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Parametric study on 2d effect on the seismic response of alluvial valleys
No full textThe local seismic response of an alluvial valley is influenced by many factors such as shape ratio, inclination of the edges, impedance and non-linear behaviour of soil. In this study, a parametric study was carried out to investigate the influence of 2D subsoil morphology on the amplification of the seismic motion at surface. To this aim a set of linear viscoelastic analyses was carried out on simplified 2D models, taking into account the shape of the valley, inclination of the edges, frequency of the excitation and impedance ratio. The results of the parametric study were interpreted in terms of spectral amplification factors evaluated considering both 2D and 1D conditions at some significant sections. The amplification factors calculated in the parametric study were compared with those computed on a real case history of alluvial valleys of Central Italy
Simulation of damages observed on buildings in aggregate after the 2016-2017 Central Italy earthquake accounting for site effects and soil-structure interaction.
No full textSimulation of damage observed on buildings in aggregate after the 2016-2017 Central Italy earthquake accounting for site effects and soil-structure interaction
No full textThe paper investigates the influence of site effects and soil-structure interaction on the response of buildings in aggregate in the historical centre of Visso, located in an alluvial valley in the Central Italy. The town was severely stricken by the Central Italy 2016/2017 seismic sequence and the subsequent inspections allowed the reconnaissance of damage suffered by the case study at hand. A monitoring system installed just out of the historical centre recorded the ground motion at Visso during the seismic sequence. Based on these records, the bedrock motion was then calculated through their deconvolution along the well characterized soil profile below the record station. The resulting signals were applied as input motions in linear equivalent site response analyses (i) of the 1D soil stratigraphy below the buildings in aggregate and (ii) of the whole 2D valley. In both cases, the subsoil model was inferred from the data gathered during the seismic microzonation study of the Visso village. The amplification of ground motion resulting from the 1D site response analysis is higher than that predicted by the 2D analysis along the same vertical. The whole aggregate was modelled in the Tremuri software through the equivalent frame approach and specific modelling strategies were adopted to account for the interaction among adjacent structural units. The model base was either completely restrained, to simulate the fixed-base conditions as typically assumed in the structural analysis, or endowed with springs, to simulate the effect of the soil compliance to the structural motion. Non-linear dynamic analyses were then performed on the fixed and complaint base models under the free-field motion obtained from the 1D and 2D site response analyses. The resulting damage patterns were compared to that detected on site. The comparison is satisfying only when the motion obtained from 2D site response is adopted as input motion and slightly improved when the compliant base conditions are considered
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Seismic microzonation of an alluvial valley hit by the 2016 central italy earthquake
No full textBetween August and November 2016, a seismic sequence, with magnitude, Mw, ranging between 5.9 and 6.5, struck the Central Italy. The paper discusses the results of the seismic microzonation study of two hamlets, Pretare and Piedilama, heavily damaged by this seismic sequence. The two villages are located in an alluvial valley, where large landslide bodies and loose soil layers cover a severely deformed Flysch bedrock. The experimental data collected during the field and laboratory investigations allow defining a 2D model of two representative cross sections of the valley. Their seismic response was evaluated carrying out nonlinear dynamic analyses. The response of the valley was synthesized in terms of amplification factor of the spectral acceleration, computed in three different ranges of periods. The results show that the maximum amplification factors are detected along the central part of the valley, due to both high impedance ratio and 2D basin effects
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Evaluation of Site Amplification for the Seismic Protection of a Strategic District in Naples
No full textSince the 1980s, a Business District is located in the eastern area of Naples. The first pioneer studies carried out in this area showed that a significant variability of site amplification can be predicted due to the morphology of seismic bedrock and to the presence of vanishing lenses of peat. More recently, the seismic vulnerability of the New Law Court was assessed adopting the hypothesis of 1D conditions for the seismic response analysis. This paper aims at verifying the reliability of this assumption, evaluating the 2D seismic site response of a representative geological section. Geotechnical characterization of the soil deposits has been carried out by integrating the available experimental data with literature data. Two suites of accelerograms have been considered as input motions, representative of ‘near field’ and ‘far field’ seismic events. Equivalent linear and non-linear 2D analyses have been carried out through a finite element and a finite difference code, respectively. Results provide insights on the non-linear soil behaviour of peat and allow for recognizing the limits and advantages of both adopted approaches. Finally, the comparison between the results of 2D and 1D analyses allows for highlighting the effects of focalization of seismic waves on the amplification of the ground motion at the surface
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