86,729 research outputs found
Fragility curves and seismic demand hazard analysis of rocking walls restrained with elasto-plastic ties
No full textThe dynamic stability of out-of-plane masonry walls can be assessed through non-linear dynamic analysis (rocking analysis), accounting for transverse walls, horizontal diaphragms and tie-rods. Steel tie-rods are widely spread in historical constructions to prevent dangerous overturning mechanisms and can be simulated by proper elasto-plastic models. Conventionally, design guidelines suggest intensity-based assessment methods, where the seismic demand distribution directly depends upon the selected intensity measure level. Fragility analysis could also be employed as a more advanced procedure able to assess the seismic vulnerability in a probabilistic manner. The boundedness of this approach is herein overcome by applying a robust stochastic seismic performance assessment to obtain seismic demand hazard curves. A sensitivity study is carried out to account for the influence of wall geometry, the minimum number of seismic inputs, and the mechanical parameters of tie-rods. Fragility analysis, prior to seismic demand hazard analysis is applied on over 6000 analyses, revealing that intensity measures are poorly correlated both for 1-D and 2-D correlation, hardly leading to the selection of the optimal intensity measure. The tie-rod ductility, followed by its axial strength and wall size, is the mechanical parameter mostly influencing the results, whereas the wall slenderness does not play a significant role in the probabilistic response
Handover checklist: testing a standardization process in an Italian hospital
No full textDavide Ferorelli,1 Teresa Giandola,2 Mariangela Laterza,2 Biagio Solarino,2 Angela Pezzolla,3 Fiorenza Zotti,2 Alessandro Dell’Erba1 1Interdisciplinary Department of Medicine, 2Section of Legal Medicine, 3Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy Objectives: This study aimed to standardize and rationalize the handover, a critical and essential moment in common health care practices, through the realization of an efficient and standardized checklist, which could be used daily to ensure complete, thorough and effective handover. The principal purpose of the implementation of the handover is to reduce errors due to superficial and insufficient communication.Methods: The “operative group” defined the phases to the realization of the delineated aims: at first, the direct observation and the consequent realization of a handover checklist model and then, the experimental phases (trials). The handover checklist model was used for a month and it was daily and duly completed by the doctors who took part in the trial. To prove the success of the study, three questionnaires were distributed on different occasions.Results: Analyzing the answers to the questionnaires, the importance of the handover has come to light and that for the most part, the doctors consider it an essential and irreplaceable moment in daily health care work. Moreover, it became obvious that the use of the handover checklist guaranteed a considerable improvement in the traditional handover in terms of security, completeness, care continuity and clarity. The handover checklist was completely appreciated by the majority of the participant doctors who agree with the definitive introduction of it in their unit.Conclusions: Our study indicated the consistency of the handover checklist as an instrument to implement the handover and, indirectly, to improve the quality of the care. Keywords: clinical risk management, handover checklist, health care workers trainin
EDURISK e l'Europa
No full textLa produzione editoriale di EDURISK si è sempre distinta per varietà e completezza, ma soprattutto
per l’estrema cura di tutti gli aspetti scientifici, sociali, comportamentali ed etici trattati.
Durante la vita del progetto sono stati redatti volumi per studenti di ogni fascia di età e grado di
istruzione, e per insegnanti. È grazie alla competenza di diversi autori/studiosi coinvolti che è stato possibile
assicurare la precisione scientifica, la corretta impostazione pedagogica, la più efficace espressione grafica e
assicurare così la più ampia comprensione da parte dei piccoli, grandi lettori.
Il linguaggio tecnico di difficoltà crescente in funzione dell’età dei ragazzi, l’utilizzo di molte figure
ed illustrazioni e la semplicità e chiarezza dei testi sono sicuramente gli elementi peculiari di questi strumenti
formativi. I volumi più significativi sono stati tradotti in diverse lingue europee con l’intento sia di
predisporre alcuni strumenti multidisciplinari che potessero venire utilizzati da insegnanti e studenti di lingue
straniere, sia di raggiungere minoranze linguistiche, studenti di regioni a statuto speciale e ambienti scolastici
in ambito extranazionale.Published57-615.9. Formazione e informazioneN/A or not JCRope
EDURISK e l'Europa
No full textLa produzione editoriale di EDURISK si è sempre distinta per varietà e completezza, ma soprattutto
per l’estrema cura di tutti gli aspetti scientifici, sociali, comportamentali ed etici trattati.
