The three large landslides that occured in Slovenia in past few years and threaten the population... more The three large landslides that occured in Slovenia in past few years and threaten the population and infrastructure were relatively well investigated geologically and geomechanically. One of common characteristics of all three landslides is the occurence of fast debris flows. One part of laboratory investigations was therefore focused into the study of materials that under given circumstances transform into debris flow. In addition to standard geomechanical investigations their behaviour was tested also in rheometer. In the paper the results of all laboratory tests are compared for the mentioned three landslides. The results of rheometer tests showed a consistency between test results and material behaviour on site for two tested materials.
This paper focuses on the design phase of I-BIM tunnelling projects using Sequential Excavation M... more This paper focuses on the design phase of I-BIM tunnelling projects using Sequential Excavation Method (SEM), in Europe, commonly referred to as the New Austrian Tunnelling Method (NATM), and addresses the problem of coupling geotechnical conditions and tunnelling Building Information Model (BIM) for the preparation of the computational model suitable for the finite element analysis method (FEM). The review of the literature led to the conclusion that an automatic merging of the tunnel model and ground model for use in the FEM software is currently not reliable due to the number of differences between various types of models as they serve contrasting needs. Consequently, modelling becomes a manual task, which is very time-consuming and error prone. In this paper, we present the development of a framework for the semiautomatic transformation of the various tunnelling models and respective ground models into the model suitable for further analysis. We conclude that the import and tran...
The development of the Port of Koper started in 1957 in the Gulf of Koper at the northern coast o... more The development of the Port of Koper started in 1957 in the Gulf of Koper at the northern coast of the old town. The first berths constructed on flysch bedrock soon became insufficient for the growing activity of the young port and the development of additional berths had to move to the area where thick deposits of soft marine clay dominated. The paper briefly describes the history of the development of the Port of Koper and presents some selected case histories from its construction.
The proposed manuscript presents an application of neural networks for predicting the displacemen... more The proposed manuscript presents an application of neural networks for predicting the displacement of two landslides, one with maximum displacement rate of a few meters per day and one with a fraction of millimiter per day, using observed rainfall as the only predictor. The issue is relevant because it applies to real-time monitoring of active landslides, with obvious impact on lives and infrastructure, and it is well within the Journal’s aims and scope.
ABSTRACT: In Slovenia first DMT tests were performed in the beginning of 2003. Slovenia is a smal... more ABSTRACT: In Slovenia first DMT tests were performed in the beginning of 2003. Slovenia is a small country, covering only 20 500 km, but with very complex geology. The assessment of ground properties is therefore a demanding task and methods that provide profiles of material properties rather than individual material data are very important. A CPT test with pore pressure measurements has been extensively used in the past. Ménard pressuremeter tests have also been used to complement CPT. Marchetti flat dilatometer tests have proven to be a fast and reliable tool when material properties are required for the assessment of stability and settlements for different geotechnical structures. The paper presents some first comparisons of DMT results with other soil investigation techniques, including laboratory and in situ tests, such as vane test, CPT and Ménard pressuremeter. Measured and predicted settlements are compared at three locations. During the first three years of the use of DMT t...
Der Bau des 2,9 km langen Trojane Tunnels mit zwei Autobahnroehren erfolgte unter schwierigsten g... more Der Bau des 2,9 km langen Trojane Tunnels mit zwei Autobahnroehren erfolgte unter schwierigsten geotechnischen und anderen Randbedingungen - wie die Unterfahrung der Ortschaft Trojane mit sehr geringer Ueberdeckung. Das Gebirge besteht aus Ton-, Schluff- und untergeordnet Sandsteinen, die durch intensive Tektonik verfaltet, ueberschoben und letztlich von zwei konjugierten Scherzonen zerlegt und geschwaecht wurden. Neben dem generellen, eher chaotischen Verschiebungsverhalten des Tunnels - primaer durch lokale Stoerungen gesteuert - lassen sich einige Abschnitte mit einem charakteristischen Verschiebungsmuster ueber laengere Tunnelabschnitte feststellen. Vier typische Situationen werden berichtet: Fall 1 mit unueblichen Laengsverschiebungen des gesamten Tunnels (10 bis 15 cm) ueber eine Laenge von rund 120 m, Fall 2 behandelt gegenlaeufige Laengsverschiebungen der Tunnelulme, Fall 3 zwei typische Verschiebungsmuster im Zusammenhang mit lokalen Synklinalen und Antiklinalen und schlies...
