Italian Geotechnical Journal (Rivista Italiana di Geotecnica), 1998
The present paper reports the analyses performed to investigate the influence of factors such as ... more The present paper reports the analyses performed to investigate the influence of factors such as the rock mass quality and the in situ stress state on the deformational behaviour of rock masses. New correlations among the deformability modulus, the RMR index and the modulus ratio have been obtained from the analysis of a great number of case records. The comparison of these correlations with others, already established, allows useful considerations concerning the use of empirical approaches. Finally, the influence of the confining stress state on the rock mass deformability has been proved and assessed. Il presente articolo riporta le analisi svolte al fine di valutare l\u2019influenza che fattori quali la qualit\ue0 dell\u2019ammasso roccioso e lo stato di sforzo in sito hanno sul comportamento deformativo dell\u2019ammasso stesso. L\u2019elaborazione e l\u2019interpretazione di numerosi dati ricavati dalla letteratura, relativi alle propriet\ue0 di ammassi rocciosi in cui sono state realizzate opere di ingegneria, ha consentito di ottenere nuove correlazioni tra il valore del modulo di deformabilit\ue0 dell\u2019ammasso roccioso, l\u2019indice RMR e il Rapporto di Modulo del materiale roccioso. Esse sono state confrontate con analoghe correlazioni gi\ue0 ben consolidate e di pratico utilizzo, pervenendo a utili considerazioni sull\u2019applicabilit\ue0 delle relazioni empiriche. \uc8 stato possibile accertare infine, qualitativamente e quantitativamente, l\u2019influenza esercitata dall\u2019azione di confinamento dovuta allo stato di sforzo in sito sul modulo di deformabilit\ue0 dell\u2019ammasso roccioso
Proceedings of the Institution of Civil Engineers, 2005
Understanding the principal features of soil stiffness has been one of the major achievements of ... more Understanding the principal features of soil stiffness has been one of the major achievements of geotechnical engineering over the past 30 years. The study of modulus degradation is now one of the main research areas. Understanding non-linearity is essential in foundation design for accurate and reliable evaluation of ground movements. This paper looks at the problem of assessing of deep foundation settlements and describes two approaches developed to enable designers to take soil–foundation non-linear behaviour into account. The first provides in-field stiffness parameters evaluated by back-analysis of full-scale piles. The second involves deducting the behaviour of the soil interacting with a foundation from degradation curves characterising the soil stiffness.
... p. 149-157. Authors: Berardi, R. LANCELLOTTA, R. Publication Date: 1991. Serial: ... Geotechn... more ... p. 149-157. Authors: Berardi, R. LANCELLOTTA, R. Publication Date: 1991. Serial: ... Geotechnology; Highways. Last Modified: Mar 31 1992 12:00AM. More Articles from this Serial Issue: EFFECTS OF DRYING ON THE ENGINEERING BEHAVIOUR OF COCHIN MARINE CLAYS. ...
