scholarly journals Onsite Testing for Nonlinear Analysis of an Earthquake Damaged Historical Church in Italy

2021 ◽  
Vol 11 (24) ◽  
pp. 11755
Author(s):  
Silvia Santini ◽  
Carlo Baggio ◽  
Valerio Sabbatini ◽  
Claudio Sebastiani
Keyword(s):  
Central Italy ◽  
Research Work ◽  
Element Model ◽  
The State ◽  
Dynamic Monitoring ◽  
Global Dynamic ◽  
Central Italy Earthquake ◽  
Proof Testing ◽  
Historical Masonry ◽  
Nonlinear Static

Analysis and diagnosis of historical masonry buildings are frequently affected by uncertainties due to unexpected behaviors caused by cumulative damage, material decay or transformations. This research work follows a methodology in the structural analysis of the historical masonry church of San Filippo Neri in Macerata, severely damaged after the Central Italy Earthquake occurred in October 2016. The PRiSMa laboratory (Proof testing and Research in Structures and Materials) of Roma Tre University carried out an extensive onsite testing campaign, including NDT tests as sonic tomography and endoscopy, and minor destructive technique as double flat jack test, together with dynamic monitoring under ambient vibrations, to investigate the state of conservation of the building. The onsite testing results were then implemented in an accurate finite element model, which was tuned up by means of global dynamic response provided by OMA (operational modal analysis) and updated, after the sensitivity analysis, through the Douglas-Reid method. Finally, nonlinear static and dynamic analyses were performed to investigate the state of damage of the church and reduce its uncertainties. This methodology will support the design of strengthening measures to achieve a higher level of safety concerning both needs of protection and conservation, thereby avoiding ineffectual or amiss interventions.

Damage Assessment of San Francesco Church in Amandola Hit by Central Italy 2016-2017 Seismic Event

2019 ◽  
Vol 817 ◽  
pp. 627-633
Author(s):  
Ersilia Giordano ◽  
Angela Ferrante ◽  
Elisa Ribilotta ◽  
Francesco Clementi ◽  
Stefano Lenci
Keyword(s):  
Seismic Event ◽  
Global Analysis ◽  
Central Italy ◽  
Element Model ◽  
Constitutive Law ◽  
Nonlinear Static Analysis ◽  
Local Analysis ◽  
Marche Region ◽  
Nonlinear Static ◽  
The Church

Italy is a high seismic risk country since 1900 more than 30 earthquakes with magnitude greater than Mw=5.8 have occurred, and the last one is the Central Italy seismic sequence. The first shock occurred in the 24 August (Mw=6.2) followed by another stronger quake in the 30th October (Mw=6.5). It hit the regions of Marche, Umbria, and Abruzzo heavily causing many deaths, injuries and extensive damages on the cultural heritage. This paper analyses the church of San Francesco in Amadola, located in the Marche region that has been considered condemned for the severe damages reported after these earthquakes. The church is globally analyzed by the application of nonlinear static analysis on a Finite Element Model where the nonlinearity of masonry is taking into account with a proper constitutive law. The study wants to prove how global analysis combined by the local analysis can reproduce the behavior of this structure during a quake, showing that it can repeat the real damages produced by earthquakes.

Redesign of a dissipative bracing-based retrofit intervention for an earthquake damaged school building

2021 ◽  
Author(s):  
Gloria Terenzi ◽  
Iacopo Costoli ◽  
Stefano Sorace
Keyword(s):  
Central Italy ◽  
Time History ◽  
Element Model ◽  
Elastic Response ◽  
School Building ◽  
Structural Members ◽  
Reinforced Concrete Structure ◽  
Fluid Viscous Dampers ◽  
Central Italy Earthquake ◽  
The Finite Element Model

<p>A school building with reinforced concrete structure, seismically retrofitted in 2013 and damaged by the 2016 Central Italy earthquake, is examined in this paper. A time-history assessment analysis is initially carried out in pre-rehabilitated conditions by simulating also the presence of the clay brick masonry infill perimeter walls and partitions in the finite element model of the structure. Based on the results of this analysis, a different retrofit solution is proposed, consisting in the incorporation of dissipative braces equipped with pressurized fluid viscous dampers. The verification analyses developed in this new configuration for the main shock records of the 2016 earthquake highlight slightly damaged and easily repairable response conditions of a little number of partitions — instead of the diffused moderate-to-severe damage surveyed in the building internal and perimeter infills</p><p>— and an elastic response of structural members.</p>

scholarly journals Intervention Strategies for the Seismic Improvement of Masonry Buildings Based on FME Validation: The Case of a Terraced Building Struck by the 2016 Central Italy Earthquake

