The recovery and retrofitting techniques adopted for historical structures and archaeological sites face an apparent dichotomy between conservation of constructions and the safety of users. Literatures show several examples where the current day structural safety of historical constructions, gets defined by the nature of past interventions, the compatibility of materials and elements used in retrofitting. The adopted interventions were, in their time, considered innovative, but over the years their compatibility and reversibility leave the historic constructions structurally vulnerable. For these reasons, a careful understanding of the structural systems is fundamental for the implementation of appropriate retrofitting solutions. Especially for monuments and Archaeological sites the objective to be achieved has to be clear, avoiding destructive investigation tests. In this work the instabilities caused by a consolidation intervention on some travertine columns in a sector of the Flavian Amphitheatre, better known as “Colosseum” in Rome, are critically analysed. The current consolidation operations are compared to the previous one. The restoration activity involves in-depth diagnosis process: the historical analysis of the failures and restorations of that area of the Colosseum, a survey of the crack pattern and an indirect investigation on the travertine of the columns. Subsequently the various data coming from the knowledge phase are elaborated, in order to have a correct interpretation of the causes triggering the failure and guide the choice of the most correct retrofitting techniques.

This article addresses seismic vulnerability assessment at an urban scale using mechanical methods, more specifically potential improvements by involving typological curves instead of standard capacity curves and by using accurate displacement demand determination for reliable building damage prediction. The impact in terms of damage grades is computed for two typical Swiss cities. In Europe, seismic-vulnerability assessment is usually performed using the Risk-UE methodology, which involves an empirical approach (LM1 method) and a mechanical approach (LM2 method). The LM2 method contains standard capacity curves of conventional building types for computation of the corresponding damage grades. These capacity curves have been developed for southern Europe and are not optimal for describing features of other building stocks. New specific refined capacity curves are developed for northern Europe. Eurocode 8 prescribes the computation of displacement-demand for seismic assessment of existing building through a process based on the N2 method. However, the inaccuracy of the N2 method in certain conditions has already been studied. Therefore, modifications of N2 method have been proposed to improve the reliability of displacement-demand determination. In this study, the impact of typological capacity curves and the modified N2 method are investigated independently. Results show that both refinements contribute to improve the damage-grade distribution assessment.

This paper addresses seismic vulnerability assessment at an urban scale by focusing on the displacement demand determination for building damage prediction. The study is based on the comparison of urban seismic damage distributions obtained by the displacement demand computed using non-linear time-history analysis (NLTHA) with three simplified methods. These methods include the N2 method, the Lin & Miranda proposal and an optimized version of the N2 method. Comparing the different damage distributions from the three simplified methods with the one obtained by time-history analysis helps understanding the reliability of displacement demand determination. The study is carried out on Sion and Martigny, two typical Swiss cities. For the case of Sion, results clearly show that using N2 method may lead to significant overestimation of damage grade distribution. The use of Lin & Miranda method and optimized version of N2 improves the damage prediction in both cases. For the other studied case of Martigny, N2 method and Lin & Miranda proposal are not accurate. The optimized version of N2 method provides stable and reliable results.

This paper addresses seismic vulnerability assessment at an urban scale and more specifically the capacity curves involved for building damage prediction. Standard capacity curves are a function of predefined building typology and are proposed in the Risk-UE LM2 method for computation of the corresponding damage grades. However, these capacity curves have been mainly developed for building stock of southern European cities and the accuracy of their application with different building features, such as the ones of cities of northern Europe should be assessed. A recent research project of seismic scenarios for the cities of Sion and Martigny in Switzerland provided the opportunity to check the capacity curves of Risk-UE LM2 method. Within the framework of this project, a detailed analysis was achieved for more than 500 buildings. These buildings were typical Swiss buildings and were composed of both unreinforced masonry buildings with stiff floors and reinforced concrete buildings. The construction drawings of each building were collected in order to have the most accurate information about their main structural characteristics. The typological classification that has been adopted was developed in a recent research project. Based on the individual features of the buildings, individual capacity curves were defined. Results of the seismic assessment applied to the 500 buildings compare very well with those obtained by using Risk-UE LM2 method for unreinforced masonry buildings with stiff floors. A slight improvement may be proposed for buildings with three stories through their introduction to the category of low-rise instead of mid-rise buildings. By contrast, accuracy for reinforced concrete buildings with shear walls is very poor. Damage prediction using related capacity curves of Risk-UE LM2 method does not correspond to reality. Prediction is too pessimistic and moreover damage grades increase with the height category (low-rise, mid-rise and high-rise) of these buildings which is in contradiction with the observed damages for this type of buildings. Improvements are proposed to increase the accuracy of the seismic vulnerability assessment for northern European building stock. For unreinforced masonry buildings, a slight modification of the limits of the height category of buildings using the ones defined for RC buildings improves the damage prediction. For reinforced concrete buildings with shear walls improved capacity curves derived from the typological curves of the specific typology C are proposed.

