Marco Uzielli - Academia.edu (original) (raw)

Papers by Marco Uzielli

Research paper thumbnail of Quantitative modelling of spatial variability of piezocone data from Venice lagoon silty soils

CRC Press eBooks, Jun 7, 2022

As geotechnical research and design codes rely increasingly on probabilistic approaches, site cha... more As geotechnical research and design codes rely increasingly on probabilistic approaches, site characterization should also be conducted in the light of the explicit quantification of the uncertainty and spa tial variability in soil properties. This paper provides a practical case-study application of spatial variability analysis of piezocone data obtained at a test site in the Lagoon surrounding the historic city of Venice, in NorthEastern Italy, where unusually dense and regularly spaced CPT test data were available. Empirical semivariograms are calculated for cone resistance, sleeve friction, and porewater pressure, along with the soil behavior classification index obtained from these measurements at a set of reference measurement depths. A number of theoretical semivariogram models are fitted comparatively and best-fit models are selected based on objective criteria and subjective judgment. Characteristic semivariogram parameters, providing informa tion on correlation distance and small-scale variability, are retrieved. Modeling options are explained and results are analyzed and assessed critically.

Research paper thumbnail of Statistical calibration of two-dimensional seismic aggravation effects for homogeneous basins

Soil Dynamics and Earthquake Engineering

Research paper thumbnail of Time capsule for geotechnical risk and reliability

Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards

Research paper thumbnail of Some Observations on Assessment of Gaussianity for Correlated Profiles

GeoCongress 2006, 2006

The classical Anderson-Darling test for Gaussianity cannot be applied on correlated data. It is p... more The classical Anderson-Darling test for Gaussianity cannot be applied on correlated data. It is possible to circumvent correlation by resampling the data at wider spacing. A simple resampling criterion is developed using digitally simulated standard Gaussian realizations following a single exponential correlation structure. The effects of resampling on Gaussianity assessment are assessed on actual normalized cone tip resistance profiles from highly homogeneous soil units.

Research paper thumbnail of Ricostruzione stratigrafica da prove CPT meccaniche nell’area portuale di Gioia Tauro mediante tecniche di clustering e fuzzy

Nella presente sintesi sono riassunti i risultati parziali di una ricerca inerente l'applicazione... more Nella presente sintesi sono riassunti i risultati parziali di una ricerca inerente l'applicazione di procedure di elaborazione statistiche e tecniche di soft computing di dati geotecnici finalizzata alla caratterizzazione stratigrafica di siti nei quali siano state eseguite prove penetrometriche statiche. Introduzione La prova penetrometrica statica (CPT) viene impiegata sempre più frequentemente per la caratterizzazione stratigrafica e geotecnica, grazie alla sua maggiore precisione ed accuratezza rispetto ad altre indagini in sito ed alla misura continua, con la profondità, dei valori di resistenza del terreno. I dati penetrometrici disponibili sono sovente riferiti a campagne di prove eseguite con penetrometro meccanico, meno affidabili rispetto a prove effettuate con il penetrometro elettrico o con il piezocono, a causa, tra l'altro, del maggiore intervallo tra letture consecutive, delle maggiori incertezze sui valori misurati, e di uno sfasamento maggiore tra le misure della resistenza di punta q c e della resistenza laterale f s. La minore affidabilità della prova meccanica e la necessità di utilizzarne i risultati nella progettazione, suggeriscono l'utilizzo ed il confronto di più tecniche di interpretazione finalizzate alla caratterizzazione stratigrafica e geotecnica. Tali procedure possono consistere in: 1) analisi visuale dei dati; 2) carte di classificazione empiriche; 3) metodi statistici univariati e multivariati; 4) tecniche fuzzy o procedure più complesse, quali reti neurali. Il presente lavoro si propone di indagare l'applicabilità di tecniche di classificazione dei terreni e ricostruzione stratigrafica da prove CPT meccaniche basate sul clustering e sugli insiemi fuzzy. A tal fine sono state considerate 24 prove CPT meccaniche relative a campagne di indagini condotte nella zona portuale di Gioia Tauro (RC). Aspetti geologici e geotecnici del sito in esame L'area zona portuale di Gioia Tauro (limitatamente ai primi 20 m esplorati con le prove CPT) è caratterizzata da strati più superficiali costituiti prevalentemente da terreni granulari saturi, salvo uno strato di riporto decimetrico. Procedendo verso il basso, si individuano tre formazioni: depositi eolici rimaneggiati di sabbie sciolte da grossolane a medie (di spessore variabile tra 3 e 5 m); ghiaie poligeniche sabbiose litorali e fluviali di spesso-Facciorusso e Uzielli

Research paper thumbnail of Approaches for assessment of vulnerability of critical infrastructures to weather-related hazards

Research paper thumbnail of Probabilistic evaluation of snow avalanche runout

Research paper thumbnail of Variabilità geotecnica e affidabilità della sperimentazione

Seminario di studio sulla caratterizzazione geotecnica dei terreni in relazione a problemi di ingegneria civile, 2006

La qualità del progetto geotecnico, in termini di sicurezza, funzionalità, durabilità, realizzabi... more La qualità del progetto geotecnico, in termini di sicurezza, funzionalità, durabilità, realizzabilità ed economicità, è determinata da una molteplicità di elementi. L'evento della progettazione può essere infatti scomposto concettualmente nelle seguenti fasi: analisi e ...

