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The earthquake of the 9th of July 1998 that hit in the central group of the Azores archipelago greatly affected the islands
of Faial, Pico and São Jorge, reaching a magnitude of Mw 6.2 with the epicentre located about 15km northeast of the Faial
Island. This earthquake allowed the collection of an unprecedented quantity of data concerning the chara...
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Context 1
... most common type of floor structure is constituted of timber planks and timber beams. The timber beams are spaced at 0.40 m and are supported over the stone masonry walls (see schematic in Fig. 3) spanning from 3.5 to 4.0 m. This wall plate allows a better distribution of the dead and live loads along the wall length, also allowing a better in-plane structural stiffness and strength distribution. The timber flooring is constituted of timber planks with a thickness varying between 2.2 and 2.5 cm, nailed to the timber framework. ...
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Shake table tests were conducted on five 1:3 reduced scale two story reinforced concrete (RC) moment resisting frames having construction and design deficiencies (built in low strength concrete, lacking confining ties in beam-column joint panels, practicing larger tie spacing and reduced longitudinal & transverse reinforcements). The deficient fram...
Citations
... In recent years, various seismic vulnerability index methods have been developed and applied in historic centres around the world, mainly in Italy (Chieffo et al. 2022;Formisano et al. 2015;Giovinazzi and Lagomarsino 2004) and Portugal (Ferreira et al. 2013;Ferreira et al. 2017b;Neves et al. 2012;Vicente et al. 2011). These are generally based on the index method GNDT II (Benedetti and Petrini 1984) and are qualified as hybrid methods (Ferreira et al. 2019). ...
A comprehensive understanding of the elements at risk, through the identification of the main hazards, level of exposure and different dimensions of the vulnerability of the communities, is an essential step towards the definition and adoption of more effective risk reduction strategies. Historic urban centres have received special attention in the assessment of damage and physical vulnerability to earthquakes, but it is well known that vulnerability also depends on the social and demographic characteristics of communities. This paper discusses the application of a holistic approach aimed at assessing the seismic vulnerability of historic urban centres by considering their physical and social dimensions. Two index-based methodologies are presented, and the data are analysed using the CENSUS block as the unit of study, which is scarcely present in the literature. The results of both indices are crossed through a matrix, which allows the classification of the blocks in five levels of priority and are mapped using a Geographic Information System (GIS) tool. The Historic city centre of La Serena, one of the oldest in Chile, was selected as a case study. This historic city centre still preserves historic buildings of raw earth of diverse architectural typologies widely distributed throughout the country, which makes it relevant, not only by itself but as a model that can be replicated and extrapolated to other historic centres of similar constructive characteristics.
... Various methodologies have been proposed in the literature to assess the seismic vulnerability of URM historic city centers (Barbat et al. 2010;Ferreira, Maio, and Vicente 2017;Formisano 2017;Maio et al. 2015;Neves et al. 2012;Salazar, Gerardo, and Ferreira 2020;Vicente 2008). Despite the volume of research, particularly in countries such as Italy, Portugal, Peru, and New Zealand, the cultural differences between these countries added to the Chilean context in terms of seismic conditions, construction techniques, implemented materials, and architectural and structural typologies, do not warrant a simple extrapolation of the results. ...
... Indirect approaches involving Vulnerability Indices (VIs) overcome some of these limitations (Benedetti, Benzoni, and Parisi 1988). A VI is calculated as a weighted sum of few qualitative and quantitative vulnerability parameters of empirical nature (Neves et al. 2012; Gruppo Nazionale per la Difesa dai Terremoti- GNDT-SSN 1994Grünthal 1998;Sabetta et al., 1998;Lagomarsino and Giovanazzi, 2006;Ozdemir et al., 2005;Palazzi et al. 2020), associated with construction and structural features of the buildings. The vulnerability indices are then used to estimate damage distribution by proper probability functions (known as vulnerability functions), which express in a continuous format the probability of the k-th element to reach a given damage level D k > j, conditioned to a ground motion intensity IM, i.e. ...
