The greatest cities in human history have risen up on the banks of rivers and by the seaside. In ... more The greatest cities in human history have risen up on the banks of rivers and by the seaside. In fact, living by the water provides with a number of advantages and assets such as fertile farm land, transportation, trade and hydroelectric power. On the other hand, in doing so, people chose to live in close confines with an unruly force and, unfortunately, often they forget it. A levee is a man-made embankment built to contain and control the flow of water (of a river) so as to provide protection against floods or to prevent ocean waves from washing into undesired areas. In parts of the Netherlands, for example, levees stop ocean waters from reclaiming thousands of miles of land (much of which is either at or below sea level). Often levees are little more than trapezoidal mounds of less permeable soil (clay) which run in a long strip for many kilometers along a river (or a lake or ocean). Often levees are in urgent need of repair. The problems are several: poor maintenance; design and...
In questo lavoro sono stati descritti i vantaggi e i campi di applicazione della tecnica del rici... more In questo lavoro sono stati descritti i vantaggi e i campi di applicazione della tecnica del riciclaggio a freddo, focalizzando l’attenzione e confrontando i due tipi di leganti impiegati per la stabilizzazione degli inerti di recupero, cioè: l’emulsione polimerica e il bitume schiumato. Successivamente si è proceduto allo studio della tecnica di riciclaggio a freddo con il bitume schiumato che rappresenta il tema di questo studio. Si sono descritti i parametri che permettono di valutare le caratteristiche schiumogene di un bitume: il tempo di dimezzamento, il rapporto di espansione e l’indice di schiuma e le diverse modalità con cui si può manifestare il decadimento della schiuma prodotta da un bitume semisolido. Sono stati esaminati i fattori che influenzano la produzione di una miscela di schiumato di adeguate caratteristiche: il tipo di bitume semisolido, il suo contenuto ottimo e la sua temperatura, il contenuto ottimo di acqua, il tipo di aggregati (granulometria e plasticità)...
The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers a... more The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers above the water table and loose, intermediate - permeability soils (loose silt mixtures). The paper shows an approach that could be used for the first type of soil to infer the effective vertical stress from CPTu measurements and in particular from the Ic index. The approach has been checked on a very limited amount of experimental evidence. Moreover, an empirical correction of the Ic index is provided in order to obtain a more realistic soil profiling of loose silt mixtures. The foundation soils of the Serchio River levee system and some dredged sediments, which had been stored in the Port of Livorno, have been considered for the second type of soil.
In this study, a bamboo species, the Phyllostachys pubescens – Moso Bamboo (MB) -, was selected f... more In this study, a bamboo species, the Phyllostachys pubescens – Moso Bamboo (MB) -, was selected for its heavy metals accumulation and translocation potential to restore Cr-contaminated soil. In order to evaluate the potential for phytoremediation using MB to restore Cr-contaminated soil, pot experiments were carried out in simulated Mediterranean conditions, in laboratory, in a controlled environment, at a temperature of 20°C. Cr removal from soil was 43 % starting from a Cr content of approx. 200 mg/kg Dry Weight and the quantity of Cr per gram of root and rhizome was equal to 1.31 mg/g dw, while the quantity of Cr per gram of stem and leaves was equal to 0.86 mg/g dw, after 12 weeks. Pot experiments confirm that phytoremediation using plants such as MB provides an alternative approach for handling Cr-contaminated soil.
Climatic changes are expected to increase both the frequency and severity of flooding across the ... more Climatic changes are expected to increase both the frequency and severity of flooding across the world. It is not possible to plan a continuous increase of levee height and its geometry. Therefore levees should resist to overtopping. This Technical Note gives an updated review of the surface erosion phenomena that can occur during floods and mainly deals with a case history on the effect of overtopping on a trial embankment in stabilized soil. The possible use of recycled soil is also discussed.
Engineering Geology for Society and Territory - Volume 2, 2015
The paper illustrates an innovative method to evaluate the degree of compaction of both existing ... more The paper illustrates an innovative method to evaluate the degree of compaction of both existing and new river embankments after their completion. A tip resistance target—profile is inferred from laboratory tests in a mini calibration chamber (CC) using a mini CPT (cone penetration test). The “laboratory” tip resistance (qcLAB) is expressed as a function of the expected density and of the vertical—horizontal stress components. Such a dependence of qcLAB is obtained carrying out a number of repeated tests in the CC at given density and different consolidation stresses. In situ stresses are inferred by combining DMT (Marchetti Dilatomer) results and an estimate of the vertical stress component. A comparison between the qcLAB profile, from CC testing, and the qc, as inferred from in situ CPT, gives the possibility of assessing the density of existing embankments, while, for new embankments, the method defines the expected in situ qc for a given target density.