Research paper thumbnail of Comparative CPT-based classification of Cooper Marl

Research paper thumbnail of Statistical identification of homogeneous soil layers in Venice lagoon soils

ABSTRACT The paper addresses the identification of soil units which are physically homogeneous in... more ABSTRACT The paper addresses the identification of soil units which are physically homogeneous in terms of hydro-mechanical response to cone penetration. A moving-window statistical procedure is applied to a number of CPTU-related parameters provided for the Malamocco site in the Venice lagoon. Example criteria for the assessment of homogeneity of soil units are provided. Subjective and objective aspects of the proce-dure are discussed.

Research paper thumbnail of Bayesian prediction of peak resistance of a spudcan penetrating sand-over-clay

Géotechnique, 2018

Assessing the potential for a punch-through failure during spudcan installation in sand-over-clay... more Assessing the potential for a punch-through failure during spudcan installation in sand-over-clay is crucial for reducing risk in the operations of mobile jack-up platforms. Typically, in the offshore industry, the peak penetration resistance and the depth at which it occurs are determined deterministically without rigorously considering the uncertainties in the soil. This paper proposes a probabilistic approach to estimate the peak resistance and the corresponding depth, as well as a Bayesian method of incorporating installation data to update the predictions. Instead of a single value in the deterministic analysis, a range of the potential peak resistances and depths can be estimated by accounting for the uncertainties in the soil, the spudcan's geometry and in the calculation method itself, with a database of 66 geotechnical centrifuge tests characterising the model. This prior probability is then updated using the monitored data, allowing a real-time update of the probabilit...

Research paper thumbnail of Uncertainty-based characterisation of Troll marine clay

Proceedings of the Second International Workshop on Characterisation and Engineering Properties of Natural Soils, Singapore, 29 November-1 December 2006, 2006

Research paper thumbnail of FEM Geotechnical Analysis of the Seismic Damage to the Church of S. Filippo in Nocera Umbra during the September 26, 1997 Seismic Sequence

Maugeri e Nova (a cura di): Geotechnical …, 2003

Research paper thumbnail of Investigation of correlation structures and weak stationarity using the CPT soil behavior classification index

Research paper thumbnail of An experience of knowledge co-production for setting up landslide risk management processes in a critical infrastructure: the case of Campania Region (Southern Italy)

Research paper thumbnail of Interactive comment on “ Temporal evolution of landslide hazard for a road infrastructure in the Municipality of Nocera Inferiore , Italy , under the effect of climate change ” by Marco Uzielli et al

Comment 2.1 Definition of the statistical model: the authors use two variables derived by rainfal... more Comment 2.1 Definition of the statistical model: the authors use two variables derived by rainfall measurements as proxy of landslide triggering: 1-day rainfall and 59-day rainfall. The choice of these variables is briefly mentioned by the authors (page 6 – lines 7-9) but is totally unclear. Since the choice of the proxy variables is essential in the definition of probability of landslides triggering, this part deserves more space and more details.

Research paper thumbnail of Bayesian Prediction of Punch-Through Probability for Spudcans in Stiff-over-Soft Clay

Research paper thumbnail of A Web-Based Landslide Risk Mitigation Portal

The mitigation of landslide risk to human-valued physical and non-physical assets is a fundamenta... more The mitigation of landslide risk to human-valued physical and non-physical assets is a fundamental component in the disaster risk management cycle Open image in new window . The reduction of risk can be pursued through the selection, planning and implementation of suitable mitigation measures and/or actions. The selection of the most appropriate mitigation measures is a complex process which depends on both the characteristics of the expected landslide event and the potential impacts on the physical, economic, environmental, cultural and societal human-valued assets. Each risk mitigation effort is thus markedly case- and site-specific. A web-based portal is in course of development within the Norwegian research project Klima 2050. The project is aimed at reducing the risks associated with climate changes and enhanced precipitation and flood water exposure within the built environment. The portal implements the analytic hierarchy process (AHP) for the purpose of selecting the most ap...