This paper contains a seismic assessment at urban scale of the cities of Sion and Martigny in Switzerland. These two cities have been identified for the present research based on their importance regarding size and the characteristics of the building stock for which information was available. Moreover, microzonation investigations are available for both cities. This results in a more accurate characterization of local expected ground shaking, which is expressed through specific response spectra. Sion and Martigny represent, respectively, the capital and second largest city of the canton of Valais. This region is characterized by the highest seismicity within Switzerland. The paper focuses on the assessment using Risk-UE methodology, namely the empirical method LM1 and the mechanical method LM2. The obtained results are compared in order to assess the related accuracy. Firstly, buildings of the two cities were surveyed in order to collect main structural characteristics in a database. Building stock is typical of that region and can be found similar to many other medium-sized Swiss cities. Around half of the buildings are unreinforced masonry buildings, while several others are reinforced concrete buildings with shear walls. Results show the most vulnerable part of the cities regarding earthquake. There are significant differences in global results between LM1 and LM2 methods. The mechanical LM2 method is more pessimistic since it predicts damage grades of about one degree higher than LM1 method. However, the main drawback of the empirical LM1 method is that an a priori determination of an adequate value of the macroseismic intensity is required. Nevertheless, LM2 method may lead to a global overestimation of damage prediction.

Introduction and objectives. In Italy Out of Hours Primary Care visits for elderly population are progressively increasing. This findings seems related to the demographic changes that estimate in Liguria an average elderly population of 27.7% (> 65 years) vs an average of 20.3% in the rest of the Italian country. The study is aimed to analyze the type of population using the service, stratifying it on the basis of gender, age and geographical origin. Reason for the visit and related clinical outcome (treatment at home or performance urgent admittance to ER) were also collected to provide a clinical and epidemiological profile of the examined population. Methods. Retrospective observational study. Collecting data from the registers of visits of Out of Hours Primary Care deposited in the archives of ASL4 Chiavarese, Genova, Liguria in the last quarter of 2013. Results. We collected data from 1047 visits in 3 different counties (rural counties of Cicagna and Borzonasca, city county of Rapallo). The average age of the population is 58.63 years (DS 25.29 0.72; range 0-106 years). Fifty one and fifty eight% of overall visits were performed to persons under 65 years of age while 48.43% of visits were performed to subjects 3 over 66 years. Hospitalization rate resulted higher in the older patients (10.37% vs 17.95%). Discussion. The study results showed that Out of Hours Primary Care service deals with geriatric patients in half of cases; elderly subjects have a peculiar clinic phenotype and due to multimorbidity are prone to require urgent services more frequently. The results of the study addressed the need to reframe the health care policy and organizational models in order to fulfill the pressing need of a demographic transition and to figure out innovative health care services where the geriatrician might act as reference professional among a multidisciplinary team involved in the care of elderly patients.

The Swiss authorities have recently put into place a codified procedure for the seismic risk evaluation of public structures. This methodology has been developed by the Office Fédéral des Eaux et de la Géologie (OFEG) and is based on a three-step general procedure for the evaluation of the seismic risk. The first step is a simplified method and has been developed without any calibration through comparison with actual damage observed after seismic events. This leads to a high level of uncertainty regarding the reliability of the method. This body of work aims to rectify this by evaluating the reliability of the Swiss procedure by applying the method to Italian structures damaged by the 2002 Molise earthquake. The method has been examined in its aim to provide priority lists for a limited number of structures and in defining damage scenarios on a territorial scale. The analyses carried out used masonry structures.

The knowledge of existing buildings is an overriding issue for any structural evaluation. The importance of knowledge development is highlighted by the recent Italian Technical Code (M. D. 14 January 2008, M.D. 9 February 2011 4), that introduces different knowledge levels and correlates each level to a confidence factor, depending on the reliability of data, adopted in structural safety checks. Although for cultural heritage interventions (Italian "Guidelines for seismic-risk assessment and mitigation for cultural heritage") a high level of knowledge is desirable (to protect the construction from too preventive interventions), in many cases, for the invasiveness of tests or, simply, for economic reasons, it is not possible to achieve this level of deepening. Therefore it is necessary to define experimental test campaigns, in order to identify which investigations are strictly necessary to achieve a knowledge level appropriate to design retrofit interventions. The goal of this research is to propose an approach that exceeds the rigid schematization defined in the recent technical code for construction, based on the definition of the confidence factors related to the level of knowledge. This aim is achieved through structural pre-analysis from which we can obtain parameters that play a significant role on building safety. This decision-making process is exemplified in the case study of St. Pardo Cathedral in Larino (Italy), damaged by the 2002 Molise earthquake. In the case study, it is demonstrated how a sensitivity analysis of construction details, considered in the structural evaluation, can direct both an experimental test campaign and seismic improvement interventions.

