Nowadays several reinforced earth typologies are available. One of the most interesting is the ve... more Nowadays several reinforced earth typologies are available. One of the most interesting is the vertical earth walls reinforced with polymeric geostrips with concrete facing panels. Geostrips tensile stiffness is much larger than that of typical geosynthetic sheets. Uncertainties may arise about the real geostrips behaviour: if they should be considered as inextensible or extensible. The aim of this work is giving a contribution to better understand the real behaviour of such polymeric geostrips. An experimental full-scale model of reinforced soil wall was built applying the quoted technology. The experimental model was fully instrumented to measure both stress and deformations on strips and to investigate about earth pressure. The Authors carried out a two-dimensional (2D) FEM analysis to simulate the wall performance. Experimental, numerical and analytical results have been compared in static condition, in order to detect the main aspects of the behaviour of soil walls reinforced w...
Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. ... more Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. Il metodo prevede la raccolta di dati attraverso l"utilizzo di una scheda appositamente realizzata che consente l"acquisizione di informazioni utili per la stima della pericolosità geotecnica-sismica e della vulnerabilità di edifici ed infrastrutture. Viene così determinato un indice di pericolosità geotecnica (IPG) utilizzando una scheda di penalità e vengono individuati i livelli di vulnerabilità degli edifici e delle infrastrutture nelle aree urbane. È stato realizzato un geodatabase, implementato con tecniche GIS, che tiene conto di tutti i parametri necessari per la valutazione del rischio sismico. Il metodo è stato applicato alla città di Siracusa. La classe di pericolosità è stata stimata in base alle proprietà geotecniche dei terreni, dedotte raccogliendo dati provenienti da prove in situ e di laboratorio svolte precedentemente per altri scopi. Con i dati raccolti è stato valutato l"IPG. Il grado di vulnerabilità è stato valutato, per ciascuno degli edifici oggetto di sopralluogo, osservando il tipo di struttura, la relativa funzione ed il livello di danno osservato. Parole chiave: vulnerabilità sismica, data base management system, tecniche GIS, geodatabase, Sicilia orientale.
WIT Transactions on State of the Art in Science and Engineering, 2014
The behaviour of deep foundation under static loads has been widely investigated and the availabl... more The behaviour of deep foundation under static loads has been widely investigated and the available calculation procedures can be considered suitable for the current engineering applications. However, pile behaviour under seismic loading is more complex and less known, because it involves the simultaneous action of inertial forces arising from the superstructure (inertial interaction) and of the soil deformations arising from the seismic waves (kinematic interaction). Italian code DM 14/01/2008 requires the dynamic soil-structure interaction in seismic foundation design to be taken into account, but it does not give any information about criteria for the evaluation of kinematic interaction strains. Experimental evidence and theoretical considerations by many authors show that the kinematic interaction alone may induce high stresses in piles, especially near an interface between a soft and a rigid soil layer. In this work pile behaviour due to kinematic interaction with soil will be examined. An approach based on a differential equation proposed in the relevant technical literature will be used. The analysis is focused on the response of a single pile in a heterogeneous three-layer soil profile.
In Italy, many urban areas suffer geotechnical hazard problems. However the Municipalities are no... more In Italy, many urban areas suffer geotechnical hazard problems. However the Municipalities are not yet organised either to deal with the consequences of the possible phenomena, or to plan risk factor mitigation actions, by vulnerability reduction of the exposed elements.
Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. ... more Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. Il metodo prevede la raccolta di dati attraverso l"utilizzo di una scheda appositamente realizzata che consente l"acquisizione di informazioni utili per la stima della pericolosità geotecnica-sismica e della vulnerabilità di edifici ed infrastrutture. Viene così determinato un indice di pericolosità geotecnica (IPG) utilizzando una scheda di penalità e vengono individuati i livelli di vulnerabilità degli edifici e delle infrastrutture nelle aree urbane. È stato realizzato un geodatabase, implementato con tecniche GIS, che tiene conto di tutti i parametri necessari per la valutazione del rischio sismico. Il metodo è stato applicato alla città di Siracusa. La classe di pericolosità è stata stimata in base alle proprietà geotecniche dei terreni, dedotte raccogliendo dati provenienti da prove in situ e di laboratorio svolte precedentemente per altri scopi. Con i dati raccolti è stato valutato l"IPG. Il grado di vulnerabilità è stato valutato, per ciascuno degli edifici oggetto di sopralluogo, osservando il tipo di struttura, la relativa funzione ed il livello di danno osservato.