Durante la vita del progetto sono stati redatti volumi per studenti di ogni fascia di età e grado di
istruzione, e per insegnanti. È grazie alla competenza di diversi autori/studiosi coinvolti che è stato possibile
assicurare la precisione scientifica, la corretta impostazione pedagogica, la più efficace espressione grafica e
assicurare così la più ampia comprensione da parte dei piccoli, grandi lettori.
Il linguaggio tecnico di difficoltà crescente in funzione dell’età dei ragazzi, l’utilizzo di molte figure
ed illustrazioni e la semplicità e chiarezza dei testi sono sicuramente gli elementi peculiari di questi strumenti
formativi. I volumi più significativi sono stati tradotti in diverse lingue europee con l’intento sia di
predisporre alcuni strumenti multidisciplinari che potessero venire utilizzati da insegnanti e studenti di lingue
straniere, sia di raggiungere minoranze linguistiche, studenti di regioni a statuto speciale e ambienti scolastici
in ambito extranazionale.Published57-615.9. Formazione e informazioneN/A or not JCRope
A review on wall-to-timber floor anchorages in URM buildings
No full textOut of plane failure of unreinforced masonry walls is considered one of the most vulnerable seismic hazards in medium and high earthquake-prone regions. Efficient structural connections enable global equilibrated mechanisms, ensuring the “box-behavior”. Timber floors are widely used as horizontal diaphragm in historical constructions, and their connection to the boundary walls is crucial to facilitate internal force redistribution and to restrain out of plane walls. Wall-to-floor anchorages are typical in existing historical buildings, and innovative solutions are proposed nowadays by engineers as strengthening devices. Unfortunately, they are often too invasive or unsustainable solutions, applied without reliable seismic design and evaluation through valid models. This paper presents a literature review on the traditional and innovative wall-to-timber floor anchors used in unreinforced masonry buildings taking into account experimental works, analytical and numerical studies
Wall-to-horizontal diaphragm connections in historical buildings: A state-of-the-art review
No full textWall-to-horizontal diaphragm connections play a crucial role in the global stability of historical buildings under seismic actions. When these links are ineffective or absent, engineered measures should be considered to enhance the earthquake-resistant box-type behavior. Besides the great variety on the construction systems and materials, common damages were observed in recent seismic events showing the high vulnerability of local mechanisms promoted by the lack of structural integrity. Although the acknowledged importance of connections, this topic has been practically neglected over time among the research community and practitioners and only few of them focused on the influence of diaphragm-to-wall connections on the dynamic behavior of the building as a whole.
This paper presents a literature review of the traditional wall-to-floor or wall-to-roof connections in unreinforced masonry buildings and summarizes typical and innovative strengthening solutions, taking into account the indications provided by the few design codes addressing this topic. Experimental laboratory researches are investigated, including shaking table tests on global and local scale, and cyclic or monotonic tests to characterize anchoring systems. An overview of the typical vulnerability assessment approaches and modelling techniques is given, considering present standards that account for connections
Are seismogram recorded in schoola educational tools only ?
No full textIn the frame of the NERA project and under the WP 8, an inventory of schools hosting seismic stations for educational purposes has been compiled with the aim, among others, to establish a network for data exchange. Such an inventory reveals that there are more than 600 instruments, most of which in full activity, in schools of the Mediterranean area. The number of stations is somewhat proportional to the date when educational projects began (Zollo et al., in press), so countries like France, United Kingdom or Ireland, all places where a long tradition in “seismology in schools” is established , own most of the existing stations.
The make and technical characteristics of these devices widely vary: some schools have assembled their own mechanical seismometer with very simple materials while some others have designed an acquisition system and coupled it to a sensor available on the market. In some cases, stations are bought from semi-professional or professional manufacturers that have devoted a special care to the educational field. These factories have designed cheap instruments the technology of which is based on the more expensive instruments that are instead available at professional level. These recording items are often equipped with an internet connection, have a broad-band like seismometer, offer a real time view of the recording (helicorder) and provide data in SAC format. In a sentence, they are very much similar to the devices currently used in professional (national or regional) networks to monitor seismicity. Moreover, in principle stations installed in a country are very much alike or perfectly identical, representing as a matter of fact a semi-professional seismic network..