The seismic response of historical un-reinforced masonry (URM) buildings is strongly dependent on the characteristics of wooden floors and in particular on their in-plane stiffness and on the wall-to-diaphragm connections quality. It is generally well-recognized that an adequate in plane-stiffness and proper connections allow to improve the three-dimensional response of the whole system and obtain a better distribution and transfer of forces to the lateral load resisting walls. Extensive damage observed during past earthquakes on URM buildings of different type have however highlighted serious shortcomings of typical retrofit interventions adopted in the past with the intention to stiffen the diaphragm. Recent numerical investigations have also confirmed that stiffening the diaphragm is not necessarily going to lead to an improved response, sometimes actually having detrimental effects. In this contribution, the role of the in-plane stiffness of timber floors on the seismic response of URM buildings, in terms of in-plane, out-of-plane and local corner expulsion mechanisms, is discussed. A performance-based assessment and retrofit strategy, capable of accounting for the effects of flexible diaphragm on the response before and after retrofit intervention, is also proposed and applied to a case study building.

The seismic response of existing un-reinforced masonry (URM) buildings is strongly dependent on the characteristics of wooden floors and in particular on their in- plane stiffness and on the quality of the connections between the floors and the URM elements. It is generally well-recognized that adequate in plane-stiffness and proper connections improves the three-dimensional response of the whole system and provides better distribution and transfer of forces to the lateral load resisting walls. Extensive damage observed during past earthquakes on URM buildings of different type have however highlighted serious shortcomings of typical retrofit interventions adopted in the past with the intention to stiffen the diaphragm. Recent numerical investigations have also confirmed that stiffening the diaphragm is not necessarily going to lead to an improved response, sometimes actually having detrimental effects on the response. The evaluation of the in-plane stiffness of timber floors in their as-built and retrofitted configuration is still an open question and delicate issue, with design guidelines and previous research results providing incomplete, when not controversial, suggestions to the practitioner engineers involved in the assessment and/or retrofit of these types of structures. In this contribution, a summary of the state-of-the-art related to the role of the in-plane stiffness of timber floors in the seismic response of un-reinforced masonry buildings is presented and critical discussed based on the limited available experimental and numerical evidences. A framework for a performance-based assessment and retrofit strategy, capable of accounting for the effects of flexible diaphragm on the response prior and after the retrofit intervention, is then proposed. By controlling the in-plane stiffness of the diaphragm, adopting a specific strengthening (or weakening) intervention, the displacements, accelerations and internal forces demand can be maintained within targeted levels, in order to protect undesired local mechanisms and aim for a more appropriate hierarchy of strength within the whole system.

In order to evaluate the seismic vulnerability of ancient bell towers, the simplified mechanical model proposed into Italian document “Guidelines for evaluation and mitigation of seismic risk to cultural heritage” was applied to a sample of 31 bell towers damaged by the 1976 Friuli (Italy) earthquake. The seismic safety level has been evaluated taking into account the seismic input of the 1976 seismic event, in order to compare the forecast obtained by this simplified model with the observed damage. The comparison has highlighted some limits of the proposed methodology, based on the hypothesis of a tower with cantilever behaviour, constrained at the base that collapsed to axial compression and bending action. Such behaviour is not often confirmed by the damage observation. The crack patterns put in evidence the development of local collapse mechanisms ruled mainly by the equilibrium loss of masonry portion instead of crushing phenomena. The bell towers are not frequently able to develop an overall behaviour for the lack of interlocking corners or of steel tie-rods or of well-connected diaphragms. In the paper the authors proposed a new simplified method to evaluate the seismic risk of towers, based on the analysis of the constructive characteristics of the structure.

