1,721,238 research outputs found
The Treporti test site: exploring the behaviour of the silty soils of the Venetian Lagoon
No full textSimplified failure load envelopes for shallow foundation on dense sand
No full textPrediction of the ultimate load capacity of shallow, sand supported foundations carrying vertical (Y), horizontal (H) and moment (M) loads is a fundamental offshore engineering problem. The paper demonstrates how the complete failure envelope of such a foundation, represented by a system of parabolas and rotated ellipses, can be transformed into either a 45° inclined straight line or a unit circle by referring the applied loads to an origin located below the foundation centreline. The conjugate transformation applied to the corresponding displacements generates a symmetry amongst them, for symmetrical load paths, not otherwise apparent. Extensive, model-scale, experimental data are presented that provide strong support for the simple, transformed failure-envelopes
On the Evaluation of Indirect Simulations Performance of Multi-parametrical Transient Seepage Models in River Embankments
No full textThe design and vulnerability assessment of earth-filled water retainingstructures require the elaboration of reliable seepage analyses. Model predictions,however, can result highly unreliable because of poor parameter estimations. Toaddress this issue, inverse modelling techniques can be implemented, incorporat-ing observations of on-going processes into direct simulations. With reference toriver embankments, time series of the monitored soil water content and pore wa-ter pressure can be helpful for a proper calibration of hydraulic and retentionproperties of the materials involved in the seepage problem. For the present study,the Levenberg-Marquardt algorithm implemented in the commercial code Hy-drus 2D by Pc-Progress has been applied for the optimization procedure of aninstrumented river embankment section along the river Secchia (Modena, Italy),making use of observational data. The seepage analysis is carried out consideringvarious assumptions on the series of monitoring data, weighing distributions andoptimized parameters combinations. The study aims to analyze an effective ap-plication of combined qualitative and quantitative methodologies for the perfor-mance evaluation of indirect simulations in the transient multi-parametricalmodel under investigation, in order to estimate the optimal set of parameters as afunction of the pursued aim of the modelling
Geotechnical Engineering in Multidisciplinary Research: from Microscale to Regional Scale
No full textTen years after the successful conference held in Bari, the VI Italian Conference of Researchers in Geotechnical Engineering (CNRIG) took place at the Auditorium of Department of Arts of the Alma Mater Studiorum in Bologna on 22-23 September 2016. The event was organized by the Geotechnical Engineering Group of the University of Bologna in collaboration with the National Group of Geotechnical Engineering (GNIG) and under the auspices of the Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) of the University of Bologna.
The overall theme of the Conference was "Geotechnical Engineering in Multidisciplinary Research: from Microscale to Regional Scale", a purposely broad ‘hot’ topic that provided a wide scope for participation from the many disciplines interacting on various issues with Geotechnical Engineering at different scales of analysis.
As tradition of such conferences which foster a lively debate on recent research advancements, the event provided great opportunities for participants to share up-to-date knowledge, new ideas and experiences in Geotechnical Engineering, as well as to discuss current research prospects and potential future collaborations.
Being the 6th conference of the CNRIG series, some valuable traditions were maintained while a few significant novelties were introduced. The key innovation of this edition was undoubtedly represented by its international vocation, which implied the adoption of English language throughout and the publication of the proceedings in the highly recognized, open access platform Procedia Engineering, thus allowing other readers around the world to benefit from the outcomes of the Conference.
From the initially submitted 109 abstracts, 92 papers were finally accepted for publication. The Conference Organizing Committee was especially pleased with the unprecedented large number of high quality contributions submitted, exceeding all expectations and including the extensive presence of co-authors from interacting disciplines. As a further element of novelty, about 14% of the published papers included non-Italian Authors. The participation of delegates from outside Italy was most welcome and their contributions made CNRIG a more fruitful and international event.
The papers were sorted out into three general subject areas, according to the general theme of the Conference: 1) from Microscale to Macroscale, 2) from Macroscale to Boundary Value Problems, 3) from Boundary Value Problems to Regional Scale.
An enormous effort was made to provide the Authors with a rigorous and fair review of the papers. We are very grateful to the Scientific Committee, the Organizing Committee and, in particular, to the tireless publication team for their dedicated work and for ensuring such a high quality publication.
Finally, many thanks to all the Authors for their contribution to this Proceedings volume, for their initiative and enthusiasm. We do hope you will find its contents of valuable and long lasting use
Caisson Foundations for Competitive Offshore wind Farms in ITALY
No full textAbstractThe research presented in the paper moves from the results of a feasibility study recently carried out for the development of an offshore wind farm off the cost of Rimini, in the Northern Adriatic Sea. The work, based on in-situ measurements of the environmental conditions, assessed the suitability of the considered area for the development of a relatively large wind farm, although at the profitability limit. The study has considered 60 offshore wind turbines installed on monopiles, as they are, at present, the most common solution and a quantification of the investment costs could be reliably completed. With reference to such case, the paper addresses the use of caisson foundations, a convenient alternative to monopiles in water of shallow to intermediate depth, with the final aim of improving the overall cost-effectiveness of the investment
Assessing River Embankment Stability Under Transient Seepage Conditions
No full textAbstractThe evaluation of riverbank stability is a fundamental problem in flood risk management, representing a critical task for engineering practice. Soil heterogeneity together with initial and boundary conditions are among the crucial issues that should be considered to obtain an accurate solution of the problem. Generally, attention and efforts are mostly devoted to the soil characterization, the hydrometric level forecasts and the estimation of the rainfall intensity, while in situ measurements usually receive less attention. Nevertheless, suction and soil water content have a strong influence on the reliability of seepage and stability analyses. A preliminary study aiming at the design of a monitoring system for the measurement of soil moisture and suction in the unsaturated silty soils of a river embankment has been carried out, with the purpose of linking the collected data to the boundary conditions and hence obtaining a more accurate estimate of the riverbank probability of failure. Furthermore, a general outline of the research project, its methodology and application are presented in the paper
Preface
No full textTen years after the successful conference held in Bari, the VI Italian Conference of Researchers in Geotechnical
Engineering (CNRIG) took place at the Auditorium of Department of Arts of the Alma Mater Studiorum in Bologna
on 22-23 September 2016. The event was organized by the Geotechnical Engineering Group of the University of
Bologna in collaboration with the National Group of Geotechnical Engineering (GNIG) and under the auspices of
the Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) of the University of
Bologna. The overall theme of the Conference was "Geotechnical Engineering in Multidisciplinary Research: from
Microscale to Regional Scale", a purposely broad ‘hot’ topic that provided a wide scope for participation from the
many disciplines interacting on various issues with Geotechnical Engineering at different scales of analysis.