The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical ... more The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical properties and, consequently, to improve the footing load carrying capacity reducing the associated settlements. Simplified approaches generally rely on corrective factors, allowing the analysis of reinforced foundation starting from the knowledge of the performance of the unreinforced one. A critical aspect refers to the applied load: for footings subjected to inclined loads, it is not possible to assess the bearing capacity and the displacements by using simplified methods referred to vertical loading conditions. The paper reports the results of numerical FEM analyses, aimed to investigate the limit conditions for a shallow strip footing subjected to inclined load and to highlight how the failure envelope (in the plane of vertical V and horizontal H load components) of the reinforced foundation modifies (in size and shape) in comparison with that of the unreinforced one. The use of the failure envelope approach, instead of the usual bearing capacity corrective factors, allows a more rational analysis of the interaction phenomena occurring in the reinforced soil. The numerical analyses enable to consider different cases as to the reinforcement arrangements and types
Innovative researches developed by the Authors are described in order to demonstrate the usefulne... more Innovative researches developed by the Authors are described in order to demonstrate the usefulness of GIS (Geographic Information System) in support of geotechnical analysis, with particular reference to risk zoning and mitigation and to the monitoring of slopes. A multivariate statistical procedure for the estimation of landslide susceptibility, an automatic procedure providing maps of the countermeasures to recommend for slope stabilization and reinforcement, and a cognitive/predictive hydrological-geotechnical (IHG) model coupled with a dense, low-cost network of sensors are presented. The contribution of GIS environment to the analysis and prevention of landslide susceptibility, both at wide area and at local scale, as well as to the support in the choice of the suitable countermeasures is highlighted
The paper synthetically deals with the procedures frequently used to assess the opening convergen... more The paper synthetically deals with the procedures frequently used to assess the opening convergence, to design the temporary lining, to evaluate the stress and displacement that are characteristics of the achieved equilibrium state. The stiffness of the lining, in its actual shape and not with the usual closed ring modeling, is evaluated; settling lining supports are taken into account as well as differentiated and evolving stresses in the bolts. The results obtained by an extensive parametric study allow the pointing out of some remarks and comparisons
The paper discusses the use of the formulae of the theory of elasticity to compute the settlement... more The paper discusses the use of the formulae of the theory of elasticity to compute the settlement of shallow foundations in sands when subjected to static loading. Special emphasis is put on the selection of the operational drained Young modulus to be introduced in these formulae, basing on the results of three types of in-situ tests, namely SPT, CPT and DMT. The problem of the 'depth of influence' within which the settlements of footings resting on cohesionless soils should be computed, is also examined.
A new traveling sand pluviator to reconstitute small specimens for laboratory tests was developed... more A new traveling sand pluviator to reconstitute small specimens for laboratory tests was developed in joint research between the Research Center of the Italian National Electricity Board (ENEL CRIS) of Milano and the Department of Structural Engineering of the Politecnico di Torino. The pluviator proved satisfactory in reconstituting small-size specimens because it provided a very high degree of spatial uniformity of density and grain-size distribution. Furthermore, it was shown that a traveling pluviator is preferable to a stationary one even in reconstituting large-size specimens to achieve a higher degree of spatial uniformity. The above advantages were mainly evident when dealing with well-graded silty sands. A noteworthy feature of the new traveling pluviator that sets it apart from existing ones is its ability to accommodate pluviation under evacuated conditions.
The protection of cultural heritage from water-soil interaction related threats is a crucial chal... more The protection of cultural heritage from water-soil interaction related threats is a crucial challenge for the scientific community. Among the hazards threatening heritage buildings, slow-moving landslides have been recently found to produce significant damage to historic masonry churches.
However, assessing the effects of these phenomena is very challenging, as detailed information about slow-moving landslide movements is not generally available. To tackle this problem, geotechnical analyses can be performed, which enable the landslide-induced soil displacement profiles to be predicted. In view of this, this paper investigates the effects of slow-moving landslides on historic masonry churches by performing geotechnical analyses on two case studies located in the Liguria region (Italy). For each case study, limit equilibrium (LE) and finite element (FE) analyses
were carried out with reference to representative sections of the slope on which the building was located. Different scenarios of water table levels were also simulated to evaluate a potential evolution of the slope stability conditions towards failure. Finally, the damage level of the building under study was assessed through a damage criterion available in the literature and compared with the severity of the damage observed on site.