... In the second phase, according to Vicente et al. (2008) and assuming that CD and CL&Va classes of Yungay buildings present homogenous features within each typology, the vulnerability of the remaining 216 URM structures was evaluated using a less detailed approach. The mean values of the I v indices for the CD and CL&Va typologies, obtained from the first detailed assessment, were used as a typological vulnerability index modified through the "vulnerability parameters," ΔI v , corresponding to the potential seismic fragilities of aggregate URM buildings usually identified in the literature (Benedetti and Petrini 1984;Brando, De Matteis, and Spacone 2017;Ferreira, Maio, and Vicente 2017;Ferreira et al. 2013;Lagomarsino and Podestà 2005;Maio et al. 2016;Neves et al. 2012;Rapone et al. 2018). ...
In this paper, a modified empirical large-territorial-scale procedure to assess the seismic vulnerability of aggregate buildings in urban areas located within a highly seismic context is proposed. The methodology is applied to a group of unreinforced masonry (URM) aggregates located in the Yungay’s historic center in downtown Santiago, Chile. This assessment was carried out by modifying and integrating a vulnerability-index-based procedure, a specific existing approach called first level macro-seismic method used to predict seismic damage and loss scenarios through fragility curves of structural components. The procedure was calibrated using the observed damage after the 2010 Chile earthquake in 292 URM structural units. The results of this new damage index for URM aggregate buildings are used to derive Probability Mass Functions (PMFs) of the different damage states and preliminary Empirical Fragility Functions (EFFs). To the best of the authors’ knowledge, these EFFs are the first publicly available for aggregate Chilean URM buildings. This research and its results are the starting point for a more comprehensive study for assessing damage scenarios and vulnerabilities of aggregate URM buildings in historic centers of older Chilean cities. These functions may be used in risk assessment, and are useful to prioritize possible future damage mitigation strategies and other processes involving this historical heritage. We foresee that these results could be at least partially applied to other historical urban areas in Chile, and perhaps other old Latin American cities located along the subduction convergence region between the Pacific and Continental plates, which were founded similarly.
... Many people in seismic-prone areas live in old historic centers made of low-rise buildings (mostly 2/3 stories) characterized by masonries with poor quality mortar [1,2]. Enhancing the seismic response of these buildings is of paramount importance, both for public safety and for increasing the tourist attractivity of the historic centers that these buildings populate. ...
This paper deals with the results of an experimental and numerical campaign aimed at characterizing the mechanical response of masonry components and panels made of limestone units kept together by weak air lime mortar joints. The selected air lime mortar, typical of ancient masonry buildings but difficult to be built-up artificially, was specifically prepared for the experimental analyses, with the aim of obtaining a laboratory compression strength of 0.25–0.50 MPa. In the first part of the paper, the performed tests concerning the strength of the units (mean compression strength of 80 MPa) and of the mortar (mean compression strength after 28 days of 0.30 MPa), are described for different curing periods. Moreover, tests of masonry triplets in shear (shear strength of 0.11 MPa for null axial forces) are shown and used in order to establish the main parameters of the Mohr–Coulomb failure criterium. Then, the calibration of a continuous numerical micro-model implemented in Kratos Multiphysics is presented. The model is used for reproducing the behavior of an unreinforced panel in shear made of the studied masonry and to appraise the effectiveness of a FRCM- (Fiber Reinforced Cementitious Matrix) based reinforcement intervention applied. The obtained results proved that FRCM allows to increase the strength of the considered masonry type by about eight times and the ductility by about thirteen times.
... Recent decades have encountered an increasing number of seismic vulnerability assessment models put forth by different researchers based on GIS-based models (Neysani 2009;Neysani Samany et al. 2014;Nadizadeh Shorabeh et al. 2020;Boloorani et al. 2021;Omidipoor et al. 2021;Jelokhani-Niaraki et al. 2020;Naghdizadegan Jahromi et al. 2021;Boloorani et al. 2021;Qureshi et al. 2021;Neisany Samany et al. 2021). Neves et al. (2012) developed a GIS-based model to measure the seismic vulnerability of urban buildings. They considered building damage and population vulnerability factors and integrated them via a spatial model (Karimzadeh et al. 2014). ...