The study focused oil the experimental investigations and numerical analyses regarding file staircases in the interior of two historical buildings (named Caffa and Metellino) in the refurbished area of the docks of Genoa harbour (Italy). Those stairways are Made up of stone elements (pink granite of Sardinia Island) and show a particular constructive technique that allows the monolithic steps to be linked together, providing an overall behaviour among steps of a flight and among flights. This technique, Suggested by the prescription (or rule Of thumb) of various ancient building manuals, allows file Stress field to be distributed on each element and it was modelled by means of FEM, in order to verify the effect of this technical measure relative to various load cases. The numerical simulation, carried out through a detailed non-linear solid model of the flights of steps, was preceded by all exhaustive diagnostic campaign (in situ and laboratory tests). useful in order to define. both through direct and indirect tests, the mechanical parameters to be adopted. The obtained results were crucial to preserve the staircases without performing any structural intervention that Would have been useless (if not harmful), modifying the architectonical and historical value of the Original structure of the stairways.

This paper describes the methodology applied to two churches of the Garda area damaged by the 2004 earthquake in order to define the repair intervention. After interpretation of the damage causes, based on an accurate onsite survey and documentary research, the intervention strategies were supported by an onsite testing campaign.

The post-seismic damage assessment of slender structures has highlighted the difficulty to foresee their structural response. The observed damage of this kind of buildings are different although the constructive and typological details are, often, very similar. The belltower analysis is meaningful in Italy for the high number of ancient religious buildings. In order to evaluate the seismic response of this kind of structures, in this paper the bell-towers have been simulated by two sub-structures (tower and belfry). Dynamic analyses have been carried out and the amplification effect at the base of the belfry has been evaluated in spectral quantities. At the same time a statistical analysis of the available data surveyed after the recent Italian seismic events has been carried out, defining, therefore, the vulnerability curves of the two different macroelements (tower and belfry). This approach has allowed us to highlight the fundamental rule of the dynamic characteristics of the structure and of the seismic input, confirming, in a qualitative way, the results obtained by the dynamic numerical analyses. besides supplying useful information about the typological and structural vulnerability of these structures, allowed confirmation, even though qualitatively, of the numeric results. 2 ASSESSMENT OF THE SEISMIC INPUT OF A BELL TOWER From the analysis of the post-earthquake damage to bell towers it came out how often the belfry, despite showing different damage typologies and collapse mechanisms, is an element characterized by high vulnerability within the structure. Part of this vulnerability may be associated with the summit position of this macroelement. Indeed, it is affected by the filtering effect of the structure that can generate, at the height of the belfry impost, substantial variations of content as a frequency of the ground level input. In order to seize on the relevance of this aspect, different dynamic elastic analyses of actual bell towers were carried out, of which are shown, to be brief the results of the bell tower of the church of S. Cassiano in San Casciano dei Bagni (Siena) deemed representative for its shape and dimensions of the typology under scrutiny (Casolo 1996, Casolo 1998, Casolo 2001). The bell tower has a square plan with dimensions of the base section equal to 5.30 m and a total height of about 27.4 m. The modelling of the bell tower was carried out using a simplified schematization, containing beam elements (BEAM4) having six degrees of freedom per node. To this end the bell tower was subdivided into seven sectors with constant geometric and elastic characteristics, in such way as to associate beam-elements having the same characteristics for each sector. The axial and shear elastic modulus (E and G) were assumed as constant throughout the bell tower, respectively equal to 1050 N/mm and 175 N/mm. Figure 1 : reference system adopted for the sectors. Table 1 : Geometric features of each sector Area Height Moment of inertia x axis Moment of inertia y axis Moment of torsional inertia m m m m m Sector 1 18.3 2.2 61.3 50.7 72.2 Sector 2 21.1 5.2 61.6 61.6 83.5 Sector 3 20.3 1.2 61.6 58.3 80.4 Sector 4 19.1 3.2 60.9 53.3 73.7 Sector 5 16.0 6.3 50.5 48.6 66.1 Sector 6 12.3 4.9 39.7 39.7 54.4 Sector 7 8.1 4.4 28.5 28.5 36.23 The presence of ceilings, vaults or concentrated masses (i.e. bells), was modelled by introducing at the level of each floor, some additional masses (MASS21). This model, considered perfectly embedded at the base, allowed assessment, through a modal analysis, of the periods of vibration and the associated modal forms. Table 2 : Vibration periods and modes Mode Period (s) Predominant vibration direction 1 0.9427 x – first mode 2 0.9110 y – first mode 3 0.3824 Torsional 4 0.2306 x – second mode 5 0.2283 y – second mode 6 0.1404 Torsional 1068 Structural Analysis of Historical Constructions E. Curti, S. Lagomarsino and S. Podestà Later a dynamic elastic analysis was carried out, using a matching Eurocode 8 response spectrum (EC8), applied in the direction of the first mode and requiring in output the nodal displacements at the summit height of each sector into which the structure was subdivided. Knowledge of the time-history of displacement and consequently relative acceleration allowed attainment of the temporal histories of the absolute accelerations at the height of each sector, adding them to the input accelerogram. Definition of the elastic response spectrum associated with each accelerogram highlighted the filtering effect of the structure directly in spectral terms. In Fig. 2 the elastic response spectrums obtained in correspondence with each sector are shown, starting from the one placed at the lowest height. It is pointed out how the spectrum at the height of sector 6 is representative of the input that acts at the base of the belfry.