The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical ... more The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical properties and, consequently, to improve the footing load carrying capacity reducing the associated settlements. Simplified approaches generally rely on corrective factors, allowing the analysis of reinforced foundation starting from the knowledge of the performance of the unreinforced one. A critical aspect refers to the applied load: for footings subjected to inclined loads, it is not possible to assess the bearing capacity and the displacements by using simplified methods referred to vertical loading conditions. The paper reports the results of numerical FEM analyses, aimed to investigate the limit conditions for a shallow strip footing subjected to inclined load and to highlight how the failure envelope (in the plane of vertical V and horizontal H load components) of the reinforced foundation modifies (in size and shape) in comparison with that of the unreinforced one. The use of the failure envelope approach, instead of the usual bearing capacity corrective factors, allows a more rational analysis of the interaction phenomena occurring in the reinforced soil. The numerical analyses enable to consider different cases as to the reinforcement arrangements and types
In the paper a new approach, based on the idea above indicated and on the elastic solution by Ran... more In the paper a new approach, based on the idea above indicated and on the elastic solution by Randolph and Wroth (1978), is proposed. The main difference is that non-linearity is taken into account not resorting to a backcalculated \u201coperational stiffness\u201d but directly using a \u201ctypical\u201d shear stiffness degradation curve, deduced from laboratory tests, and introducing \u201cpseudostrain\u201d values to be used in accordance to the decay curve. The "pseudo- strain\u201d is evaluated according to field performance: so it is possible to pass from a laboratory modulus non-linearity to a field modulus non-linearity. The assumed \u201cpseudo strain\u201d is directly the ratio between the settlement w (at the head of the pile) and the diameter D (i.e. the relative settlement) or a shear strain g, function of the pile settlement. Starting from the knowledge of the soil initial stiffness and pile characteristics, a complete non-linear load settlement curve can be evalu...
Italian Geotechnical Journal (Rivista Italiana di Geotecnica), 1998
The present paper reports the analyses performed to investigate the influence of factors such as ... more The present paper reports the analyses performed to investigate the influence of factors such as the rock mass quality and the in situ stress state on the deformational behaviour of rock masses. New correlations among the deformability modulus, the RMR index and the modulus ratio have been obtained from the analysis of a great number of case records. The comparison of these correlations with others, already established, allows useful considerations concerning the use of empirical approaches. Finally, the influence of the confining stress state on the rock mass deformability has been proved and assessed. Il presente articolo riporta le analisi svolte al fine di valutare l\u2019influenza che fattori quali la qualit\ue0 dell\u2019ammasso roccioso e lo stato di sforzo in sito hanno sul comportamento deformativo dell\u2019ammasso stesso. L\u2019elaborazione e l\u2019interpretazione di numerosi dati ricavati dalla letteratura, relativi alle propriet\ue0 di ammassi rocciosi in cui sono state realizzate opere di ingegneria, ha consentito di ottenere nuove correlazioni tra il valore del modulo di deformabilit\ue0 dell\u2019ammasso roccioso, l\u2019indice RMR e il Rapporto di Modulo del materiale roccioso. Esse sono state confrontate con analoghe correlazioni gi\ue0 ben consolidate e di pratico utilizzo, pervenendo a utili considerazioni sull\u2019applicabilit\ue0 delle relazioni empiriche. \uc8 stato possibile accertare infine, qualitativamente e quantitativamente, l\u2019influenza esercitata dall\u2019azione di confinamento dovuta allo stato di sforzo in sito sul modulo di deformabilit\ue0 dell\u2019ammasso roccioso
Proceedings of the Institution of Civil Engineers, 2005
Understanding the principal features of soil stiffness has been one of the major achievements of ... more Understanding the principal features of soil stiffness has been one of the major achievements of geotechnical engineering over the past 30 years. The study of modulus degradation is now one of the main research areas. Understanding non-linearity is essential in foundation design for accurate and reliable evaluation of ground movements. This paper looks at the problem of assessing of deep foundation settlements and describes two approaches developed to enable designers to take soil–foundation non-linear behaviour into account. The first provides in-field stiffness parameters evaluated by back-analysis of full-scale piles. The second involves deducting the behaviour of the soil interacting with a foundation from degradation curves characterising the soil stiffness.
... p. 149-157. Authors: Berardi, R. LANCELLOTTA, R. Publication Date: 1991. Serial: ... Geotechn... more ... p. 149-157. Authors: Berardi, R. LANCELLOTTA, R. Publication Date: 1991. Serial: ... Geotechnology; Highways. Last Modified: Mar 31 1992 12:00AM. More Articles from this Serial Issue: EFFECTS OF DRYING ON THE ENGINEERING BEHAVIOUR OF COCHIN MARINE CLAYS. ...