It is then straightforward to wonder what is the role of the data recorded and stored by these instruments and especially what is the potential of these information. Are these instruments providing any additional information to the professional seismic networks ? Could they complement a professional database ?
In this paper a rough analysis of the data collected by a school network is analysed and compared with “official” data. It is shown that in some cases seismograms recorded from stations in schools can perform very well and their data could, under certain circumstances and with some limitations, be used instead of / in addition to professional data.PublishedTeatro Comunale F. Stabile, Potenza, Italy1.1. TTC - Monitoraggio sismico del territorio nazionaleope
Are seismogram recorded in schoola educational tools only ?
No full textIn the frame of the NERA project and under the WP 8, an inventory of schools hosting seismic stations for educational purposes has been compiled with the aim, among others, to establish a network for data exchange. Such an inventory reveals that there are more than 600 instruments, most of which in full activity, in schools of the Mediterranean area. The number of stations is somewhat proportional to the date when educational projects began (Zollo et al., in press), so countries like France, United Kingdom or Ireland, all places where a long tradition in “seismology in schools” is established , own most of the existing stations.
The make and technical characteristics of these devices widely vary: some schools have assembled their own mechanical seismometer with very simple materials while some others have designed an acquisition system and coupled it to a sensor available on the market. In some cases, stations are bought from semi-professional or professional manufacturers that have devoted a special care to the educational field. These factories have designed cheap instruments the technology of which is based on the more expensive instruments that are instead available at professional level. These recording items are often equipped with an internet connection, have a broad-band like seismometer, offer a real time view of the recording (helicorder) and provide data in SAC format. In a sentence, they are very much similar to the devices currently used in professional (national or regional) networks to monitor seismicity. Moreover, in principle stations installed in a country are very much alike or perfectly identical, representing as a matter of fact a semi-professional seismic network..
It is then straightforward to wonder what is the role of the data recorded and stored by these instruments and especially what is the potential of these information. Are these instruments providing any additional information to the professional seismic networks ? Could they complement a professional database ?
In this paper a rough analysis of the data collected by a school network is analysed and compared with “official” data. It is shown that in some cases seismograms recorded from stations in schools can perform very well and their data could, under certain circumstances and with some limitations, be used instead of / in addition to professional data.PublishedTeatro Comunale F. Stabile, Potenza, Italy1.1. TTC - Monitoraggio sismico del territorio nazionaleope
Experimental estimation of energy dissipation in rocking masonry walls restrained by an innovative seismic dissipator (LICORD)
No full textThis paper presents an innovative anti-seismic device for controlling the out-of-plane rocking motion of masonry walls with traditional tie-rods, called LInear COntrolled Rocking Device (LICORD). LICORD is a low-impact box connected to the extremity of the traditional tie-rod designed to mitigate rocking for medium–high intensity earthquakes. Additionally, the paper widens the knowledge about the dynamic behavior of rocking walls through the interpretation of the results of an extensive experimental campaign performed on masonry specimens composed by clay brick and cementitious mortar. Firstly, the LICORD’s single components are tested to identify their stiffness and damping properties. Secondly, free vibration tests provide actual values of coefficients of restitution on free-standing walls and walls restrained by LICORD, where the walls vary for the height to thickness ratio. For the stockier wall, the ratio of experimental/analytical coefficient of restitution varies from 88 to 98%, whereas for the slender wall, the results are less scattered, with a minimum value of 95% and a maximum value of 96%. The restrained walls are characterized by coefficients of restitution from 5 to 25% less than the values found for unrestrained walls, depending on the equivalent viscous coefficient of the shock absorbers. Moreover, LICORD demonstrated to properly absorb and damp the oscillations of the wall and control its rocking motion, strongly reducing the number of impacts and the rotation amplitudes up to 70%. Considerations about the effect of one-sided motion on the assessment of coefficient of restitution are also given. The equivalent viscous damping coefficients are observed to be on the range 4% (unrestrained wall) and 7–20% for walls restrained by LICORD
- …