The seismic behaviour of a building on a liquefiable deposit is a complex interaction which invol... more The seismic behaviour of a building on a liquefiable deposit is a complex interaction which involves quantifying both shaking induced damage and permanent ground deformation-related damage. In this paper the key parameters that influence both surface shaking and foundation settlements have been identified as the depth, thickness and liquefaction resistance of an equivalent liquefiable layer. These parameters can be used to develop an ‘equivalent soil profile’ that is analogous to the equivalent single degree-of-freedom that reduces the complexity of the dynamic response of a building into comparable and easily understood quantities. The equivalent soil profile is quantified independent of the seismic hazard, making it compatible with performance based design and assessment frameworks such that the building and soil profile can be directly assessed at different levels of seismic hazard. Several numerical studies are presented that demonstrate the influence of these key parameters on the ground surface shaking and foundation settlement. A set of criteria are proposed for classifying soil profiles into 22 different soil classes for regional loss assessment. An algorithm was developed for automatically fitting the equivalent soil profile to a cone penetration test trace and issues with the fitting are discussed. Field reconnaissance was undertaken to collect additional data to support existing datasets on the performance of buildings in Adapazari, during the 1999 Kocaeli, Turkey, earthquake (Mw = 7.4). The field case history data was used to investigate the correlation between the depth, thickness and liquefaction resistance of an equivalent liquefiable layer, on the extent of foundation permanent deformation. The case history data showed that in general a shallow, thick and weak liquefiable layer near the surface results in significant settlement but a lack of data for buildings on non-liquefiable deposits and the additional complexities involved with real buildings and soil deposits, meant that the trends observed in the idealised numerical models could not identified in the field case history data set.
Abstract The paper presents an extension of a recently developed fully coupled elastoplastic meth... more Abstract The paper presents an extension of a recently developed fully coupled elastoplastic method (Pulko and Logar, 2016) for the analysis of a poroelastic thick-walled soil cylinder around an elastoplastic end-bearing stone column to account for the influence of an elastic geosynthetic encasement. The method was developed in the framework of Biot's consolidation theory (Biot, 1941) and is based on a unit cell concept, wherein the column encasement is modeled as a thin elastic membrane, which can only sustain tension and acts in the radial direction. Analytical closed-form expressions for excess pore pressures, stresses, strains, displacements and encasement forces were derived in the Laplace domain. The final elastoplastic solution in time domain was obtained numerically by using efficient numerical scheme for the inverse Laplace transform. The validity of the solution was checked against finite element analyses and compared with previously developed analytical methods. The results showing the influence of column encasement on transient state of settlements, strains, excess pore pressures and encasement forces under instantaneous or time dependent load are presented and discussed.
The three large landslides that occured in Slovenia in past few years and threaten the population... more The three large landslides that occured in Slovenia in past few years and threaten the population and infrastructure were relatively well investigated geologically and geomechanically. One of common characteristics of all three landslides is the occurence of fast debris flows. One part of laboratory investigations was therefore focused into the study of materials that under given circumstances transform into debris flow. In addition to standard geomechanical investigations their behaviour was tested also in rheometer. In the paper the results of all laboratory tests are compared for the mentioned three landslides. The results of rheometer tests showed a consistency between test results and material behaviour on site for two tested materials.
This paper focuses on the design phase of I-BIM tunnelling projects using Sequential Excavation M... more This paper focuses on the design phase of I-BIM tunnelling projects using Sequential Excavation Method (SEM), in Europe, commonly referred to as the New Austrian Tunnelling Method (NATM), and addresses the problem of coupling geotechnical conditions and tunnelling Building Information Model (BIM) for the preparation of the computational model suitable for the finite element analysis method (FEM). The review of the literature led to the conclusion that an automatic merging of the tunnel model and ground model for use in the FEM software is currently not reliable due to the number of differences between various types of models as they serve contrasting needs. Consequently, modelling becomes a manual task, which is very time-consuming and error prone. In this paper, we present the development of a framework for the semiautomatic transformation of the various tunnelling models and respective ground models into the model suitable for further analysis. We conclude that the import and tran...
The development of the Port of Koper started in 1957 in the Gulf of Koper at the northern coast o... more The development of the Port of Koper started in 1957 in the Gulf of Koper at the northern coast of the old town. The first berths constructed on flysch bedrock soon became insufficient for the growing activity of the young port and the development of additional berths had to move to the area where thick deposits of soft marine clay dominated. The paper briefly describes the history of the development of the Port of Koper and presents some selected case histories from its construction.
The proposed manuscript presents an application of neural networks for predicting the displacemen... more The proposed manuscript presents an application of neural networks for predicting the displacement of two landslides, one with maximum displacement rate of a few meters per day and one with a fraction of millimiter per day, using observed rainfall as the only predictor. The issue is relevant because it applies to real-time monitoring of active landslides, with obvious impact on lives and infrastructure, and it is well within the Journal’s aims and scope.