L'obiettivo dello studio è la messa a punto di un metodo per il controllo del grado di co... more L'obiettivo dello studio è la messa a punto di un metodo per il controllo del grado di compattazione e/o delle caratteristiche prestazionali di rilevati (manufatti) in terreni a grana fine. La metodologia proposta è da tempo oggetto di studio presso l'Unità di Ricerca di Pisa ed il presente lavoro illustra lo stato di avanzamento del progetto. Il metodo prevede l'utilizzo di prove in sito e prove di laboratorio. In particolare le prove CPT E in laboratorio, in scala ridotta, in una mini-camera di calibrazione vengono utilizzate per definire un profilo penetrometrico di riferimento; le prove CPT E e DMT in sito servono rispettivamente a verificare che il manufatto, oggetto del controllo, esibisca un profilo penetrometrico non peggiore di quello di riferimento e a determinare lo stato tensionale in sito. L'aspetto di maggior difficoltà, riguardante la metodologia proposta, consiste nella valutazione dello stato tensionale (in sito e in laboratorio) e dei fattori che influenzano la resistenza penetrometrica (in sito e in laboratorio) nel caso di un manufatto di terre a grana fine parzialmente sature e compattate meccanicamente. Le prove penetrometriche in laboratorio, in scala ridotta, sono state eseguite in una camera di calibrazione (diametro 320 mm) sviluppata e modificata presso il Laboratorio Geotecnico dell'Università di Pisa con il supporto della Pagani Geotechnical Equipment, utilizzando un mini-penetrometro avente caratteristiche simili a quello in scala reale ed un diametro di 8 mm. La camera di calibrazione ha contorni flessibili lateralmente e inferiormente e contorno rigido all'estremità superiore. Le prove in camera di calibrazione sono state eseguite su campioni di una sabbia di frantoio in condizioni asciutte e su un limo sabbioso – argilloso addensato con un contenuto d'acqua pari a circa il 13%. Tutte le prove sono state eseguite con tensioni al contorno costanti (BC1). La presente nota si concentra sull'influenza delle tensioni al contorno sulla resistenza penetrometrica. Si propone inoltre, in via preliminare, una possibile correlazione tra la resistenza alla punta ed il modulo dinamico misurato con prove LWD.
This paper deals with the geotechnical design of levees in flood plain areas. As far as this type... more This paper deals with the geotechnical design of levees in flood plain areas. As far as this type of river embankment is concerned, the main potential failure mechanisms can be summarised as follows: – various types of internal erosion phenomena; – external erosion due to overtopping; – slope instability; – hydraulic heave/uplift; – excessive settlements The durability of a river embankment mainly depends on its capability to: – survive after the occurrence of overtopping phenomena; – experience, during its life, limited settlements in order to avoid the need of continuous refurbishments for the maintenance of the Serviceability Limit State (SLS) – avoid the occurrence of excessive settlements that could lead the structure to its Ultimate Limit State (ULS); – avoid the occurrence and propagation of internal erosion phenomena; – resist to mechanical/hydraulic actions even under to fully saturated condition. Some of the above mentioned aspects could be studied throughout an appropriat...
