Search results for "technical"
showing 10 items of 955 documents
The Effects of Structure on the One Dimensional Compression Behaviour of a Porous Calcarenite
2019
Human settlements built on weak rock deposits are often characterized by instabilities or collapse that may involve the underground cavities and consequently the above buildings. Underground calcarenite quarries in Marsala have been involved in a number of collapses that have seriously damaged numerous buildings. Unfortunately proper engineering solutions have not yet been identified according to the different and special cases and to the properties of this structured material. In order to investigate structure effects on the behaviour of the porous calcarenite of Marsala, this paper presents a comparison between the one dimensional compression behaviour of the intact rock and of the same w…
An experimental and constitutive investigation on the chemo-mechanical behaviour of a clay. In Bio- and Chemo- Mechanical Processes in Geotechnical E…
2014
Engineering issues for which the understanding of the chemo-mechanical behaviour of soils is relevant include wellbore stability problems, the salinification of groundwater, and nuclear waste storage. However, despite the vast number of situations in which couplings between chemistry and mechanics occur, the available constitutive models rely on limited experimental evidence. This paper presents the results of an experimental programme on the chemo-mechanical behaviour of a non-swelling illite. The osmotic suction is controlled through the ion concentration of sodium chloride in the pore water. Stress paths include mechanical loading at a constant osmotic suction, and an increasing osmotic …
Out-of-Plane fragility of In-Plane damaged unreinforced masonry infills in low rise reinforced concrete buildings
2022
Unreinforced masonry (URM) is commonly used to make infill walls in reinforced concrete (RC) frame buildings. Such infill walls are highly vulnerable to out-of-plane (OOP) seismic loading and this can result in huge economic losses and human casualties. Therefore, fragility assessment of URM infill walls under seismic loads is important in view of performing large-scale risk analysis. In this paper, OOP fragility functions are provided based on a numerical investigation supported by a macro-element model. The fragility is calculated assuming the uncertainty in the geometric and mechanical properties of infills instead of the variability in the seismic input. Further, the effect of in-plane …
Influence of wall-to-floor connections and pounding on pre- and post-diction simulations of a masonry building aggregate tested on a shaking table
2023
AbstractThis paper presents numerical simulations within the frame of the project SERA—AIMS (Seismic Testing of Adjacent Interacting Masonry Structures). The study includes blind pre-diction and post-diction stages. The former was developed before performing the shaking table tests at the laboratory facilities of LNEC (Lisbon), while the latter was carried out once the test results were known. For both, three-dimensional finite element models were prepared following a macro-modelling approach. The structure consisted of a half-scaled masonry aggregate composed by two units with different floor levels. Material properties used for the pre-diction model were based on preliminary tests previou…
Simulation of blind pre-diction and post-diction shaking table tests on a masonry building aggregate using a continuum modelling approach
2023
AbstractMasonry buildings of historical centres are usually organized within aggregates, whose structural performance against seismic actions is challenging to predict and constitutes still an open issue. The SERA—AIMS (Seismic Testing of Adjacent Interacting Masonry Structures) project was developed to provide additional experimental data by testing a half-scale, two-unit stone masonry aggregate subjected to two horizontal components of dynamic excitation. In this context, this paper investigates the reliability of the modelling approach and the assumptions adopted to generate a three-dimensional continuum finite element model. The work involves two stages, namely a blind pre-diction and a…
Sine cura. Verso il ri-ciclo dell'architettura del secondo Novecento
2019
Gli argomenti discussi nel saggio interrogano il destino che il Codice dei Beni Culturali (2004- 2011) determina per le opere del secondo Novecento. Nella costruzione del futuro di questi manufatti, che per funzione, tecnologia e cicli d’uso sono spesso segnati dall’obsolescenza e dall’abbandono, le ambiguità e le incongruenze delle attuali procedure legislative sollecitano profondamente il ruolo culturale delle esperienze di ricerca che usano metodologie meta progettuali. Il confronto fra alcuni casi italiani ed altri europei rimarca il ruolo del progetto nella costruzione di una prospettiva di tutela trasformativa per il costruito del secondo Novecento. Nel quadro di azione marcato dall’o…
A repository of fragments for agent systems design
2006
The creation of a new design process for a specific situation using the method engineering approach is based on the composition of a set of reusable method fragments. The request for these reusable method fragments leads to the need for a repository containing standardized fragments that can be easily selected and assembled in new design processes. In this work we present a definition of method fragment coming from the work of the FIPA Technical Committee Methodology and a repository where fragments are classified according to the specific process component (activity, process role, and work product) they underpin and on the specific MAS Metamodel element(s) they work on.
Investigation on Cascode Devices for High Frequency Electrical Drives Applications
2019
In the last years a widespread development in the market of electrical drives employing high-speed electrical machines has occurred in various industrial fields, due to the extremely high power density that can be reached. Nevertheless, to maintain output power quality without using bulky filtering networks, DC-AC converters should be controlled by means of higher PWM switching frequencies. New switching device technologies, such as Field Effect Transistors based on SiC and GaN, are therefore gathering momentum in order to comply with the higher working frequencies. To operate under high frequencies and at the same time at high voltage levels, alternative circuital configurations for switch…
Istruttoria tecnico-scientifica nel giudizio a quo e giudizio di legittimità costituzionale: il caso dell’obbligo vaccinale nella decretazione d’urge…
2022
Muovendo dall’ordinanza n. 38 del 2022 del Consiglio di giustizia amministrativa per la Regione siciliana (CGARS), il contributo si sofferma a) sull’estensione per analogia degli obblighi vaccinali; b) su oscurità ed incoerenze della disciplina sugli obblighi vaccinali in tema di accesso alle strutture socio-sanitarie. Il contributo si incentra poi sull'istruttoria tecnico-scientifica e la motivazione sulla non manifesta infondatezza delle questioni di legittimità costituzionale aventi ad oggetto la disciplina sull'obbligo vaccinale e sugli aspetti problematici dell'ordinanza di rimessione del CGARS.
Quattro nodi maggiori del Sistema nazionale di istruzione in Italia
2021
Teacher training, professional qualification and recruitment. Rethinking of school autonomy as part of a more ambitious administration reform. The birth rate as an opportunity to use economies in challenging policies. The strengthening of post-secondary but not university higher technical training. There are four goals on which the Italian school needs urgent re- form measures to improve its performance. However, it is necessary not to pay attention only to the “internal voices”.