ELARCH Project: Prioritization of threats of cultural heritage for the development of a hazard map. The case study of Aragon’s Castle, Venosa (Italy).

In recent years it has highlighted global interest in disaster prevention and risk mitigation, and the importance of cultural heritage and conservation. According to the literature, the risk is directly linked to two variables: vulnerability and threat, the first related to intrinsic causes of the element and the second to external phenomena. This work is aimed to risk analyses of the Castle of the municipality of Venosa, located in the region of Basilicata (Italy). By studying the threats of the area, based also on historical records of the territory, it has been developed a classification of them, categorized in according to their impact level that could be catastrophic, mild or no harm. Development of threats map by using geographic information systems (GIS) is also discussed

Seismic assessment of masonry churches in Matera landscape

Dramatic human and economic consequences are nowadays still resulting from disasters caused by natural phenomena, as in seismic-prone areas, where comprehensive risk management plans for the conservation of cultural property have not been yet completely developed. In particular, earthquakes have destroyed a large amount of cultural heritage in Italy, country which has currently the largest number of World Heritage sites. Matera landscape, located in Southern Italy into a seismic-prone area with moderate seismicity, is characterized by many and important ancient masonry churches, concentrated in The Sassi and the Park of the Rupestrian Churches of Matera, recognized as Cultural World Heritage by UNESCO since 1993. Some masonry churches are evaluated with two simplified procedures for seismic risk assessment, which are based on qualitative and quantitative parameters. Both procedures are complementary and they allow us to define a numeric priority for planning the preventive conservation of the Cultural Property at territorial scale. The qualitative tools aim to identify the main vulnerabilities and hazards for guiding preventive conservation projects, specific studies and risk mitigation. Whereas, the quantitative procedure allows to identify the most vulnerable macro-elements and to plan the retrofitting interventions depending on the assumed reduced nominal life

Seismic vulnerability of old Italian fortifications

The damages recorded in the recent seismic events have highlighted that also very robust structures, such as old castles, are vulnerable with respect to not too high seismic actions. However, the damages have allowed not only of understanding the structural behavior of these ancient old fortifications, but also the influence of many factors affecting the specific response. In this paper an overview of the most recent developments in the seismic assessment of Italian medieval castles is presented. The study discusses on the identification of the most vulnerable elements and on their analytical evaluation. Then, an application to an ancient castle chosen as case study is shown

Fatigue behaviour and residual service life of existing masonry arch bridges

The conservation and safety assessment of old masonry arch bridges represent nowadays a research field of considerable interest. Most of them are testimonies of the past with a significant historical and cultural value, and represent nowadays a large part of the transport infrastructures serving strategic link for roads and railways networks. In many cases their masonry primary elements are already deteriorated due to weather conditions and to the effects of cyclic traffic loads that are increased in both the frequency and the intensity with respect to the past. Even if the ultimate load is not reached, the cumulated damage along with the localised deterioration can reach levels not acceptable leading the entire structure out of service. This paper is addressed to the fatigue assessment of old masonry arch bridges with particular attention to the residual service life evaluation of the arch elements. Unlike of metals and metallic structures, little informations are available to date on the fatigue behaviour of masonry elements, also confirmed by the fact that there are no specific guidelines for assessing the fatigue limit and the residual life. The paper at first shows a critical review of the damage models for the fatigue performance assessment of masonry arch bridges. Then, an application to a case study is presented, where also the influence of intradosal C-FRP reinforcement on the residual service life and the ultimate capacity is discussed

Seismic risk assessment of historic constructions: comparative analysis of masonry and adobe churches in Italy and Chile

This paper proposes to compare seismic risk assessment of historic constructions in Chile and Italy - two seismic prone countries with their own seismological conditions, construction histories and heritage buildings - in order to contribute to the construction of a rapid seismic risk assessment method of heritage buildings in Chile by using innovations and lessons learned in past earthquakes in Italy. To that end, this paper focuses on applying two simplified methods, based on expert judgement and observed damage in old masonry churches, with the aim of identifying the most vulnerable elements and correlated threats that would act as site effects under the seismic action, for establishing intervention priority lists and for planning preventive conservation projects. The case studies are two churches in Matera, Italy; one church in the Andean northern Chile; and two churches in Valparaíso, Chile. Finally, the paper discusses the applicability of these methods for Chilean conservation management plans for cultural propert