The floodplain embankments of the Serchio River (Tuscany, Italy) have experienced several failure... more The floodplain embankments of the Serchio River (Tuscany, Italy) have experienced several failures during their life. After the event of December 2009 a detailed geotechnical investigation has been carried out. This paper discusses the necessary criteria for a cost-effective investigation taking into account the total length of the embankments (30 km), the requested level of detail and analyses and the capability of indirect methods (CPTu, 2D geo-electric tomography) to infer the soil stratigraphy. In this respect, it has been confirmed that CPTu test is an expeditious, economical and effective indirect method for soil profiling, if the results are correctly calibrated against borehole-logs. On the other hand, geo-electric investigations can be very useful to highlight anomalies and hetero-geneities in the embankment cross section. Following the geotechnical characterization of the Serchio River a number of analyses have been carried out for various purposes: to clarify the causes of the December 2009 failures, to design appropriate repair of the failures and retrofit of the embankments in proximity of the failures and to identify the risk areas considering the whole extension of the embankments. The following Ultimate Limit States have been considered: Slope failure and hydraulic heave (under steady state flow conditions) by the Limit Equilibrium Method. The stability analyses have been carried out using the Bishop simplified method with circular sliding surfaces and using three different commercial codes. Safety factor against hydraulic heave has been computed according to NTC 2008. Slope failure under transient flow conditions by means of FEM analysis (PLAXIS Flow), in order to assess the time to approach the steady state flow conditions. FEM analysis also considered the stability in the case of partial saturation since the water table is usually few meters below the embankment base. Susceptibility of the embankment and foundation soil to internal erosion phenomena. The paper also tries to clarify the redundant terminology that is used to describe the same phenomenon and, at the same time, points out the need to use appropriate terminology to describe different phenomena related to internal erosion. Appropriate design of both repair of the failures and retrofitting of the surrounding areas has been achieved on the basis of the above analyses. Assessment of the riskiest areas, considering the whole extension of the embankments, has been carried out by means of expeditious criteria, which were based on the embankment geometry and the mechanical soil characteristics. The analysis results show that, for the selected cross sections, the safety factors are rather small and approaching to unit if the seepage forces are not considered. In the case of steady state flow, safety factor drastically reduces to values lower than one. The results of the FEM analyses suggest that the partial saturation of the embankment-material mainly contributes to its stability in the absence of filtration, leading to acceptable safety margins. A good characterization of the material under conditions of partial saturation would allow applying the most appropriate hydraulic conditions.
The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers a... more The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers above the water table and loose, intermediate - permeability soils (loose silt mixtures). The paper shows an approach that could be used for the first type of soil to infer the effective vertical stress from CPTu measurements and in particular from the Ic index. The approach has been checked on a very limited amount of experimental evidence. Moreover, an empirical correction of the Ic index is provided in order to obtain a more realistic soil profiling of loose silt mixtures. The foundation soils of the Serchio River levee system and some dredged sediments, which had been stored in the Port of Livorno, have been considered for the second type of soil.
The paper illustrates an innovative method to evaluate the degree of compaction of both existing ... more The paper illustrates an innovative method to evaluate the degree of compaction of both existing and new river embankments after their completion. A tip resistance target - profile is inferred from laboratory tests in a mini calibration chamber (CC) using a mini CPT. The “laboratory” tip resistance (qcLAB) is expressed as a function of the expected density and of the vertical – horizontal stress components. Such a dependence of qcLAB is obtained carrying out a number of repeated tests in the CC at given density and different consolidation stresses. In situ stresses are inferred by combining DMT results and an estimate of the vertical stress component. A comparison between the qcLAB profile, from CC testing, and the qc, as inferred from in situ CPT, gives the possibility of assessing the density of existing embankments, while, for new embankments, the method defines the expected in situ qc for a given target density. This method has been successfully used in some case histories (already published data). The paper, after the description of the method, focuses on the effects of stresses on the tip resistance in the case of dry sand and partially saturated fine soil. Eventually, a correlation is attempted between the tip resistance and the dynamic modulus (Ed) as inferred from LFWD. Indeed LFWD could be a useful and expeditious tool for controlling the degree of compaction during the construction stage.
The greatest cities in human history have risen up on the banks of rivers and by the seaside. In ... more The greatest cities in human history have risen up on the banks of rivers and by the seaside. In fact, living by the water provides with a number of advantages and assets such as fertile farm land, transportation, trade and hydroelectric power. On the other hand, in doing so, people chose to live in close confines with an unruly force and, unfortunately, often they forget it. A levee is a man-made embankment built to contain and control the flow of water (of a river) so as to provide protection against floods or to prevent ocean waves from washing into undesired areas. In parts of the Netherlands, for example, levees stop ocean waters from reclaiming thousands of miles of land (much of which is either at or below sea level). Often levees are little more than trapezoidal mounds of less permeable soil (clay) which run in a long strip for many kilometers along a river (or a lake or ocean). Often levees are in urgent need of repair. The problems are several: poor maintenance; design and...