Seismic vulnerability assessment of urban buildings is among the most crucial procedures to post-disaster response and recovery of infrastructure systems. The present study proceeds to estimate the seismic vulnerability of urban buildings and proposes a new framework training on the two objectives. First, a comprehensive interpretation of the effective parameters of this phenomenon including physical and human factors is done. Second, the Rough Set theory is used to reduce the integration uncertainties, as there are numerous quantitative and qualitative data. Both objectives were conducted on seven distinct earthquake scenarios with different intensities based on distance from the fault line and the epicenter. The proposed method was implemented by measuring seismic vulnerability for the seven specified seismic scenarios. The final results indicated that among the entire studied buildings, 71.5% were highly vulnerable as concerning the highest earthquake scenario (intensity=7MM and acceleration calculated based on the epicenter), while in the lowest earthquake scenario (intensity=5MM), the percentage of vulnerable buildings decreased to approximately 57%. Also, the findings proved that the distance from the fault line rather than the earthquake center (epicenter) has a significant effect on the seismic vulnerability of urban buildings. The model was evaluated by comparing the results with the weighted linear combination (WLC) method. The accuracy of the proposed model was substantiated according to evaluation reports. Vulnerability assessment based on the distance from the epicenter and its comparison with the distance from the fault shows significant reliable results.
... in the last 25 years in different countries with emphasis on some European countries as Italy, Spain, Greece, among many others (see for instance Vacareanu et al. 2004;Faccioli et al. 2004, Giovinazzi 2005Lagomarsino and Giovinazzi 2006;Barbat et al. 2006;Dolce et al. 2006;Bernardini 2007a, b;Barbat et al. 2009;Vicente et al. 2011;Neves et al. 2012;Ferreira et al., 2013;2017a,b;Athmani et al. 2015; Guardiola−Víllora and Basset−Salom 2015; 2020; Ruiz et al. 2015;Cherif et al. 2016;Lestuzzi et al. 2016;Maio et al. 2016;Apostol et al. 2019;Giuliani et al. 2019;Ortega et al. 2019;Ademović et al. 2020; Basset−Salom and Guardiola−Víllora 2020; Kassem et al. 2020;Romis et al. 2020;Taibi et al. 2020). Recently, Aguilar−Meléndez et al. (2019a) highlighted that the seismic risk results obtained according to the VIM_P agree with the results determined through the application of the VIM. ...
There are personal and institutional decisions that can increase the seismic resilience of the buildings in a city. However, some of these decisions are possible if we have basic knowledge of buildings’ seismic risk. The present document describes the main results of a detailed study of seismic vulnerability and seismic risk of residential buildings of Ciutat Vella (the ancient district of Barcelona) and Nou Barris (one of the newest districts of Barcelona). In this study, we assessed seismic risk according to the Vulnerability Index Method-Probabilistic named as VIM_P. Moreover, we analyzed the influence of basic buildings’ features in the final vulnerability and seismic risk values. For instance, we assessed the seismic vulnerability and the seismic risk of groups of buildings defined according to the number of stories of the buildings. Findings of this research reveal that the annual frequency of exceedance of the collapse damage state in Ciutat Vella buildings is, on average, 4.7 times higher than for the buildings in Nou Barris. Moreover, according to the Best vulnerability curve, 70.31% and 2.81% of Ciutat Vella and Nou Barris buildings, respectively, have an annual frequency of exceedance of the collapse damage state greater than 1 × 10–5.
... Vicente et al. 2011;Chaulagain et al. 2015;Eleftheriadou et al. 2014;Jalayer and Ebrahimian 2017;D'Amato et al. 2018;Novelli and D'Ayala 2019;Quagliarini et al. 2019, etc.), also accounting for real losses related to exposure. Therefore, seismic risk management increasingly gained a fundamental role in urban planning, being relevant for the determination of the most vulnerable buildings within the analysed area and allowing to organise mitigation/retrofit measures according to a cost-benefit overview (Ferreira et al. 2017;Neves et al. 2012). The seismic risk assessment can be considered as a tool to manage the conservation planning for monumental historical constructions, characterised by high complexity, relevance from an architectural, historical and maintenance point of view and therefore needing specific attention during the evaluation process. ...