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 404
Author(s):  
Maria Rosa Valluzzi ◽  
Luca Sbrogiò ◽  
Ylenia Saretta
Keyword(s):  
Central Italy ◽  
Intervention Strategies ◽  
Masonry Walls ◽  
Masonry Buildings ◽  
Damage Pattern ◽  
Central Italy Earthquake ◽  
Kinematic Analyses ◽  
Nonlinear Static ◽  
Macro Element ◽  
Parametric Analyses

Residential masonry buildings represent a large stock among highly vulnerable structures in medium–high seismic hazard areas, often built without any anti-seismic provisions. Their rehabilitation and/or strengthening according to optimised intervention strategies is topical and may contribute to revaluating zones characterized by depopulation phenomena. In this paper, a terraced building struck by the 2016 Central Italy earthquake is analysed through a frame by macro element (FME) model. The building is composed of six two-storey units made of stone and clay block masonry walls and semi-rigid diaphragms. The numerical model was calibrated based on the damage pattern caused by the earthquake and then used to carry out parametric analyses on the strengthened conditions by simulating both one unit and the entire terrace. The effects of interventions applied to either vertical or horizontal components, both singularly and in combination, were analysed in terms of nonlinear static analyses, and quantified by a performance factor, according to the upgraded seismic code in Italy. Kinematic analyses also completed the assessment of the building. Results compared the capacity of interventions in attaining the targets defined for improvement at both local and overall levels.

scholarly journals Failure Analysis of Apennine Masonry Churches Severely Damaged during the 2016 Central Italy Seismic Sequence

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 58 ◽  
Author(s):  
Francesco Clementi
Keyword(s):  
Case Studies ◽  
Central Italy ◽  
Numerical Data ◽  
Sensitivity Study ◽  
Nonlinear Material ◽  
Seismic Sequence ◽  
Nonlinear Approach ◽  
Nonlinear Static ◽  
Masonry Churches ◽  
Global And Local

This paper presents a detailed study of the damages and collapses suffered by various masonry churches in the aftermath of the seismic sequence of Central Italy in 2016. The damages will first be analyzed and then compared with the numerical data obtained through 3D simulations with eigenfrequency and then nonlinear static analyses (i.e., pushover). The main purposes of this study are: (i) to create an adequately consistent sensitivity study on several definite case studies to obtain an insight into the role played by geometry—which is always unique when referred to churches—and by irregularities; (ii) validate or address the applicability limits of the more widespread nonlinear approach, widely recommended by the Italian Technical Regulations. Pushover analyses are conducted assuming that the masonry behaves as a nonlinear material with different tensile and compressive strengths. The consistent number of case studies investigated will show how conventional static approaches can identify, albeit in a qualitative way, the most critical macro-elements that usually trigger both global and local collapses, underlining once again how the phenomena are affected by the geometry of stones and bricks, the texture of the wall face, and irregularities in the plan and elevation and in addition to hypotheses made on the continuity between orthogonal walls.

scholarly journals Molecular Identification of New Cases of Human Dirofilariosis (Dirofilaria repens) in Italy

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 251
Author(s):  
Simona Gabrielli ◽  
Valentina Mangano ◽  
Federica Furzi ◽  
Alessandra Oliva ◽  
Serena Vita ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Central Italy ◽  
Research Work ◽  
Pulmonary Nodules ◽  
Elisa Test ◽  
Future Research ◽  
Worldwide Distribution ◽  
Human Dirofilariosis ◽  
Vector Borne ◽  
Etiological Agents

(1) Dirofilariosis is a vector-borne parasitic disease mainly in domestic and wild carnivores caused by Dirofilaria (Noctiella) repens, which is endemic in many countries of the Old World, and D. immitis, which has a worldwide distribution. In recent years, an increase in the number of human cases has been reported, suggesting that dirofilariosis is an emergent zoonosis. Here, we describe further cases (N = 8), observed in Central Italy during the years 2018–2019. (2) Molecular diagnosis was performed on: (i) live worms extracted from ocular conjunctiva, cheek, and calf muscle; (ii) histological sections of surgically removed nodules from parenchymal lung, coccyx, and breast. (3) Sequence analysis (650-bp) of the mitochondrial cytochrome oxidase subunit I gene (mtDNA cox1) showed a match of 100% with the sequences of D. repens previously deposited in GenBank. ELISA test to detect IgG against filarial antigens was performed on four patients’ sera and resulted positive in two patients who showed ocular and subcutaneous dirofilariosis, respectively. Microfilariae have been never detected in the peripheral blood of the patients. (4) The occurrence of N = 8 new cases of human D. repens-infections observed in a two-year period suggests an increased circulation of the parasite in Italy. Therefore, dirofilariosis should be included in differential diagnosis in patients presenting subcutaneous and/or pulmonary nodules. Molecular diagnosis of the etiological agents is fundamental. Specific serological diagnosis needs to be improved in future research work.

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