Research paper thumbnail of A framework for the design of vertically loaded piles in spatially variable soil

Computers and Geotechnics

Research paper thumbnail of Probabilistic Estimation of Linear and Volumetric Strain Thresholds for Italian Clays

Proceedings of the 29th European Safety and Reliability Conference (ESREL)

Research paper thumbnail of Quantitative modelling of spatial variability of piezocone data from Venice lagoon silty soils

CRC Press eBooks, Jun 7, 2022

As geotechnical research and design codes rely increasingly on probabilistic approaches, site cha... more As geotechnical research and design codes rely increasingly on probabilistic approaches, site characterization should also be conducted in the light of the explicit quantification of the uncertainty and spa tial variability in soil properties. This paper provides a practical case-study application of spatial variability analysis of piezocone data obtained at a test site in the Lagoon surrounding the historic city of Venice, in NorthEastern Italy, where unusually dense and regularly spaced CPT test data were available. Empirical semivariograms are calculated for cone resistance, sleeve friction, and porewater pressure, along with the soil behavior classification index obtained from these measurements at a set of reference measurement depths. A number of theoretical semivariogram models are fitted comparatively and best-fit models are selected based on objective criteria and subjective judgment. Characteristic semivariogram parameters, providing informa tion on correlation distance and small-scale variability, are retrieved. Modeling options are explained and results are analyzed and assessed critically.

Research paper thumbnail of Statistical calibration of two-dimensional seismic aggravation effects for homogeneous basins

Soil Dynamics and Earthquake Engineering

Research paper thumbnail of Time capsule for geotechnical risk and reliability

Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards

Research paper thumbnail of Some Observations on Assessment of Gaussianity for Correlated Profiles

GeoCongress 2006, 2006

The classical Anderson-Darling test for Gaussianity cannot be applied on correlated data. It is p... more The classical Anderson-Darling test for Gaussianity cannot be applied on correlated data. It is possible to circumvent correlation by resampling the data at wider spacing. A simple resampling criterion is developed using digitally simulated standard Gaussian realizations following a single exponential correlation structure. The effects of resampling on Gaussianity assessment are assessed on actual normalized cone tip resistance profiles from highly homogeneous soil units.

Research paper thumbnail of Ricostruzione stratigrafica da prove CPT meccaniche nell’area portuale di Gioia Tauro mediante tecniche di clustering e fuzzy

Nella presente sintesi sono riassunti i risultati parziali di una ricerca inerente l'applicazione... more Nella presente sintesi sono riassunti i risultati parziali di una ricerca inerente l'applicazione di procedure di elaborazione statistiche e tecniche di soft computing di dati geotecnici finalizzata alla caratterizzazione stratigrafica di siti nei quali siano state eseguite prove penetrometriche statiche. Introduzione La prova penetrometrica statica (CPT) viene impiegata sempre più frequentemente per la caratterizzazione stratigrafica e geotecnica, grazie alla sua maggiore precisione ed accuratezza rispetto ad altre indagini in sito ed alla misura continua, con la profondità, dei valori di resistenza del terreno. I dati penetrometrici disponibili sono sovente riferiti a campagne di prove eseguite con penetrometro meccanico, meno affidabili rispetto a prove effettuate con il penetrometro elettrico o con il piezocono, a causa, tra l'altro, del maggiore intervallo tra letture consecutive, delle maggiori incertezze sui valori misurati, e di uno sfasamento maggiore tra le misure della resistenza di punta q c e della resistenza laterale f s. La minore affidabilità della prova meccanica e la necessità di utilizzarne i risultati nella progettazione, suggeriscono l'utilizzo ed il confronto di più tecniche di interpretazione finalizzate alla caratterizzazione stratigrafica e geotecnica. Tali procedure possono consistere in: 1) analisi visuale dei dati; 2) carte di classificazione empiriche; 3) metodi statistici univariati e multivariati; 4) tecniche fuzzy o procedure più complesse, quali reti neurali. Il presente lavoro si propone di indagare l'applicabilità di tecniche di classificazione dei terreni e ricostruzione stratigrafica da prove CPT meccaniche basate sul clustering e sugli insiemi fuzzy. A tal fine sono state considerate 24 prove CPT meccaniche relative a campagne di indagini condotte nella zona portuale di Gioia Tauro (RC). Aspetti geologici e geotecnici del sito in esame L'area zona portuale di Gioia Tauro (limitatamente ai primi 20 m esplorati con le prove CPT) è caratterizzata da strati più superficiali costituiti prevalentemente da terreni granulari saturi, salvo uno strato di riporto decimetrico. Procedendo verso il basso, si individuano tre formazioni: depositi eolici rimaneggiati di sabbie sciolte da grossolane a medie (di spessore variabile tra 3 e 5 m); ghiaie poligeniche sabbiose litorali e fluviali di spesso-Facciorusso e Uzielli

Research paper thumbnail of Approaches for assessment of vulnerability of critical infrastructures to weather-related hazards

Research paper thumbnail of Probabilistic evaluation of snow avalanche runout

Research paper thumbnail of Variabilità geotecnica e affidabilità della sperimentazione

Seminario di studio sulla caratterizzazione geotecnica dei terreni in relazione a problemi di ingegneria civile, 2006

La qualità del progetto geotecnico, in termini di sicurezza, funzionalità, durabilità, realizzabi... more La qualità del progetto geotecnico, in termini di sicurezza, funzionalità, durabilità, realizzabilità ed economicità, è determinata da una molteplicità di elementi. L'evento della progettazione può essere infatti scomposto concettualmente nelle seguenti fasi: analisi e ...

