Local- and global-scale seismic analyses of historical masonry compounds in San Pio delle Camere (L`Aquila, Italy)

Masonry building aggregates are large parts of the Italian building heritage often designed without respecting seismic criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behaviour. For this reason, in this paper firstly, a simple methodology to forecast the seismic response of masonry aggregates in San Pio delle Camere (L’Aquila, Italy) has been set up starting from the provisions of the Italian Guidelines on Cultural Heritage. The implemented procedure has been calibrated on the results of two FEM structural analysis programs used to investigate three masonry building compounds. As a result, a design chart used to correctly predict the base shear of aggregate masonry units starting from code provisions has been set up. Later on, the large-scale seismic vulnerability and damage appraisal of the inspected historical centre has been done on the basis of a quick methodology, already implemented and experienced by the author in some historical centres of the Campania region. The analysis result was a numerical correlation between vulnerability index and mean damage grade of examined building compounds. In particular, a damage forecast under numerical way has been firstly estimated and then compared with the real one. The post-earthquake scenario has represented an ideal term of comparison for effectively testing the reliability of the employed technique, which should be further extended to other Italian historical centres

Theoretical and Numerical Seismic Analysis of Masonry Building Aggregates: Case Studies in San Pio Delle Camere (L’Aquila, Italy)

Masonry building aggregates are large parts of the Italian building heritage often designed without respecting seismic criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behavior. For this reason, in this article a simple methodology to forecast the masonry aggregate seismic response has been set up. The implemented procedure has been calibrated on the results of two FEM structural analysis programs used to investigate three masonry building compounds. As a result, a design chart used to correctly predict the base shear of aggregate masonry units starting from code provisions has been set up

Seismic damage assessment of school buildings after 2012 Emilia Romagna earthquake

In the paper the usability checks performed on precast RC gyms and masonry school buildings, located in the Municipalities of San Pietro in Casale (BO), Bomporto (MO) and Bondeno (FE) after the seismic events occurred on 2012 May 20th and 29th, are reported and discussed. First, the main features of surveyed buildings have been identified. Later on, on the basis of the detected damages, their seismic deficiencies have been recognized. Finally, the indication of some appropriate simple interventions for retrofitting studied buildings has been given

Numerical prediction of the non-linear behaviour of perforated metal shear panels

Steel plate shear walls (SPSWs) are innovative systems able to confer to either new or existing structures a significant capacity to resist earthquake and wind loads. Many tests have shown that these devices may exhibit high strength, initial stiffness and ductility, as well as an excellent ability to dissipate energy. When full SPSWs are used as bracing devices of buildings, they may induce excessive stresses in the surrounding main structure where they are inserted, so to require the adoption of large cross section profiles. For this reason, perforated steel panels, which are weakened by holes aiming at limiting the actions transmitted to the surrounding frame members, represent a valid alternative to full panels. In this work, aiming at showing the advantages of such devices, a FEM model of perforated panels has been calibrated on the basis of recent experimental tests. Subsequently, a parametric FEM analysis on different series of perforated panels, by changing the number and diameter of the holes, the plate thickness and the metal material, has been carried out. Finally, the achieved numerical results have been used to set up design charts to correctly estimate the strength and stiffness of perforated metal shear panels

Simplified and refined methods for seismic vulnerability assessment and retrofitting of an Italian cultural heritage masonry building

In the paper the usability check and the seismic vulnerability appraisement and repairing of a masonry building with cultural and artistic value located in the Municipality of Cento (Ferrara, Italy) after the last Italian seismic events (Emilia-Romagna, 2012 May 20th and 29th), are reported and discussed. After some indications on the mentioned earthquakes are given, the case study has been presented and useful information on both historical news and geometrical properties have been given. So, the usability check of examined building has been done through the identification of damages occurred under earthquake. Later on, seismic vulnerability assessment of the building on the basis of both the simplified LV1 and the refined LV3 analysis levels given by Italian Guidelines on Cultural Heritage has been performed. The analysis results, compared each other in terms of seismic safety factors, have shown that building has an average vulnerability degree, so to require local repairing and strengthening interventions, which have been herein presented. Finally, the effectiveness of the proposed local interventions has been proved by numerical analysis in the non-linear field

Editorial: Seismic Analysis and Retrofitting of Historical Buildings

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Simplified and Refined Analyses for Seismic Investigation of Historical Masonry Clusters: Comparison of Results and Influence of the Structural Units Position

The goal of this work is the seismic vulnerability assessment of building aggregates within the historical centre of Arsita (Teramo, Italy), damaged by the 2009 L'Aquila earthquake, by comparing two different analysis procedures applied to a construction compound case study. First, the seismic vulnerability of structural units of the building compound, has been appraised by using a vulnerability evaluation quick form appropriately conceived for masonry aggregates. In particular, heading and intermediate structural units, having different geometrical configuration and seismic behaviour, have been inspected by using the before mentioned form, which allowed to calculate for them a synthetic vulnerability index. Starting from these indexes, the probable damages suffered by the examined structural units under different grade earthquakes have been estimated. Later on, both the single structural units and the whole construction compound have been modelled by using the macro-element refined method foreseen by the 3Muri non-linear analysis software. Static non-linear analyses performed on the above-mentioned structures have provided the related pushover curves, used to estimate, through the N2 method, the damages suffered under seismic actions expected in that site. Therefore, damages of single structural units have been compared to those experienced by the same structures within the building aggregate. Finally, the results deriving from the two analysis methodologies considered have been compared to each other, allowing to confirm the effectiveness of the simplest technique to predict the seismic damage and vulnerability of investigated structures

On the selection by MCDM methods of the optimal system for seismic retrofitting and vertical addition of existing buildings

In the current paper a novel procedure to select the optimal solution both for seismic retrofitting of existing RC buildings and for super-elevation of existing masonry constructions has been implemented by using three different Multi-Criteria Decision Making (MCDM) (TOPSIS, ELECTRE and VIKOR) methods. The procedure application has been faced with reference to two case studies. The first intervention has been studied on a real full-scale 3D RC structure retrofitted with different seismic protection devices mainly based on metal materials, whose performances were experimentally evaluated in a previous research project. All the applied MCDM methods have provided the same result, that is the dominating role exerted by aluminium shear panels for seismic retrofitting of the analysed structure. On the other hand, different innovative and traditional constructive systems have been examined to increase the number of floors of existing masonry buildings. The effectiveness of these interventions in improving the base building behaviour has been proved on a typical building of the South Italy. The study results, achieved by using the three MCDM methods inspected, have provided as an optimal solution the cold-formed steel systems thanks to their prerequisites of lightness, economy and sustainability

Large scale seismic vulnerability and risk evaluation of a masonry churches sample in the historical centre of Naples

This paper investigates about the seismic vulnerability and risk of fifteen masonry churches located in the historical centre of Naples. The used analysis method is derived from a procedure already implemented by the University of Basilicata on the churches of Matera. In order to evaluate for the study area the seismic vulnerability and hazard indexes of selected churches, the use of appropriate technical survey forms is done. Data obtained from applying the employed procedure allow for both plotting of vulnerability maps and providing seismic risk indicators of all churches. The comparison among the indexes achieved allows for the evaluation of the health state of inspected churches so to program a priority scale in performing future retrofitting interventions