The present paper deals with the elaboration of a methodology to assess the macro-seismic risk of monumental historical buildings, representing a fundamental part of the European cultural assets. Monumental buildings typically arise from a very complex constructive and morphological evolution process characterised by modifications occurred over the centuries. Therefore, they are usually heterogeneous buildings similar to 'structural aggregates' rather than single constructions and characterised by a structural behaviour depending on the mutual interaction of different structural units. An accurate knowledge process can allow the determination of structural units within the complex: such units can be therefore analysed using a specific evaluation form conceived to provide a 'risk ranking' of the different portions constituting the aggregate and accounting for vulnerability, exposure and seismic hazard parameters. The proposed methodology exploits what is already used to quickly determine structural features and eventual damages in the post-earthquake phase for ordinary buildings, introducing specific aspects typical of historical-cultural heritage requiring attention. According to the results achieved, retrofit interventions or deepen investigations can be planned for units provided by a higher position in the risk scale, optimising and rationally planning the use of available economic and time resources. In the present work, the proposed methodology is applied to the monumental complex of the Certosa di Calci, Pisa (Italy).
... Successively, many studies have been carried out by applying the Vulnerability Index method in aggregate masonry contexts (Athmani, Ferreira, and Vicente 2018;Athmani et al. 2015;Ferreira et al. 2013;Formisano, Chieffo, and Mosoarca 2017;Maio et al. 2016;Neves et al. 2012). ...
... The definition and assignment of weights related to the different parameters represent the most significant source of uncertainty within the Vulnerability Index method (Vicente et al. 2011). The weights take into account the different importance that the various parameters assume for the seismic behaviour of a structure (Benedetti and Petrini 1984) and many authors (Athmani, Ferreira, and Vicente 2018;Athmani et al. 2015;Ferreira et al. 2013;Formisano, Chieffo, and Mosoarca 2017;Maio et al. 2016;Neves et al. 2012;Vicente 2008) considers different weights in their assessments. In this sense, the Vulnerability Index method is based on arbitrary choices (through expert judgment) showing the source of uncertainty, but at the same time highlighting the ability to analyse and evaluate each specific construction culture. ...
Historic urban centers characterised by traditional masonry aggregate patio houses have been studied under many aspects: the patio construction type allows to obtain thermal conditions suitable for particular climatic conditions and introverted interior spaces suitable for specific cultures. Conversely, the seismic vulnerability assessment is not yet thoroughly investigated. This paper proposes a methodology for the seismic vulnerability assessment at the urban scale for traditional masonry aggregate patio houses, developing on Vulnerability Index approach combined with the macroseismic method through vulnerability functions. In particular, an appropriate survey form is proposed by a thorough calibration on the remarkable case study of the Fes medina, UNESCO World Heritage site, which has suffered severe damages from earthquakes occurred in ancient time. The study allowed to realise vulnerability and fragility curves, damage scenarios, and loss scenarios. The method was applied a second time to the case study after simulated structural retrofitting interventions. The vulnerability assessment results are also presented through maps with the Geographic Information System (GIS).
... This is accomplished by using wedges (timber pegs) to secure the wall plate around the circumference of the house through the joists that extend both within and outside the structure. The wall plate, which is a kind of ring-beam that runs along the circumference of the wall, allows for a smoother distribution of dead and live loads along the length of the wall, as well as better in-plane stiffness and stress distribution [10]. ...
Nepal lies in the central part of the Himalayan Range, one of the most seismically active zones in the world. Nepal has a long history of devastating earthquakes. This is due to the subduction of the Indian plate underneath the Eurasian plate. Furthermore, different past researches have mentioned that the accumulated slip deficit is likely to produce large earthquakes in the future. Most of the Nepalese traditional temples, listed in UNESCO World heritage, were built during the period of the Malla dynasty (1200 A.D.-1768 A.D.) Changu Narayan temple, which is considered for the study, is the oldest temple of Nepal built in the 4th century and reconstructed in 1702 A.D. These temples were erected following simple guidelines and design details to satisfy the seismic resistance criteria, or also without any regard for seismic resistance. Studies of the previous earthquakes indicate the potential damage that can occur in unreinforced traditional masonry structures in future earthquakes. The conservation and restoration of these ancient temples are one of the major concerns for the protection of our built heritage and its transfer to future generations. The present paper outlines structural fragility characteristics in the Changu Narayan temple which affects their seismic performance. Every structural problem is aimed to be solved by numerical analysis and calibrated by testing. However, only a little research has been done for experimental testing of structural components of traditional temples. Also, experimental testing for seismic performance of traditional temples is rarely done. Furthermore, the lack of geometric dimensions, material properties, and characteristics of inner construction components makes numerical modeling complicated demanding experimental results or some other ways to calibrate the results. To do so, photographic evidence of the damages in the temple due to the Gorkha earthquake, 2015, and the damage study of the Changu Narayan temple will be used to justify the model analysis. Damages in the fragile member of the temple cause a change in the global stiffness hence changing the fundamental frequency of the temple. To study this, parametric analysis using Finite Element modeling is carried out to identify structural fragilities of the temple, the associated traditional building technology, and constructional details. The findings of this study show that the base storey masonry wall is fundamental in the reduction of global stiffness of the structure followed by wall corners. Timber and roof structures not showing an appreciable reduction in global stiffness indicated that it should be modeled and analyzed separately to understand its structural vulnerability.