The behaviour of deep foundation under static loads has been widely investigated and the availabl... more The behaviour of deep foundation under static loads has been widely investigated and the available calculation procedures can be considered suitable for the current engineering applications. However, pile behaviour under seismic loading is more complex and less known, because one can find the contemporary action of inertial forces rising from the over-structure (inertial interaction) and of the soil deformations rising from the seismic waves (kinematic interaction). Italian code DM 14/01/2008 requires the dynamic soil-structure interaction in seismic foundation design to be taken into account, but it does not give any information about kinematic interaction strains evaluation criteria. Experimental evidences and theoretical considerations of many authors show that simply the kinematic interaction may induce high stresses on piles, especially near an alternation between a soft and a rigid soil layer interface. In this work pile behaviour due to kinematic interaction will be examined. An approach based on the differential equation proposed by Kavvadas and Gazetas (Kinematic seismic response and bending of free-head piles in layered soil. Géotechnique, 43, N.2, 207-222, 1993) will be used. The analysis is focused on the response of a single pile in a heterogeneous three-layer soil profile.
In every urbanized area, lifelines and essential facilities play a very important role and they b... more In every urbanized area, lifelines and essential facilities play a very important role and they become essential after natural disasters, such as earthquakes, floods, landslides and so on. The purpose of this research is to develop a working tool to assess lifeline seismic risk, overlaying information about the studied area's seismic hazard (referring to a seismic scenario) and lifelines that could expect damage. In damage models parameters are required, some representing pipes, others representing the soil behaviour and finally, at the very least a synthetic parameter representing the seismic hazard of the studied area (PGA, PGV or PGD). The evaluation of the network intrinsic vulnerability will be done in terms of a synthetic parameter called the Repair Rate. PGDs will be evaluated referring to attenuation laws and to earthquake induced slope displacements according to the Newmark approach. An application of the proposed model, developed by GIS techniques, will be applied to the case of a Sicily (Italy) important water network.
Shallow slopes in clayey colluvial covers are often involved in progressive downhill motion with ... more Shallow slopes in clayey colluvial covers are often involved in progressive downhill motion with discontinuous rate of movements, depending on fluctuations in pore-water pressure.
Nowadays several reinforced earth typologies are available. One of the most interesting is the ve... more Nowadays several reinforced earth typologies are available. One of the most interesting is the vertical earth walls reinforced with polymeric geostrips with concrete facing panels. Geostrips tensile stiffness is much larger than that of typical geosynthetic sheets. Uncertainties may arise about the real geostrips behaviour: if they should be considered as inextensible or extensible. The aim of this work is giving a contribution to better understand the real behaviour of such polymeric geostrips. An experimental full-scale model of reinforced soil wall was built applying the quoted technology. The experimental model was fully instrumented to measure both stress and deformations on strips and to investigate about earth pressure. The Authors carried out a two-dimensional (2D) FEM analysis to simulate the wall performance. Experimental, numerical and analytical results have been compared in static condition, in order to detect the main aspects of the behaviour of soil walls reinforced w...
Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. ... more Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. Il metodo prevede la raccolta di dati attraverso l"utilizzo di una scheda appositamente realizzata che consente l"acquisizione di informazioni utili per la stima della pericolosità geotecnica-sismica e della vulnerabilità di edifici ed infrastrutture. Viene così determinato un indice di pericolosità geotecnica (IPG) utilizzando una scheda di penalità e vengono individuati i livelli di vulnerabilità degli edifici e delle infrastrutture nelle aree urbane. È stato realizzato un geodatabase, implementato con tecniche GIS, che tiene conto di tutti i parametri necessari per la valutazione del rischio sismico. Il metodo è stato applicato alla città di Siracusa. La classe di pericolosità è stata stimata in base alle proprietà geotecniche dei terreni, dedotte raccogliendo dati provenienti da prove in situ e di laboratorio svolte precedentemente per altri scopi. Con i dati raccolti è stato valutato l"IPG. Il grado di vulnerabilità è stato valutato, per ciascuno degli edifici oggetto di sopralluogo, osservando il tipo di struttura, la relativa funzione ed il livello di danno osservato. Parole chiave: vulnerabilità sismica, data base management system, tecniche GIS, geodatabase, Sicilia orientale.
