Seismic Vulnerability of Italian Historical Towns: The Case of Borgo San Rocco

2021 ◽  
Vol 109 ◽  
pp. 1-7
Author(s):  
Valentina Cima ◽  
Valentina Tomei ◽  
Ernesto Grande ◽  
Maura Imbimbo

The assessment of the seismic safety level of masonry buildings is a current and important issue at the basis of the complex process of preservation of historical masonry buildings which constitute mostly the Italian and European towns. Nowadays, different approaches able to provide important information concerning the seismic safety level of masonry structures are available. Among these, fragility curves allow to have a prediction of potential damages during an earthquake of geographical areas characterized by similar construction typologies. The present paper concerns the derivation of fragility curves of masonry buildings, typical of Italian historical towns and mainly characterized by the possible occurrence of local out-of-plane collapse mechanisms. To this end, a real case is accounted in the study in order to consider specific parameters characterizing the constructions composing these territorial realities.

2021 ◽  
Vol 898 ◽  
pp. 1-7
Author(s):  
Ingrid Boem ◽  
Natalino Gattesco

Historic masonry buildings experience a high seismic vulnerability: innovative intervention strategies for strengthening, based on the use of fibre-based composite materials are gradually spreading. In particular, the coupling of fibre-based materials with mortar layers (Fibre Reinforced Mortar technique - FRM) evidenced a good chemical and mechanical compatibility with the historical masonry and proved to be effective for the enhancement of both in-plane and out-of-plane performances of masonry, contrasting the opening of cracks and improving both resistance and ductility. The resistant mechanisms that arise in FRM strengthened masonry walls subjected to in-plane horizontal actions are analyzed in the paper and a practical design approach to evaluate their performances is illustrated, evidencing the dominant collapse mode at the varying of the masonry characteristics. Some masonry walls are analyzed numerically and analytically, as “case study”.


2021 ◽  
Vol 11 (5) ◽  
pp. 2280
Author(s):  
Igor Tomić ◽  
Francesco Vanin ◽  
Katrin Beyer

Seismic assessments of historical masonry buildings are affected by several sources of epistemic uncertainty. These are mainly the material and the modelling parameters and the displacement capacity of the elements. Additional sources of uncertainty lie in the non-linear connections, such as wall-to-wall and floor-to-wall connections. Latin Hypercube Sampling was performed to create 400 sets of 11 material and modelling parameters. The proposed approach is applied to historical stone masonry buildings with timber floors, which are modelled by an equivalent frame approach using a newly developed macroelement accounting for both in-plane and out-of-plane failure. Each building is modelled first with out-of-plane behaviour enabled and non-linear connections, and then with out-of-plane behaviour disabled and rigid connections. For each model and set of parameters, incremental dynamic analyses are performed until building failure and seismic fragility curves derived. The key material and modelling parameters influencing the performance of the buildings are determined based on the peak ground acceleration at failure, type of failure and failure location. This study finds that the predicted PGA at failure and the failure mode and location is as sensitive to the properties of the non-linear connections as to the material and displacement capacity parameters, indicating that analyses must account for this uncertainty to accurately assess the in-plane and out-of-plane failure modes of historical masonry buildings. It also shows that modelling the out-of-plane behaviour produces a significant impact on the seismic fragility curves.


Author(s):  
A. Sandoli ◽  
G. P. Lignola ◽  
B. Calderoni ◽  
A. Prota

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.


2017 ◽  
Vol 4 ◽  
pp. 24-30
Author(s):  
Shyam Sundar Basukala ◽  
Prem Nath Maskey

Historic buildings of Nepal are mainly constructed from masonry structure. Since masonry structures are weak in tension which leads to the failure of structure. So, to avoid possible damage in environment lives and property it is urgent to conduct vulnerability assessments. Seismic vulnerability of historic masonry buildings constructed in Bhaktapur at Byasi area is carried out for the case study. Five load bearing masonry buildings were selected out of 147 buildings considering opening percentage, storey and type of floor for modeling in SAP 2000 V10 Various methods of rapid visual screening (FEMA 154, EMS 98) are used to determine the vulnerability of the selected building. The Selected Building response is carried out by linear time history analysis. The seismic vulnerability of masonry structures is determined in terms of fragility curves which represent the probability of failure or damage due to various levels of strong ground motions for different damage state slight, moderate, extensive and collapse. From the result of Rapid Visual Screening (RVS) and Fragility curves of the buildings it is found that whole, buildings are found vulnerable from future earthquake.


2021 ◽  
Author(s):  
Antonio Sandoli ◽  
Gian Piero Lignola ◽  
Bruno Calderoni ◽  
Andrea Prota

Abstract A hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions.Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure (IM) to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minim value of PGAs defined for each buildings class.To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber (MCS) macroseismic intensity scale has been used and the corresponding fragility curves developed.Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.


2009 ◽  
Vol 25 (2) ◽  
pp. 323-346 ◽  
Author(s):  
Sergio Lagomarsino ◽  
Sonia Resemini

The structural safety evaluation of monumental and historical buildings in seismic prone areas requires the availability of appropriate verification tools, in order to ensure both a realistic estimation and the feasibility of the method. In the case of historical masonry structures, such as palaces or churches, local damage mechanisms often take place (e.g., out-of-plane overturning). A procedure to assess the seismic vulnerability of these mechanisms, focusing on the damage limitation state, is developed through equilibrium limit analysis. Moreover, the possibility of enriching the formulation, including constructive and technological aspects, which may modify structural response, is shown.


2012 ◽  
Vol 28 (2) ◽  
pp. 759-794 ◽  
Author(s):  
Nicola Tarque ◽  
Helen Crowley ◽  
Rui Pinho ◽  
Humberto Varum

The seismic vulnerability of single-story adobe dwellings located in Cusco, Peru, is studied based on a mechanics-based procedure, which considers the analysis of in-plane and out-of-plane failure mechanisms of walls. The capacity of each dwelling is expressed as a function of its displacement capacity and period of vibration and is evaluated for different limit states to damage. The seismic demand has been obtained from several displacement response spectral shapes. From the comparison of the capacity with the demand, probabilities of limit state exceedance have been obtained for different PGA values. The results indicate that fragility curves in terms of PGA are strongly influenced by the response spectrum shape; however, this is not the case for the derivation of fragility curves in terms of limit state spectral displacement. Finally, fragility curves for dwellings located in Pisco, Peru, were computed and the probabilities of limit state exceedance were compared with the data obtained from the 2007 Peruvian earthquake.


2008 ◽  
Vol 30 (8) ◽  
pp. 2223-2241 ◽  
Author(s):  
Vincenzo Mallardo ◽  
Roberto Malvezzi ◽  
Enrico Milani ◽  
Gabriele Milani

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