As tradition of such conferences which foster a lively debate on recent research advancements, the event
provided great opportunities for participants to share up-to-date knowledge, new ideas and experiences in
Geotechnical Engineering, as well as to discuss current research prospects and potential future collaborations
Metodologie di analisi per la valutazione della stabilità di argini fluviali in condizioni di flusso transitorio
No full textUn’accurata stima delle condizioni di stabilità di argini fluviali rappresenta un problema di notevole interesse
nell’ambito della gestione e pianificazione territoriale, con un diretto e significativo impatto nei processi di
valutazione del rischio idrogeologico. Pur limitandosi ai meccanismi di collasso connessi all’insorgenza di
fenomeni di instabilità globale, numerose sono le tematiche di interesse geotecnico coinvolte nella risoluzione di
tale problema; fra queste, le condizioni di parziale saturazione dei terreni costituenti il rilevato arginale, aventi
significativo impatto nella risposta idro-meccanica dell’opera in terra e presenti durante l’intera vita utile.
Inoltre, le condizioni di flusso transitorio associate ai moti di filtrazione che si sviluppano nel terreno arginale e
di fondazione risultano di non semplice descrizione, anche in relazione alla variabilità temporale delle condizioni
al contorno (di tipo atmosferico ed idraulico) ed alle incertezze associate alla conoscenza sia dello stato di
saturazione che delle proprietà idrauliche e di ritenzione del terreno. Queste, unite all’eterogeneità intrinseca dei
suoli, implica necessariamente l’adozione di approcci probabilistici, complicando certamente la definizione di
criteri sicurezza nei confronti dell’insorgenza di possibili meccanismi di collasso. Uno studio comprensivo delle
varie problematiche associate alla valutazione della stabilità di argini fluviali in condizioni di flusso transitorio è
stato condotto al fine di esplorare ed approfondire varie metodologie di analisi. I differenti approcci, nel seguito
brevemente descritti, si distinguono in base al grado di approfondimento e di dettaglio dei modelli, all’onere
computazionale e di calcolo richiesto ed alla tipologia di informazioni e dati di input a disposizione per la
risoluzione del problema in esame. Nella presente nota, infine, varie indicazioni son fornite sulla base delle
evidenze e dei risultati raccolti, con lo scopo di fornire un utile riferimento all’attuale pratica ingegneristica e di
investigare nel dettaglio le varie problematiche geotecniche coinvolte
STRUMENTO DI VERIFICA DEL GRADO DI SATURAZIONE DI UN GRUPPO SENSORE DI PRESSIONE DI UN PIEZOCONO, E METODO PER EFFETTUARE TALE VERIFICA
No full textL’invenzione ha ad oggetto uno strumento di verifica del grado di saturazione di un gruppo sensore di pressione di un piezocono, e un metodo per effettuare tale verifica. Il metodo e l'apparecchiatura stabiliscono un criterio quantitativo per definire il grado di saturazione della punta di un piezocono, e conseguentemente l’affidabilità delle misure ottenute. La procedura, da realizzarsi prima della prova, può efficacemente essere utilizzata anche al termine di questa, al fine di verificare l’insorgere di eventuali fenomeni di desaturazione nel corso della prova, dovuti all’attraversamento di strati di terreno non saturi o per venute di gas
Geotechnical Investigations and Monitoring of the Archaeological Site of Santa Croce in Ravenna (Italy)
Full text linkThe city of Ravenna, in northern Italy, is worldwide famous for the well-preserved late Roman and Byzantine architectures characterized by fabulous mosaics that have earned the UNESCO World Heritage status. The constantly growing attention towards their conservation has promoted research activities that focus on the effect of the considerable cumulated land subsidence on their current conditions. Today, the sum of long-lasting natural and more recent anthropogenic subsidence has brought the level of such ancient archaeological sites and monuments well below the current position of the phreatic water table, still close to the current ground surface of the city centre, as it is the case of the Santa Croce church and its archeologic area. The Church, dating back to the 5 th Century AD, is surrounded by ancient Roman floor mosaics, located ~3.2 m from the main street level. In this site, a pumping system must permanently operate to lift to the external sewage network the water collected from the local subsoil by means of a rather old and no longer efficient drainage system. A geotechnical investigation campaign was carried out in 2022, together with the installation of a new piezometric monitoring system, with the aim of investigating the shallow aquifers underneath the monuments. Relevant data interpretation will enable to better understand the current situation and, above all, to devise a proper solution which can combine the long-term conservation of the area with its usability
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