In questo lavoro sono stati descritti i vantaggi e i campi di applicazione della tecnica del rici... more In questo lavoro sono stati descritti i vantaggi e i campi di applicazione della tecnica del riciclaggio a freddo, focalizzando l’attenzione e confrontando i due tipi di leganti impiegati per la stabilizzazione degli inerti di recupero, cioè: l’emulsione polimerica e il bitume schiumato. Successivamente si è proceduto allo studio della tecnica di riciclaggio a freddo con il bitume schiumato che rappresenta il tema di questo studio. Si sono descritti i parametri che permettono di valutare le caratteristiche schiumogene di un bitume: il tempo di dimezzamento, il rapporto di espansione e l’indice di schiuma e le diverse modalità con cui si può manifestare il decadimento della schiuma prodotta da un bitume semisolido. Sono stati esaminati i fattori che influenzano la produzione di una miscela di schiumato di adeguate caratteristiche: il tipo di bitume semisolido, il suo contenuto ottimo e la sua temperatura, il contenuto ottimo di acqua, il tipo di aggregati (granulometria e plasticità)...
The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers a... more The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers above the water table and loose, intermediate - permeability soils (loose silt mixtures). The paper shows an approach that could be used for the first type of soil to infer the effective vertical stress from CPTu measurements and in particular from the Ic index. The approach has been checked on a very limited amount of experimental evidence. Moreover, an empirical correction of the Ic index is provided in order to obtain a more realistic soil profiling of loose silt mixtures. The foundation soils of the Serchio River levee system and some dredged sediments, which had been stored in the Port of Livorno, have been considered for the second type of soil.
In this study, a bamboo species, the Phyllostachys pubescens – Moso Bamboo (MB) -, was selected f... more In this study, a bamboo species, the Phyllostachys pubescens – Moso Bamboo (MB) -, was selected for its heavy metals accumulation and translocation potential to restore Cr-contaminated soil. In order to evaluate the potential for phytoremediation using MB to restore Cr-contaminated soil, pot experiments were carried out in simulated Mediterranean conditions, in laboratory, in a controlled environment, at a temperature of 20°C. Cr removal from soil was 43 % starting from a Cr content of approx. 200 mg/kg Dry Weight and the quantity of Cr per gram of root and rhizome was equal to 1.31 mg/g dw, while the quantity of Cr per gram of stem and leaves was equal to 0.86 mg/g dw, after 12 weeks. Pot experiments confirm that phytoremediation using plants such as MB provides an alternative approach for handling Cr-contaminated soil.
Climatic changes are expected to increase both the frequency and severity of flooding across the ... more Climatic changes are expected to increase both the frequency and severity of flooding across the world. It is not possible to plan a continuous increase of levee height and its geometry. Therefore levees should resist to overtopping. This Technical Note gives an updated review of the surface erosion phenomena that can occur during floods and mainly deals with a case history on the effect of overtopping on a trial embankment in stabilized soil. The possible use of recycled soil is also discussed.
Engineering Geology for Society and Territory - Volume 2, 2015
The paper illustrates an innovative method to evaluate the degree of compaction of both existing ... more The paper illustrates an innovative method to evaluate the degree of compaction of both existing and new river embankments after their completion. A tip resistance target—profile is inferred from laboratory tests in a mini calibration chamber (CC) using a mini CPT (cone penetration test). The “laboratory” tip resistance (qcLAB) is expressed as a function of the expected density and of the vertical—horizontal stress components. Such a dependence of qcLAB is obtained carrying out a number of repeated tests in the CC at given density and different consolidation stresses. In situ stresses are inferred by combining DMT (Marchetti Dilatomer) results and an estimate of the vertical stress component. A comparison between the qcLAB profile, from CC testing, and the qc, as inferred from in situ CPT, gives the possibility of assessing the density of existing embankments, while, for new embankments, the method defines the expected in situ qc for a given target density.