Research paper thumbnail of Comparative CPT-based classification of Cooper Marl

Research paper thumbnail of Statistical identification of homogeneous soil layers in Venice lagoon soils

ABSTRACT The paper addresses the identification of soil units which are physically homogeneous in... more ABSTRACT The paper addresses the identification of soil units which are physically homogeneous in terms of hydro-mechanical response to cone penetration. A moving-window statistical procedure is applied to a number of CPTU-related parameters provided for the Malamocco site in the Venice lagoon. Example criteria for the assessment of homogeneity of soil units are provided. Subjective and objective aspects of the proce-dure are discussed.

Research paper thumbnail of Bayesian prediction of peak resistance of a spudcan penetrating sand-over-clay

Géotechnique, 2018

Assessing the potential for a punch-through failure during spudcan installation in sand-over-clay... more Assessing the potential for a punch-through failure during spudcan installation in sand-over-clay is crucial for reducing risk in the operations of mobile jack-up platforms. Typically, in the offshore industry, the peak penetration resistance and the depth at which it occurs are determined deterministically without rigorously considering the uncertainties in the soil. This paper proposes a probabilistic approach to estimate the peak resistance and the corresponding depth, as well as a Bayesian method of incorporating installation data to update the predictions. Instead of a single value in the deterministic analysis, a range of the potential peak resistances and depths can be estimated by accounting for the uncertainties in the soil, the spudcan's geometry and in the calculation method itself, with a database of 66 geotechnical centrifuge tests characterising the model. This prior probability is then updated using the monitored data, allowing a real-time update of the probabilit...

Research paper thumbnail of Uncertainty-based characterisation of Troll marine clay

Proceedings of the Second International Workshop on Characterisation and Engineering Properties of Natural Soils, Singapore, 29 November-1 December 2006, 2006

Research paper thumbnail of FEM Geotechnical Analysis of the Seismic Damage to the Church of S. Filippo in Nocera Umbra during the September 26, 1997 Seismic Sequence

Maugeri e Nova (a cura di): Geotechnical …, 2003

Research paper thumbnail of Investigation of correlation structures and weak stationarity using the CPT soil behavior classification index

Research paper thumbnail of An experience of knowledge co-production for setting up landslide risk management processes in a critical infrastructure: the case of Campania Region (Southern Italy)

Research paper thumbnail of Interactive comment on “ Temporal evolution of landslide hazard for a road infrastructure in the Municipality of Nocera Inferiore , Italy , under the effect of climate change ” by Marco Uzielli et al

Comment 2.1 Definition of the statistical model: the authors use two variables derived by rainfal... more Comment 2.1 Definition of the statistical model: the authors use two variables derived by rainfall measurements as proxy of landslide triggering: 1-day rainfall and 59-day rainfall. The choice of these variables is briefly mentioned by the authors (page 6 – lines 7-9) but is totally unclear. Since the choice of the proxy variables is essential in the definition of probability of landslides triggering, this part deserves more space and more details.

Research paper thumbnail of Bayesian Prediction of Punch-Through Probability for Spudcans in Stiff-over-Soft Clay

Research paper thumbnail of A Web-Based Landslide Risk Mitigation Portal

The mitigation of landslide risk to human-valued physical and non-physical assets is a fundamenta... more The mitigation of landslide risk to human-valued physical and non-physical assets is a fundamental component in the disaster risk management cycle Open image in new window . The reduction of risk can be pursued through the selection, planning and implementation of suitable mitigation measures and/or actions. The selection of the most appropriate mitigation measures is a complex process which depends on both the characteristics of the expected landslide event and the potential impacts on the physical, economic, environmental, cultural and societal human-valued assets. Each risk mitigation effort is thus markedly case- and site-specific. A web-based portal is in course of development within the Norwegian research project Klima 2050. The project is aimed at reducing the risks associated with climate changes and enhanced precipitation and flood water exposure within the built environment. The portal implements the analytic hierarchy process (AHP) for the purpose of selecting the most ap...

Research paper thumbnail of A framework for the design of vertically loaded piles in spatially variable soil

Computers and Geotechnics

Research paper thumbnail of Probabilistic Estimation of Linear and Volumetric Strain Thresholds for Italian Clays

Proceedings of the 29th European Safety and Reliability Conference (ESREL)