The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical ... more The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical properties and, consequently, to improve the footing load carrying capacity reducing the associated settlements. Simplified approaches generally rely on corrective factors, allowing the analysis of reinforced foundation starting from the knowledge of the performance of the unreinforced one. A critical aspect refers to the applied load: for footings subjected to inclined loads, it is not possible to assess the bearing capacity and the displacements by using simplified methods referred to vertical loading conditions. The paper reports the results of numerical FEM analyses, aimed to investigate the limit conditions for a shallow strip footing subjected to inclined load and to highlight how the failure envelope (in the plane of vertical V and horizontal H load components) of the reinforced foundation modifies (in size and shape) in comparison with that of the unreinforced one. The use of the failure envelope approach, instead of the usual bearing capacity corrective factors, allows a more rational analysis of the interaction phenomena occurring in the reinforced soil. The numerical analyses enable to consider different cases as to the reinforcement arrangements and types
Innovative researches developed by the Authors are described in order to demonstrate the usefulne... more Innovative researches developed by the Authors are described in order to demonstrate the usefulness of GIS (Geographic Information System) in support of geotechnical analysis, with particular reference to risk zoning and mitigation and to the monitoring of slopes. A multivariate statistical procedure for the estimation of landslide susceptibility, an automatic procedure providing maps of the countermeasures to recommend for slope stabilization and reinforcement, and a cognitive/predictive hydrological-geotechnical (IHG) model coupled with a dense, low-cost network of sensors are presented. The contribution of GIS environment to the analysis and prevention of landslide susceptibility, both at wide area and at local scale, as well as to the support in the choice of the suitable countermeasures is highlighted
The paper synthetically deals with the procedures frequently used to assess the opening convergen... more The paper synthetically deals with the procedures frequently used to assess the opening convergence, to design the temporary lining, to evaluate the stress and displacement that are characteristics of the achieved equilibrium state. The stiffness of the lining, in its actual shape and not with the usual closed ring modeling, is evaluated; settling lining supports are taken into account as well as differentiated and evolving stresses in the bolts. The results obtained by an extensive parametric study allow the pointing out of some remarks and comparisons
The paper discusses the use of the formulae of the theory of elasticity to compute the settlement... more The paper discusses the use of the formulae of the theory of elasticity to compute the settlement of shallow foundations in sands when subjected to static loading. Special emphasis is put on the selection of the operational drained Young modulus to be introduced in these formulae, basing on the results of three types of in-situ tests, namely SPT, CPT and DMT. The problem of the 'depth of influence' within which the settlements of footings resting on cohesionless soils should be computed, is also examined.
A new traveling sand pluviator to reconstitute small specimens for laboratory tests was developed... more A new traveling sand pluviator to reconstitute small specimens for laboratory tests was developed in joint research between the Research Center of the Italian National Electricity Board (ENEL CRIS) of Milano and the Department of Structural Engineering of the Politecnico di Torino. The pluviator proved satisfactory in reconstituting small-size specimens because it provided a very high degree of spatial uniformity of density and grain-size distribution. Furthermore, it was shown that a traveling pluviator is preferable to a stationary one even in reconstituting large-size specimens to achieve a higher degree of spatial uniformity. The above advantages were mainly evident when dealing with well-graded silty sands. A noteworthy feature of the new traveling pluviator that sets it apart from existing ones is its ability to accommodate pluviation under evacuated conditions.
The protection of cultural heritage from water-soil interaction related threats is a crucial chal... more The protection of cultural heritage from water-soil interaction related threats is a crucial challenge for the scientific community. Among the hazards threatening heritage buildings, slow-moving landslides have been recently found to produce significant damage to historic masonry churches.