L'obiettivo dello studio è la messa a punto di un metodo per il controllo del grado di co... more L'obiettivo dello studio è la messa a punto di un metodo per il controllo del grado di compattazione e/o delle caratteristiche prestazionali di rilevati (manufatti) in terreni a grana fine. La metodologia proposta è da tempo oggetto di studio presso l'Unità di Ricerca di Pisa ed il presente lavoro illustra lo stato di avanzamento del progetto. Il metodo prevede l'utilizzo di prove in sito e prove di laboratorio. In particolare le prove CPT E in laboratorio, in scala ridotta, in una mini-camera di calibrazione vengono utilizzate per definire un profilo penetrometrico di riferimento; le prove CPT E e DMT in sito servono rispettivamente a verificare che il manufatto, oggetto del controllo, esibisca un profilo penetrometrico non peggiore di quello di riferimento e a determinare lo stato tensionale in sito. L'aspetto di maggior difficoltà, riguardante la metodologia proposta, consiste nella valutazione dello stato tensionale (in sito e in laboratorio) e dei fattori che influenzano la resistenza penetrometrica (in sito e in laboratorio) nel caso di un manufatto di terre a grana fine parzialmente sature e compattate meccanicamente. Le prove penetrometriche in laboratorio, in scala ridotta, sono state eseguite in una camera di calibrazione (diametro 320 mm) sviluppata e modificata presso il Laboratorio Geotecnico dell'Università di Pisa con il supporto della Pagani Geotechnical Equipment, utilizzando un mini-penetrometro avente caratteristiche simili a quello in scala reale ed un diametro di 8 mm. La camera di calibrazione ha contorni flessibili lateralmente e inferiormente e contorno rigido all'estremità superiore. Le prove in camera di calibrazione sono state eseguite su campioni di una sabbia di frantoio in condizioni asciutte e su un limo sabbioso – argilloso addensato con un contenuto d'acqua pari a circa il 13%. Tutte le prove sono state eseguite con tensioni al contorno costanti (BC1). La presente nota si concentra sull'influenza delle tensioni al contorno sulla resistenza penetrometrica. Si propone inoltre, in via preliminare, una possibile correlazione tra la resistenza alla punta ed il modulo dinamico misurato con prove LWD.
This paper deals with the geotechnical design of levees in flood plain areas. As far as this type... more This paper deals with the geotechnical design of levees in flood plain areas. As far as this type of river embankment is concerned, the main potential failure mechanisms can be summarised as follows: – various types of internal erosion phenomena; – external erosion due to overtopping; – slope instability; – hydraulic heave/uplift; – excessive settlements The durability of a river embankment mainly depends on its capability to: – survive after the occurrence of overtopping phenomena; – experience, during its life, limited settlements in order to avoid the need of continuous refurbishments for the maintenance of the Serviceability Limit State (SLS) – avoid the occurrence of excessive settlements that could lead the structure to its Ultimate Limit State (ULS); – avoid the occurrence and propagation of internal erosion phenomena; – resist to mechanical/hydraulic actions even under to fully saturated condition. Some of the above mentioned aspects could be studied throughout an appropriat...
The floodplain embankments of the Serchio River (Tuscany, Italy) have experienced several failure... more The floodplain embankments of the Serchio River (Tuscany, Italy) have experienced several failures during their life. After the event of December 2009 a detailed geotechnical investigation has been carried out. This paper discusses the necessary criteria for a cost-effective investigation taking into account the total length of the embankments (30 km), the requested level of detail and analyses and the capability of indirect methods (CPTu, 2D geo-electric tomography) to infer the soil stratigraphy. In this respect, it has been confirmed that CPTu test is an expeditious, economical and effective indirect method for soil profiling, if the results are correctly calibrated against borehole-logs. On the other hand, geo-electric investigations can be very useful to highlight anomalies and hetero-geneities in the embankment cross section. Following the geotechnical characterization of the Serchio River a number of analyses have been carried out for various purposes: to clarify the causes of the December 2009 failures, to design appropriate repair of the failures and retrofit of the embankments in proximity of the failures and to identify the risk areas considering the whole extension of the embankments. The following Ultimate Limit States have been considered: Slope failure and hydraulic heave (under steady state flow conditions) by the Limit Equilibrium Method. The stability analyses have been carried out using the Bishop simplified method with circular sliding surfaces and using three different commercial codes. Safety factor against hydraulic heave has been computed according to NTC 2008. Slope failure under transient flow conditions by means of FEM analysis (PLAXIS Flow), in order to assess the time to approach the steady state flow conditions. FEM analysis also considered the stability in the case of partial saturation since the water table is usually few meters below the embankment base. Susceptibility of the embankment and foundation soil to internal erosion phenomena. The paper also tries to clarify the redundant terminology that is used to describe the same phenomenon and, at the same time, points out the need to use appropriate terminology to describe different phenomena related to internal erosion. Appropriate design of both repair of the failures and retrofitting of the surrounding areas has been achieved on the basis of the above analyses. Assessment of the riskiest areas, considering the whole extension of the embankments, has been carried out by means of expeditious criteria, which were based on the embankment geometry and the mechanical soil characteristics. The analysis results show that, for the selected cross sections, the safety factors are rather small and approaching to unit if the seepage forces are not considered. In the case of steady state flow, safety factor drastically reduces to values lower than one. The results of the FEM analyses suggest that the partial saturation of the embankment-material mainly contributes to its stability in the absence of filtration, leading to acceptable safety margins. A good characterization of the material under conditions of partial saturation would allow applying the most appropriate hydraulic conditions.
