economic loss, the expected annual loss, and the expected loss given a seismic intensity. The methodology enables the estimation of the economic loss directly from the results of structural analysis, which combines pushover analysis and incremental dynamic analysis of an equivalent SDOF model. The use of the methodology is demonstrated by means of two variants of a three-storey masonry building both of which have the same geometry, but they are built, respectively, from hollow clay masonry (model H) and solid brick masonry (model S). The probability of collapse given the selected design earthquake corresponding to a return period of 475 years was found to be negligible for model H, which indicates the proper behaviour of such a structure when designed according to the current building codes. However, the corresponding probability of collapse of model S was very high (46%). The expected total loss given the design earthquake was estimated to amount to 28 000 € and 290 000 €, respectively, for models H and S. The expected annual loss per 100 m 2 of gross floor area was estimated to amount to 75 € and 191 €, respectively, for models H and S. For the presented examples, it was also observed that nonstructural elements contributed more than 50% of the total loss. K E Y W O R D Sexpected annual loss, hollow clay masonry, loss estimation, probability of collapse, seismic risk assessment, solid brick masonry

Design Considerations for Retrofitting of Historic Masonry Structures with Externally Bonded FRP Systems

“…In the case of CFRP and GFRP (which is about 50% cheaper and for this reason presented in the paper), the cost of the retrofitting intervention depends on the price of material, the cost of implementation and additional costs (façade refurbishments, etc.). In a recent risk assessment and loss estimation study conducted by Snoj and Dolšek (2020), it was determined that for existing solid brick masonry buildings, the expected annual loss was estimated to 191 EUR per 100 m 2 of gross floor area. Effective and economically feasible seismic retrofit measures should, therefore, be adopted in order to accommodate the inherent risks, associated with this type of building typology.…”

Equivalent frame discretisation for URM façades with irregular opening layouts

“…numerically-based seismic risk studies, where a large suite of simulated responses is needed. To decrease computational burden, simplified methods, ranging from the application of limit analysis (Block et al 2006;Milani et al 2006) to story mechanism models (Braga andDolce 1982, Tomazevic 1978) and equivalent singledegree-of-freedom systems (Graziotti et al 2016;Snoj and Dolšek 2020), have been used over the years to study the structural behaviour of low-rise and regular masonry constructions subjected to either quasi-static or dynamic IP loading. Amongst others, Equivalent Frame Model (EFM)-based approaches demonstrated to represent an acceptable solution for simulating the IP nonlinear response of large-scale URM buildings.…”

Shake-table response simulation of a URM building specimen using discrete micro-models with varying degrees of detail

“…The numerical assessment of the seismic response of unreinforced masonry (URM) buildings is typically conducted using low-cost computational strategies, which allow the undertaking of a relatively large number of analyses in a reasonable timeframe. Simplified methods, ranging from the application of limit analysis (D'Ayala and Speranza 2003;Block et al 2006) to story mechanism models (Braga and Dolce 1982;Tomaževič 1987) and equivalent single-degree-of-freedom systems (Graziotti et al 2016;Snoj and Dolšek 2020), have been used over the years to study the structural behaviour of low-rise and regular masonry constructions subjected to either quasi-static or dynamic loading. Of particular interest are the latest developments in mathematical modelling and variational approaches (Portioli 2019;Cascini et al 2020), incorporating principles of both limit and discontinuous analyses, although presently mainly applied to historic and dry-joint URM constructions (see e.g.…”