The paper presents the results of shaking table tests carried out on masonry systems (scaled 1:1) strengthened by energy absorption devices designed to improve the out of plane response. Outcomes are fairly satisfactory, with reference to available ductility and damage control provided by the selected devices
This paper is available in Italian only.
Risk analyses always involve uncertainty which depends on the knowledge analysts have of the phenomenon they are dealing with. So, in order to use risk analyses results in a more transparent, aware and justified way, it is important to characterize and quantify this uncertainty. Unfortunately, in the field of natural risks, present analyses are mainly deterministic and do not allow uncertainty representation. The aim of this study is then proposing and testing Monte Carlo methods, which have already been adopted in other research fields, as tool for probabilistic risk analyses. In particular, the suggested method develops the seismic «Renewal Process» in a new methodology which allows to quantify and characterize both input and output parameters uncertainty. A case study, regarding the Garfagnana region, has validated the methodology. The added value of the proposed method is its transferability in the analyses of other natural hazards
This paper is available in Italian only.
The seismic response of existent buildings can be conveniently performed using dynamic methods. This kind of methodology implies a reliable calculation pattern which is validated by dynamic tests on the structure. In this paper a specific analysis of a strategic masonry building – a civil hospital in Rome – is proposed. All the experimental tests were carried out on the structure without altering the functionality of the building, which was always in full operation during the tests.
This paper is available in Italian only.
In this paper a general method is given to evaluate the collapse seismic load of existing masonry buildings. The method is based on numerical analyses in which both linear and nonlinear models are used to evaluate the seismic response of the masonry assemblage. The structure is first idealized by a F.E. model to investigate the stress patterns produced by the static loads, then a simplified nonlinear dynamic model is used to predict the collapse seismic load. In addition, the F.E. model is useful to identify some mechanical parameters of the masonry and to establish the accuracy of the simplified approach. To this aim the first two modal shapes of the building are used. To exemplify the general methodology here discussed an application is presented for Villa Faule, to be found in the Tuscany countryside in the neighborhood of Colle di Val d’Elsa (Siena). The Villa Faule was built at the end of XVIII century and is representative of many similar country houses located in the same geographic zone. Considering the dilapidated state of the walls, of the timber floor slabs and of other architectural elements, in recent times a design was approved to strengthen and to rehabilitate the building. The subject of this study is the strengthened building because the large-scale numerical models are more reliable for such types of structures. The results showed that both the procedures were useful to investigate the structural problem. The F.E. model furnished a good prediction of the masonry stresses under vertical loads and predicted the modal shapes of the structure; at the same time it revealed that the simplified model was accurate. The nonlinear simplified method gave a prediction of the seismic ground acceleration intensity to be applied to achieve the building collapse. To this purpose the structure was subjected to the N-S acceleration record of El-Centro (Imperial Valley’s earthquake, 1940). The results showed that the value of the collapse peak ground acceleration was equal or more than 2.75 m/s2.
This paper is available in Italian only.