The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers a... more The paper deals with the interpretation of CPTu in unusual soils, such as shallow clayey layers above the water table and loose, intermediate - permeability soils (loose silt mixtures). The paper shows an approach that could be used for the first type of soil to infer the effective vertical stress from CPTu measurements and in particular from the Ic index. The approach has been checked on a very limited amount of experimental evidence. Moreover, an empirical correction of the Ic index is provided in order to obtain a more realistic soil profiling of loose silt mixtures. The foundation soils of the Serchio River levee system and some dredged sediments, which had been stored in the Port of Livorno, have been considered for the second type of soil.
The paper illustrates an innovative method to evaluate the degree of compaction of both existing ... more The paper illustrates an innovative method to evaluate the degree of compaction of both existing and new river embankments after their completion. A tip resistance target - profile is inferred from laboratory tests in a mini calibration chamber (CC) using a mini CPT. The “laboratory” tip resistance (qcLAB) is expressed as a function of the expected density and of the vertical – horizontal stress components. Such a dependence of qcLAB is obtained carrying out a number of repeated tests in the CC at given density and different consolidation stresses. In situ stresses are inferred by combining DMT results and an estimate of the vertical stress component. A comparison between the qcLAB profile, from CC testing, and the qc, as inferred from in situ CPT, gives the possibility of assessing the density of existing embankments, while, for new embankments, the method defines the expected in situ qc for a given target density. This method has been successfully used in some case histories (already published data). The paper, after the description of the method, focuses on the effects of stresses on the tip resistance in the case of dry sand and partially saturated fine soil. Eventually, a correlation is attempted between the tip resistance and the dynamic modulus (Ed) as inferred from LFWD. Indeed LFWD could be a useful and expeditious tool for controlling the degree of compaction during the construction stage.
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The paper shows an approach that could be used for the first type of soil to infer the effective vertical stress from CPTu measurements and in particular from the Ic index. The approach has been checked on a very limited amount of experimental evidence.
Moreover, an empirical correction of the Ic index is provided in order to obtain a more realistic soil profiling of loose silt mixtures.
The foundation soils of the Serchio River levee system and some dredged sediments, which had been stored in the Port of Livorno, have been considered for the second type of soil.
while, for new embankments, the method defines the expected in situ qc for a given target density. This method has been successfully used in some case histories (already published data). The paper, after the description of the method, focuses on the effects of stresses on the tip resistance in the case of dry sand and partially saturated fine soil. Eventually, a correlation is attempted between the tip resistance and the dynamic modulus (Ed) as inferred from LFWD. Indeed LFWD could be a useful and expeditious tool for controlling the degree of compaction during the construction stage.
The paper shows an approach that could be used for the first type of soil to infer the effective vertical stress from CPTu measurements and in particular from the Ic index. The approach has been checked on a very limited amount of experimental evidence.
Moreover, an empirical correction of the Ic index is provided in order to obtain a more realistic soil profiling of loose silt mixtures.
The foundation soils of the Serchio River levee system and some dredged sediments, which had been stored in the Port of Livorno, have been considered for the second type of soil.
while, for new embankments, the method defines the expected in situ qc for a given target density. This method has been successfully used in some case histories (already published data). The paper, after the description of the method, focuses on the effects of stresses on the tip resistance in the case of dry sand and partially saturated fine soil. Eventually, a correlation is attempted between the tip resistance and the dynamic modulus (Ed) as inferred from LFWD. Indeed LFWD could be a useful and expeditious tool for controlling the degree of compaction during the construction stage.