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Sara Paganoni

Bio: Sara Paganoni is an academic researcher from University of Bath. The author has contributed to research in topics: Masonry & Earthquake engineering. The author has an hindex of 5, co-authored 16 publications receiving 356 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the authors describe the output of a survey carried out in the district of L'Aquila, Italy, in May 2009 after the April earthquake and later in January 2010, and the consequent vulnerability assessment completed by the authors.
Abstract: The paper describes the output of a survey carried out in the district of L’Aquila, Italy, in May 2009 after the April earthquake and later in January 2010, and the consequent vulnerability assessment completed by the authors. Observations collected on site regard masonry buildings of the historic centre of L’Aquila and the towns of Paganica and Onna; particular focus was given to a number of buildings of interest, which better represent two locally recurrent building typologies: the mansion and the common dwelling. A description of the main structural features and their influence on damage mechanism is provided, stressing the importance of elements such as wall lay-out, quality of masonry and strengthening interventions. The gathered information is used as input for the application of the FaMIVE method (D’Ayala and Speranza in Earthq Spectra 19(3):479–509, 2003), whereby feasible collapse mechanisms and the associate failure load factors can be identified. The procedure is briefly outlined and results are discussed from the point of view of the performance point: push-over curves produced by statistical elaboration of FaMIVE’s output are compared both with the demand spectra obtained from EC8 and the response spectrum for the main shock as recorded by the closest station to the town. Conclusions are drawn on the reliability of the FaMIVE method with respect to its capability of predicting the damage mechanism identified on site.

283 citations

Journal ArticleDOI
TL;DR: In this paper, the authors carried out two sets of laboratory tests on masonry samples strengthened by metallic grouted anchors and developed a design procedure to evaluate the performance of the connection, both in the unreinforced and strengthened set up.

55 citations

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TL;DR: In this paper, the authors describe the observations made by a reconnaissance team following the 22nd February 2011, Mw 6.3, Christchurch, New Zealand earthquake (GNS Science, 2011).
Abstract: This paper describes the observations made by a reconnaissance team following the 22nd February 2011, Mw 6.3, Christchurch, New Zealand earthquake (GNS Science, 2011). The team comprised of members of the UK based Earthquake Engineering Field Investigation Team who spent 5 days collecting observations on damage resulting from the earthquake. Although the magnitude of this earthquake was not particularly high (Mw 6.3), the shallow focus and close proximity resulted in locally very high ground motions, widespread damage and 182 fatalities. The earthquake is also particularly notable for the widespread liquefaction it caused, landslides and rockfalls in the hills south of Christchurch, and the significant damage suffered by unreinforced masonry and historic structures. Over wide areas of central Christchurch, recorded accelerations were in excess of those required by the current New Zealand seismic loadings standard (NZS1170.5:2004: Standards New Zealand 2004) and therefore the earthquake presented a valuable opportunity to assess performance of modern buildings under code-level ground acceleration.

35 citations

Journal ArticleDOI
01 Jan 2014
TL;DR: In this article, two dissipative devices are developed to restore the connection between perpendicular masonry walls and to control relative displacements, thus reducing the load stress resultants transmitted to the substratum and the risk of pull-out or punching failures.
Abstract: During the past few decades, various technical solutions have been developed to improve the seismic performance of structural connections, as these determine the global response of buildings as much as single structural elements. However, in the case of heritage buildings, standard strengthening systems might have collateral effects owing to their high stiffness in comparison with historic substrata. Furthermore, little technical guidance is given to designers for dimensioning the retrofit of connections. Drawing on these observations, the authors have developed, in collaboration with Cintec Ltd, two dissipative devices. These are able to restore the connection between perpendicular masonry walls and to control relative displacements, thus reducing the load stress resultants transmitted to the substratum and the risk of pull-out or punching failures. The paper gives an overview of the experimental work conducted to identify performance parameters and exemplifies how these can be used for designing the str...

13 citations

Journal ArticleDOI
TL;DR: In this article, the authors have developed two typologies of dissipative devices that can be integrated in traditional steel anchors and installed within the masonry at the joints of perpendicular walls, where out-of-plane mechanisms are likely to form due to poor quality connections.
Abstract: Since earthquakes such as Northbridge (1994) and Kobe (1995) gave the impetuous for the development of performance-based design methods, engineers have been strenuously working to the improvement of the seismic behaviour of structures; in fact, high ductility frames, as well as damping and isolation systems, are nowadays common practice in seismic prone areas. Heritage buildings constitute an odd case: many historic centres are still considerably affected by seismic events (L’Aquila, 2009) due to the lack of a methodical retrofit and this, where applied, is still largely based on the increase of stiffness and capacity, without the due care for precious finishings. In order to address the lack of specific passive systems for heritage buildings, the authors have developed two typologies of dissipative devices that can be integrated in traditional steel anchors and installed within the masonry at the joints of perpendicular walls, where out-of-plane mechanisms are likely to form due to poor quality connections. Both prototypes, one based on the plasticity of steel, the other relying on friction, were tested as isolated elements in pseudo-static regime for proofing and fine tuning, and in a dynamic range typical of the seismic frequency content to validate the stability of dissipative loops. The paper focuses on pull-out tests aimed to analyse the behaviour of the hysteretic prototype in respect to traditional steel anchors in masonry panels with low shear capacity. Finite Element (FE) models were also developed and calibrated applying the data from tests. Experimental and computational results are discussed in the following; the need for further theoretical work concludes the paper.