However, assessing the effects of these phenomena is very challenging, as detailed information about slow-moving landslide movements is not generally available. To tackle this problem, geotechnical analyses can be performed, which enable the landslide-induced soil displacement profiles to be predicted. In view of this, this paper investigates the effects of slow-moving landslides on historic masonry churches by performing geotechnical analyses on two case studies located in the Liguria region (Italy). For each case study, limit equilibrium (LE) and finite element (FE) analyses
were carried out with reference to representative sections of the slope on which the building was located. Different scenarios of water table levels were also simulated to evaluate a potential evolution of the slope stability conditions towards failure. Finally, the damage level of the building under study was assessed through a damage criterion available in the literature and compared with the severity of the damage observed on site.
The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical ... more The use of geo-reinforcements under shallow foundations is aimed to increase the soil mechanical properties and, consequently, to improve the footing load carrying capacity reducing the associated settlements. Simplified approaches generally rely on corrective factors, allowing the analysis of reinforced foundation starting from the knowledge of the performance of the unreinforced one. A critical aspect refers to the applied load: for footings subjected to inclined loads, it is not possible to assess the bearing capacity and the displacements by using simplified methods referred to vertical loading conditions. The paper reports the results of numerical FEM analyses, aimed to investigate the limit conditions for a shallow strip footing subjected to inclined load and to highlight how the failure envelope (in the plane of vertical V and horizontal H load components) of the reinforced foundation modifies (in size and shape) in comparison with that of the unreinforced one. The use of the failure envelope approach, instead of the usual bearing capacity corrective factors, allows a more rational analysis of the interaction phenomena occurring in the reinforced soil. The numerical analyses enable to consider different cases as to the reinforcement arrangements and types
In the paper a new approach, based on the idea above indicated and on the elastic solution by Ran... more In the paper a new approach, based on the idea above indicated and on the elastic solution by Randolph and Wroth (1978), is proposed. The main difference is that non-linearity is taken into account not resorting to a backcalculated \u201coperational stiffness\u201d but directly using a \u201ctypical\u201d shear stiffness degradation curve, deduced from laboratory tests, and introducing \u201cpseudostrain\u201d values to be used in accordance to the decay curve. The "pseudo- strain\u201d is evaluated according to field performance: so it is possible to pass from a laboratory modulus non-linearity to a field modulus non-linearity. The assumed \u201cpseudo strain\u201d is directly the ratio between the settlement w (at the head of the pile) and the diameter D (i.e. the relative settlement) or a shear strain g, function of the pile settlement. Starting from the knowledge of the soil initial stiffness and pile characteristics, a complete non-linear load settlement curve can be evalu...
Uploads
Papers by Riccardo Berardi
However, assessing the effects of these phenomena is very challenging, as detailed information about slow-moving landslide movements is not generally available. To tackle this problem, geotechnical analyses can be performed, which enable the landslide-induced soil displacement profiles to be predicted. In view of this, this paper investigates the effects of slow-moving landslides on historic masonry churches by performing geotechnical analyses on two case studies located in the Liguria region (Italy). For each case study, limit equilibrium (LE) and finite element (FE) analyses
were carried out with reference to representative sections of the slope on which the building was located. Different scenarios of water table levels were also simulated to evaluate a potential evolution of the slope stability conditions towards failure. Finally, the damage level of the building under study was assessed through a damage criterion available in the literature and compared with the severity of the damage observed on site.
However, assessing the effects of these phenomena is very challenging, as detailed information about slow-moving landslide movements is not generally available. To tackle this problem, geotechnical analyses can be performed, which enable the landslide-induced soil displacement profiles to be predicted. In view of this, this paper investigates the effects of slow-moving landslides on historic masonry churches by performing geotechnical analyses on two case studies located in the Liguria region (Italy). For each case study, limit equilibrium (LE) and finite element (FE) analyses
were carried out with reference to representative sections of the slope on which the building was located. Different scenarios of water table levels were also simulated to evaluate a potential evolution of the slope stability conditions towards failure. Finally, the damage level of the building under study was assessed through a damage criterion available in the literature and compared with the severity of the damage observed on site.