An analytical formulation of stress-block parameters for confined concrete

In order to evaluate the capacity of RC members, the main codes allow the use of stress-strain laws that can re- produce closely the real behaviour of concrete, as opposed to parabola-rectangular or equivalent rectangular diagrams. Both sectional strength and ductility depend on the law of concrete, therefore they are influenced by the confinement of members, as evidenced in the literature. In this paper a possible design approach is presented, based on classic section analysis methods. The method uses parameters that represent the stress-strain law of confined concrete. The studies car- ried out show that such parameters can be chosen through simple relationships depending on the strength of non-confined concrete, on the amount and geometry of longitudinal and transverse reinforcement, and on the geometry of the section. At this aim some numerical analyses have been performed using an analytical model of confined concrete, capable of tak- ing into account all the mentioned effects, even in the case of various sources of confinement, when different types of hoops and external elements (FRP wrappings, steel plates, etc.) are used. More in detail, the section interaction diagrams for the different limit states requires the definition of an appropriate upper bound for the strain of concrete. Therefore the study focuses on the possibility of using stress-blocks depending on the maximum stain assumed, or on the level of resid- ual stress accepted in concrete according to a specified limit state. Further studies will extend the parametric analysis in order to obtain design equations to be implemented in codes

Estimation of churches frequencies based on simplified geometry parameters

Nowadays, the modal properties of structures can be obtained by experimental methods that are still expensive for professionals who have to deal with the seismic assessment. Additionally, for heritage buildings, due to their complexity, the identification of the modal properties can be challenging and requires of experience on the field. This paper aims to develop a methodology to predict the frequency response of churches based on simplified geometrical parameters. In this context, an extensive literature review was carried out to collect data, aiming to define the principal typologies of churches. Afterwards, a parametric analysis with numerical simulations of the eigenvalue problem was performed to identify which are the main geometrical parameters that influence the dynamic behavior of the churches. The correlations between the natural frequencies and relevant geometrical parameters are illustrated and discussed in order to develop a proposal for the estimation of the natural frequencies of the churches. Churches with single nave and three naves were defined as the two principal types of churches, and six equations were proposed, aiming to estimate the first three natural frequencies for each type of church. Finally, the methodology was validated on real case studies found in literature, in which experimental identification of frequencies was performed. This comparison allowed to evaluate the accuracy of the method to estimate the natural frequencies.- (undefined

NONLINEAR SEISMIC ANALYSIS OF GRAVITY-DESIGNED RC STRUCTURES

This paper illustrates numerical simulations and comparisons with experimental results of existing RC beam-column sub-assemblages reinforced with smooth bars. The specimens reproduce parts of concrete structures designed only for vertical loads without any reinforcing detail rule (such as inadequate bars lap splice, absence of hoops within the joint panel) built in Italy during ‘50s-‘70s. In particular, in this paper is paid attention to the nonlinear models developed for predicting the failure mechanism experimentally observed, taking also into account the bond-slip phenomenon among the longitudinal bars and surrounding concrete. The proposed models are not time-consuming and may be easily implemented in any general-purpose finite element program for numerical simulations of concrete structures. These models represent an useful tool for seismic assessment with a good accuracy of nonductile RC existing structures

Critical regions of RC primary elements detailed in according to provisions rules for curvature ductility: comparisons and numerical analyses

In moment resisting frames beams and columns are designed for flexural, axial, and shear actions due to vertical and horizontal loads. Special proportioning and detailing requirements are applied in these elements for making them capable of resisting against severe earthquakes without significant loss of strength beyond the flexural elastic limit, and avoiding brittle failure (shear mechanisms). As known, the required flexural inelastic excursions (expressed by the local ductility demand) depend on the dissipative capacity of the structure. The flexural ductility significantly increases with the transverse reinforcement amount provided to confine section core and to prevent buckling of compressed longitudinal bars. In this paper detailing provisions adopted by some seismic codes are compared. At first, the codes provisions to be applied within critical regions of RC primary frames sections are discussed and compared as a function of the curvature ductility demand. Then, non-linear monotonic moment-curvature analyses are performed on fiber sections of columns and beams, and by taking into account the confinement effects on concrete core as well. The numerical investigations are carried out for comparing the available curvature ductility with the expected one applying the provisions mentioned by the seismic codes

Comparisons of Codal Detailing Rules for Curvature Ductility and Numerical Investigations

In moment resisting frame structures special detailing rules are applied to critical regions of primary columns and beams to ensure adequate curvature ductility. This is necessary for dissipating earthquake energy through hysteretical behavior of critical regions where inelastic flexural excursions occur. In this paper codal detailing rules for designing longitudinal and transverse reinforcement of primary elements as function of curvature ductility are assessed. Four seismic codes are considered: Italian code, New Zealand code, Eurocode 8 and American code. Non-linear monotonic moment-curvature analyses are performed on some sections of columns and beams detailed in according to the considered codal provisions. In the analyses the confinement effects within the concrete core have been taken into account as well. The paper concludes comparing the measured curvature ductility of the studied sections with the expected one by the codal pro- visions within the critical regions