In this paper the Author proposes a damage model for the analysis of masonry plates and shells, which is based on an improvement of a previous constitutive model. The modifications introduced, connected to the head joint damage, allow us to study the influence of masonry texture on the damage modes once the mechanical characteristics of the elements constituting the masonry and the results of tests on simple assemblages are known. Having a nonlinear constitutive model is certainly one of the basic elements for understanding the damage mechanisms in masonry buildings. If, in fact, an elastic-linear constitutive model may be used under normal loading conditions, in critical situations it is necessary to model the damage and the dissipation mechanisms that occur between the elements, stone (brick) and mortar, in correlation with their characteristics and kind of masonry. To validate the model a comparison is made between the numerical and experimental results, in the case of tests available in the literature in masonry panels subjected to out-of plane loading and in a real structure through the observation of the damage in Umbria (Italy) surveyed after the 1997 earthquake.

The need of verifying the integrity, and thus the efficiency, of large diameter pile foundations has lead, in the last years, to the development of non-destructive investigation techniques, based on the theory of waves propagation through elastic media (Timoshenko and Goodier, 1934), in order to detect both the real length and the possible imperfections due to the construction process. In the following paper the Authors outline some suggestions to best interpret the standard ecometric field data, after an extensive site experimentation performed on a 344 pile-group.

This paper describes a new methodology used to assess seismic damage in the churches of Umbria and the Marches, which is based on 18 indicators, each representative of a possible collapse mechanism for a macroelement. The subdivision of the church into macroelements consists of the identification of architectonic elements in which the seismic behavior is almost independent from the rest of the structure (façade, apse, dome, bell tower, etc.). For each macroelement, by considering its typology and connection to the rest of the church, it is possible to identify the damage modes and the collapse mechanisms. During inspection operations, the surveyors must indicate: (a) the actual macroelements; (b) the damage level; and (c) the vulnerability of the church to that mechanism, related to some specific details of construction. From these data a damage score is defined, which is a number from 0 to 1, obtained as a normalized mean of the damage grades in each mechanism. The analysis of the collected data (more than 1,000 churches in Umbria) allows the definition of the correlation between macroseismic intensity and damage.

In the context of a seismic prevention strategy, vulnerability analysis has the aim of acquiring knowledge of the buildings in a region, with particular reference to their predisposition to be damaged by an earthquake. The goal may be both at a territorial level, to assess the damage scenario expected after an earthquake of given intensity, and at a detailed level, as a support to the planning of seismic improvement interventions. The latter objective is very important for ancient churches, due to their architectural and historical value. They definitely need a more profound analysis. The survey with the new form proposed in Part I of this paper allows us to highlight the specific vulnerability with regard to the different collapse mechanisms that are typical of earthquakes, taking into account, if present, the damage due to historical events as an observed vulnerability.

In autumn 2002 two moderate energy earthquakes (31 October, 10:32 GMT, MW = 5.4, and 1 November, 15:08 GMT, MW = 5.0) struck the provinces of Campobasso and Foggia (southern Italy). The earthquakes attained an intensity VII (Modified Mercalli scale) throughout the epicentral area, except for the village of San Giuliano di Puglia, that suffered an intensity VIII-IX. Damage and vulnerability surveys on monuments (churches) suggested that the geomorphological site conditions greatly affected the damage level. In particular we found that, for a comparable intrinsic vulnerability of the building, the structural damage level is directly correlated to local amplification phenomena related to the different morphological and lithological characteristics of each church site. The assessment of damage increase related to local amplification of the ground shaking is made possible by evaluating the damage and seismic vulnerability of each church (e.g., the lack of antiseismic protection, the presence of vulnerability indicators). The damage increase was compared to the morpho-lithological characteristics of each site, schematized with a few simplified parameters. This methodology allowed us to evaluate separately a morphological hazard, related to the topographic characteristics of the site and the building location, and a lithological hazard, evaluated on the basis of the Italian Seismic Code. Our research goal was to set up an expected damage evaluation method, that considers not only the building vulnerability, but also the additional vulnerability related to the morphological conditions of the church site. The methodology can be effectively used in preventive analyses, targeted to define a priority list of historic buildings and monuments at high seismic risk.