WIT Transactions on State of the Art in Science and Engineering, 2014
The behaviour of deep foundation under static loads has been widely investigated and the availabl... more The behaviour of deep foundation under static loads has been widely investigated and the available calculation procedures can be considered suitable for the current engineering applications. However, pile behaviour under seismic loading is more complex and less known, because it involves the simultaneous action of inertial forces arising from the superstructure (inertial interaction) and of the soil deformations arising from the seismic waves (kinematic interaction). Italian code DM 14/01/2008 requires the dynamic soil-structure interaction in seismic foundation design to be taken into account, but it does not give any information about criteria for the evaluation of kinematic interaction strains. Experimental evidence and theoretical considerations by many authors show that the kinematic interaction alone may induce high stresses in piles, especially near an interface between a soft and a rigid soil layer. In this work pile behaviour due to kinematic interaction with soil will be examined. An approach based on a differential equation proposed in the relevant technical literature will be used. The analysis is focused on the response of a single pile in a heterogeneous three-layer soil profile.
In Italy, many urban areas suffer geotechnical hazard problems. However the Municipalities are no... more In Italy, many urban areas suffer geotechnical hazard problems. However the Municipalities are not yet organised either to deal with the consequences of the possible phenomena, or to plan risk factor mitigation actions, by vulnerability reduction of the exposed elements.
Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. ... more Viene presentato un approccio per la produzione di mappe di rischio sismico di aree urbanizzate. Il metodo prevede la raccolta di dati attraverso l"utilizzo di una scheda appositamente realizzata che consente l"acquisizione di informazioni utili per la stima della pericolosità geotecnica-sismica e della vulnerabilità di edifici ed infrastrutture. Viene così determinato un indice di pericolosità geotecnica (IPG) utilizzando una scheda di penalità e vengono individuati i livelli di vulnerabilità degli edifici e delle infrastrutture nelle aree urbane. È stato realizzato un geodatabase, implementato con tecniche GIS, che tiene conto di tutti i parametri necessari per la valutazione del rischio sismico. Il metodo è stato applicato alla città di Siracusa. La classe di pericolosità è stata stimata in base alle proprietà geotecniche dei terreni, dedotte raccogliendo dati provenienti da prove in situ e di laboratorio svolte precedentemente per altri scopi. Con i dati raccolti è stato valutato l"IPG. Il grado di vulnerabilità è stato valutato, per ciascuno degli edifici oggetto di sopralluogo, osservando il tipo di struttura, la relativa funzione ed il livello di danno osservato.
The behaviour of deep foundation under static loads has been widely investigated and the availabl... more The behaviour of deep foundation under static loads has been widely investigated and the available calculation procedures can be considered suitable for the current engineering applications. However, pile behaviour under seismic loading is more complex and less known, because one can find the contemporary action of inertial forces rising from the over-structure (inertial interaction) and of the soil deformations rising from the seismic waves (kinematic interaction). Italian code DM 14/01/2008 requires the dynamic soil-structure interaction in seismic foundation design to be taken into account, but it does not give any information about kinematic interaction strains evaluation criteria. Experimental evidences and theoretical considerations of many authors show that simply the kinematic interaction may induce high stresses on piles, especially near an alternation between a soft and a rigid soil layer interface. In this work pile behaviour due to kinematic interaction will be examined. An approach based on the differential equation proposed by Kavvadas and Gazetas (Kinematic seismic response and bending of free-head piles in layered soil. Géotechnique, 43, N.2, 207-222, 1993) will be used. The analysis is focused on the response of a single pile in a heterogeneous three-layer soil profile.
In every urbanized area, lifelines and essential facilities play a very important role and they b... more In every urbanized area, lifelines and essential facilities play a very important role and they become essential after natural disasters, such as earthquakes, floods, landslides and so on. The purpose of this research is to develop a working tool to assess lifeline seismic risk, overlaying information about the studied area's seismic hazard (referring to a seismic scenario) and lifelines that could expect damage. In damage models parameters are required, some representing pipes, others representing the soil behaviour and finally, at the very least a synthetic parameter representing the seismic hazard of the studied area (PGA, PGV or PGD). The evaluation of the network intrinsic vulnerability will be done in terms of a synthetic parameter called the Repair Rate. PGDs will be evaluated referring to attenuation laws and to earthquake induced slope displacements according to the Newmark approach. An application of the proposed model, developed by GIS techniques, will be applied to the case of a Sicily (Italy) important water network.
Shallow slopes in clayey colluvial covers are often involved in progressive downhill motion with ... more Shallow slopes in clayey colluvial covers are often involved in progressive downhill motion with discontinuous rate of movements, depending on fluctuations in pore-water pressure.
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Papers by Erminia Raciti