1,720,965 research outputs found
Assessment and seismic improvement with traditional and innovative technologies in the reuse design of San Benedetto Novello in Perugia
No full textExperimental, analytical and numerical analysis of the seismic behavior of Large Lightly R/C Walls cast with Wood Blocks System
No full textThe paper deals with the experimental research and theoretical and numerical analysis on panels made with the construction technology known as Large Lightly Reinforced Concrete Walls–Wood Blocks System (LLRCW–WBS). The results of a series of experimental tests performed on real scale panels subjected to vertical load and cyclic horizontal actions on their plane are presented. Theoretical and numerical analysis have been carried out to understand the experimental results and providing calculation models suitable for the seismic design of LLRCW–WBS panels. Theoretical procedures and numerical models allow to determine the main mechanical parameters characterizing the seismic capacity of the panels, that are strength, deformation capacity, dissipative capacity and collapse modes. Results from theoretical and numerical analysis show a good correspondence with experimental results
An innovative continuous Bayesian model updating method for base-isolated RC buildings using vibration monitoring data
No full textBase isolation is the most widespread passive control strategy for seismic protection of low- and medium-rise Reinforced Concrete (RC) buildings. The excellent performance of base-isolated structures just after construction is well recognized but their seismic behavior after a few operation years can be significantly modified, due to isolators’ aging. In this perspective, the availability of long-term vibration data allows to eventually assess the evolution of degradation and plan maintenance or replacement actions. This paper presents an innovative continuous Bayesian model updating method specific for base isolated buildings. In the proposed method, the Bayesian functions of the isolation system are periodically updated to account for daily measured data. The results of a comprehensive study on a base isolated three-stories RC school building, located in Bojano (Italy), are presented. The investigation comprises Ambient Vibration Testing (AVT), modal identification, installation of a continuous monitoring system and calibration of a Finite Element Model (FEM) of the isolated structure. In order to reduce the computational cost of the model updating procedure, a surrogate model is constructed and calibrated using the complete FEM of the structure through the Response Surface Methodology (RSM). The advantage of having long-term monitoring data on the results of the Bayesian model updating for base isolated structures is highlighted
Vertical collapse mechanisms in masonry buildings due to seismic vertical component
No full textThe acceleration histories recorded in the epicentral areas during the last earthquake in Central
Italy (2016-17) show very intense vertical components. During the post-earthquake damage assessment operations
in the epicentral areas, some damage frameworks different from those described in the literature have
been observed, with a macro-element collapse mode attributable to the action of the earthquake vertical component.
The paper presents some of these buildings characterized by the presence of horizontal cracks, by the
displacement of the highest levels, by vertical cracks in the sub-window walls. The masonry walls are undamaged
without the typical shear or flexure failure cracks and the lower levels do not show any damage. The
crack pattern and the associated collapse mechanisms cannot be included within the classic in-plane and outof-
plane mechanisms. A collapse mechanism characterized by the loss of vertical connection of entire structural
bodies is therefore hypothesized. The activation of this type of mechanism would seem to exclude the
formation of the classic collapse mechanisms on which the seismic capacity checks of the masonry structures
provided by the technical codes are based. A simplified linear kinematic analysis able to analyze the described
behavior is proposed and illustratively applied to a case study building. Criteria for the identification and verification
of the proposed mechanisms are described, with the aim to introduce the method in design codes
A Simplified Parametric Study on Occupant Comfort Conditions in Base Isolated Buildings under Wind Loading
Full text linkVibrations in buildings can cause occupant discomfort in the form of annoyance, headache, or sickness. While occupant comfort is considered in international standards regarding the design of high rise buildings against wind loading, it is neglected in the design of buildings with seismic protective base isolation systems. Nevertheless, due to their low flexibility, base isolated buildings can be prone to wind-induced vibrations, which makes occupant discomfort a potentially significant serviceability limit state. This paper presents a study on occupant comfort conditions in wind-excited base isolated buildings. A numerical simplified parametric procedure is proposed in order to evaluate the return period of wind events causing human discomfort. A parametric investigation is then presented to evaluate the effects of salient parameters on comfort conditions. The procedure is based on (i) the nonlinear dynamic analysis of the structure modeled as a single-degree-of-freedom oscillator with hysteretic base isolators, (ii) the digital generation of time histories of turbulent wind velocity, and (iii) comfort evaluations based on international standards. Results demonstrate that discomfort conditions can occur a few times in a year, depending upon the wind-exposure of the site, what suggests considering this serviceability limit state in the design of base isolated buildings
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Experimental vertical compression tests on reinforced concrete panels made with wood blocks system and theoretical evaluation of critical load.
No full textThe paper deals with the experimental and theoretical study of the behavior of panels made with large lightly reinforced concrete walls–wood blocks system (LLRCW– WBS). The results of a series of centered axial compression tests performed on slender and squat panels made with the above mentioned system are presented. The theoretical studies carried out in order to estimate the local and global buckling collapse load as a function of significant parameters are then introduced. Theoretical analyses have been conducted on the basis of already established studies aiming to produce appropriate calculation methods for
the design of LLRCW–WBS panels subjected to axial compressive actions. The results from theoretical analyses have been compared with those obtained from tests which resulted in an adequate correspondence
Variations on the Author
Full text link“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
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