... The main requirement of all aseismic codes is the preservation of human lives and the limitation of damage. On this basis, systematically, in Greece and many places around the world (Figures 12-15) [8,11,12,13,14,15], the timber-framed partition walls, is probably the most 'active' non-load bearing element when a severe earthquake strikes, supporting the floors and the roof, preventing fatal collapses of masonry buildings. As written in a precious edition of a book, in which the writer (A.D. Demponiou) [8], describes his memories during and after the earthquake that destroyed Argostoli and many other places in Cephalonia in Greece, '…the internal rooms of the buildings were in good condition, since the roof did not collapse, because it set on the morofinta (μοροφίντα-timber partition walls), that though deformed from the loads, stayed in place'. ...
... (Korkmaz et. al, 2010) [12], in Padang in Indonesia (Bothara et al., 2010) [13], and in Faial Island, in Azores (Neves et al, 2012) [11]. In all the above cases the internal partition walls, prevented the total collapse of the building, supporting the floors after the out of plain failure of the external walls. ...
Keywords: timber-framed structures, non-load bearing timber-framed walls, anti-seismic behavior of timber-framed walls. Abstract The present paper aims at describing briefly the construction typologies of the load-bearing and non-load-bearing timber-framed structures in Greece, focusing on their earthquake performance mainly of the last ones, as parts of an overall structural system, the building. Timber-framed structures constitute usually mixed (composite) structural systems, based in many cases on the collaboration of wood, stone, brick and raw earth. The cases that will be presented are the ones that the timber skeleton is the main load bearing element, as the 2-dimensional timber framed walls with different types of infill or with just plaster. Concerning the earthquake behavior of the non-load bearing timber framed structures, historical research (photographs, documents etc.) and post-disaster observations on-site after strong seismic events, have revealed the valuable structural role of these non-structural elements, which become active during and immediately after the earthquake, preventing in several cases total collapses, saving partially the buildings and the lives of the occupants.
... So, it could be that a method that works adequately in a certain territory, is not adequate in another. In order to collect data finalized to the application of Vis methods, the use of predefined forms filled in by expert technicians, during in situ investigations, was widely adopted in Italy, as well as in other European [25] and non-European countries ( [26,27]). ...
... indicates maximum influence. The ρ I coefficients have been defined according to engineering judgments concerning the observed damage after several seismic events of the past, also by other authors [23,25]. For example, it is widely recognized that the damage is strongly conditioned by the position that the building has within the aggregate; ...
In this paper, a novel predictive model for the seismic vulnerability assessment of old Italian minor historical centres is presented. The proposed methodology is based on the use of eight seismic parameters, which can be easily extracted from the CARTIS form, a new tool for collecting building inventories at the regional scale, promoted by the Italian Civil Protection.
The proposed method takes inspiration from a 14 parameters-based empirical method calibrated by the authors after the 2009 L'Aquila earthquake and validated also on the base of the damage scenarios of the 2016 Central Italy earthquake. However, with respect to the original method, the applied procedure is properly modified in order to provide the same results even if the type amd the number of input information is different.
In the first part of the paper, the CARTIS form is presented. Then the proposed methodology is shown and the eight seismic parameters used for its application are discussed. Finally, in order to show the feasibility of the method, it is applied to the case study of Grottazzolina, a small town located in the administrative region of Marche, in Italy, for which fragility curves are provided as a useful tool for predicting the damage scenarios that could potentially occur under different earthquake intensities. The obtained results represent a useful information to address decision-makers’ actions for the seismic risk mitigation of the studied urban centre.