10 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the performance of common architectural configurations, typical for residential or business use, was evaluated for repeated shaking in low-rise masonry buildings, with PGA as large as 0.25-0.3.
Abstract: The earthquake sequence started on May $$20$$ th 2012 in Emilia (Italy) affected a region where masonry constructions represent a large part of the existing building stock and the construction of new modern masonry buildings is a common practice. The paper is focused on the performance of common architectural configurations, typical for residential or business use. The large majority of old masonry buildings is made of fired clay bricks. The seismic performance of these buildings is particularly interesting since major past earthquakes in Italy affected areas with mainly stone masonry structures. Apart from examples showing systematic or peculiar structural deficiencies governing the vulnerability of several buildings, the overall seismic performance of these structures to repeated shaking, with PGA as large as 0.25–0.3 g was rather good, despite the major part of them were only conceived for carrying vertical loads. In fact, seismic design is mandatory in the area only since 2003. Modern low-rise masonry buildings erected after this date and incorporating seismic design and proper detailing resulted in most cases practically undamaged. The examples reported in the paper allow an evaluation of the superior performance of seismically designed modern masonry buildings in comparison to older ones.

231 citations

Journal ArticleDOI
TL;DR: In this article, the seismic behavior of masonry churches damaged during the 2009 L’Aquila earthquake is studied, and four important basilicas are considered in order to derive general conclusions from the damage assessment and the performance analysis.

184 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the specific vulnerability factors and construction features of unreinforced masonry buildings in the affected area, in particular in the area between Amatrice and Arquata del Tronto.
Abstract: Between August 2016 and January 2017 nine shallow earthquakes ranging from 5.0 and 6.5 of moment magnitude affected Central Italy, involving several municipalities wherein unreinforced masonry buildings are more than three quarters of all constructions. Damage state has been very severe, with sixteen settlements belonging to the municipalities of Amatrice, Arquata del Tronto, Accumoli, Castelsantangelo sul Nera and Norcia experiencing a cumulative European macroseismic scale intensity larger than IX. Ground motion demand in terms of peak ground velocity was approximately two or three times what expected for a 475 years return period while the pseudoacceleration response spectra showed values between once and twice gravity acceleration for the period range typical of two and three storeys unreinforced masonry buildings. Moreover, since October 2016, such large seismic demand acted on structures damaged from previous shocks testifying the effects of damage accumulation, too. The significant shaking alone cannot explain the extremely severe damage of some settlements, with large portions of whole blocks completely collapsed, highlighting the need for investigating the specific vulnerability factors and construction features of unreinforced masonry buildings in the affected area. In fact, although some deficiencies already highlighted in previous Italian earthquakes (e.g. inadequate structural connections) have been surveyed also during this sequence, a marked vulnerability of masonry and its mortar has been noticed, in particular in the area between Amatrice and Arquata del Tronto. On the contrary, the historical constructions in Norcia performed much better, as a result of the 1860 seismic code and of the retrofitting interventions implemented after the different earthquakes occurred in the last two centuries. Finally, a number of demolished and rebuilt constructions performed very well, and this was also the case also of modern hollow clay blockwork buildings that protected not only human life, but also cost of construction and continuity of use.

174 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the vulnerability of cultural heritage, with particular reference to churches, in the case of the L’Aquila earthquake and found that the bad behaviour of churches strengthened by modern techniques, such as the substitution of original timber roofs with stiff and heavy r.c. slabs, was observed.
Abstract: L’Aquila earthquake, which occurred on April 6, 2009, proved the high vulnerability of cultural heritage, with particular reference to churches. Damage assessment in the emergency was carried out on more than 700 churches with a methodology aimed at recognizing the collapse mechanisms in the different architectonic elements of the church. The method was developed after the earthquake in Umbria and the Marches (1997) and has been widely used in the last decade; this approach is also very useful for seismic prevention, as it allows one to single out the most vulnerable structures. Some examples are presented in this paper, representative of recurrent damage in the main elements of the church: the facade, the roof, the apse and the belfry. It emerges that, for a correct interpretation of damage and vulnerability, it is necessary a deep knowledge of local construction techniques and of the historic transformation sequence. Moreover, the bad behaviour of churches strengthened by modern techniques, such as the substitution of original timber roofs with stiff and heavy r.c. slabs, was observed. Starting from the observation of some case studies, the paper achieves some worth results, which may be useful for correctly driving future strengthening interventions.

163 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a method called Masonry Quality Index method, which consists in evaluating the presence, the partial presence, or the absence of certain parameters that define the "rule of the art", namely a set of construction devices that, if executed during the construction of a wall, provides a good behavior and ensure the compactness and the monolithicity.
Abstract: It is known that the mechanical behavior of masonry material depends on many factors, such as compressive or shear strength of components (mortar and blocks), blocks shape, volumetric ratio between components and wall texture, that is the result of applying a series of construction devices which form the “rule of the art”. Taking into account the complexity of the problem due to the great number of variables, a fair assessment of the load carrying capacity of masonries can be made only with in situ test. Being in situ test a semi-destructive methods, not always viable, a numerical estimate of the mechanical parameters of the walls can be made on the basis of a qualitative criteria evaluation. The method here proposed, called Masonry Quality Index method, consists in evaluating the presence, the partial presence, or the absence of certain parameters that define the “rule of the art”, namely a set of construction devices that, if executed during the construction of a wall, provides a good behavior and ensure the compactness and the monolithicity.

131 citations