ABSTRACT: In Slovenia first DMT tests were performed in the beginning of 2003. Slovenia is a smal... more ABSTRACT: In Slovenia first DMT tests were performed in the beginning of 2003. Slovenia is a small country, covering only 20 500 km, but with very complex geology. The assessment of ground properties is therefore a demanding task and methods that provide profiles of material properties rather than individual material data are very important. A CPT test with pore pressure measurements has been extensively used in the past. Ménard pressuremeter tests have also been used to complement CPT. Marchetti flat dilatometer tests have proven to be a fast and reliable tool when material properties are required for the assessment of stability and settlements for different geotechnical structures. The paper presents some first comparisons of DMT results with other soil investigation techniques, including laboratory and in situ tests, such as vane test, CPT and Ménard pressuremeter. Measured and predicted settlements are compared at three locations. During the first three years of the use of DMT t...
Der Bau des 2,9 km langen Trojane Tunnels mit zwei Autobahnroehren erfolgte unter schwierigsten g... more Der Bau des 2,9 km langen Trojane Tunnels mit zwei Autobahnroehren erfolgte unter schwierigsten geotechnischen und anderen Randbedingungen - wie die Unterfahrung der Ortschaft Trojane mit sehr geringer Ueberdeckung. Das Gebirge besteht aus Ton-, Schluff- und untergeordnet Sandsteinen, die durch intensive Tektonik verfaltet, ueberschoben und letztlich von zwei konjugierten Scherzonen zerlegt und geschwaecht wurden. Neben dem generellen, eher chaotischen Verschiebungsverhalten des Tunnels - primaer durch lokale Stoerungen gesteuert - lassen sich einige Abschnitte mit einem charakteristischen Verschiebungsmuster ueber laengere Tunnelabschnitte feststellen. Vier typische Situationen werden berichtet: Fall 1 mit unueblichen Laengsverschiebungen des gesamten Tunnels (10 bis 15 cm) ueber eine Laenge von rund 120 m, Fall 2 behandelt gegenlaeufige Laengsverschiebungen der Tunnelulme, Fall 3 zwei typische Verschiebungsmuster im Zusammenhang mit lokalen Synklinalen und Antiklinalen und schlies...
The seismic behaviour of a building on a liquefiable deposit is a complex interaction which invol... more The seismic behaviour of a building on a liquefiable deposit is a complex interaction which involves quantifying both shaking induced damage and permanent ground deformation-related damage. In this paper the key parameters that influence both surface shaking and foundation settlements have been identified as the depth, thickness and liquefaction resistance of an equivalent liquefiable layer. These parameters can be used to develop an ‘equivalent soil profile’ that is analogous to the equivalent single degree-of-freedom that reduces the complexity of the dynamic response of a building into comparable and easily understood quantities. The equivalent soil profile is quantified independent of the seismic hazard, making it compatible with performance based design and assessment frameworks such that the building and soil profile can be directly assessed at different levels of seismic hazard. Several numerical studies are presented that demonstrate the influence of these key parameters on the ground surface shaking and foundation settlement. A set of criteria are proposed for classifying soil profiles into 22 different soil classes for regional loss assessment. An algorithm was developed for automatically fitting the equivalent soil profile to a cone penetration test trace and issues with the fitting are discussed. Field reconnaissance was undertaken to collect additional data to support existing datasets on the performance of buildings in Adapazari, during the 1999 Kocaeli, Turkey, earthquake (Mw = 7.4). The field case history data was used to investigate the correlation between the depth, thickness and liquefaction resistance of an equivalent liquefiable layer, on the extent of foundation permanent deformation. The case history data showed that in general a shallow, thick and weak liquefiable layer near the surface results in significant settlement but a lack of data for buildings on non-liquefiable deposits and the additional complexities involved with real buildings and soil deposits, meant that the trends observed in the idealised numerical models could not identified in the field case history data set.
Abstract The paper presents an extension of a recently developed fully coupled elastoplastic meth... more Abstract The paper presents an extension of a recently developed fully coupled elastoplastic method (Pulko and Logar, 2016) for the analysis of a poroelastic thick-walled soil cylinder around an elastoplastic end-bearing stone column to account for the influence of an elastic geosynthetic encasement. The method was developed in the framework of Biot's consolidation theory (Biot, 1941) and is based on a unit cell concept, wherein the column encasement is modeled as a thin elastic membrane, which can only sustain tension and acts in the radial direction. Analytical closed-form expressions for excess pore pressures, stresses, strains, displacements and encasement forces were derived in the Laplace domain. The final elastoplastic solution in time domain was obtained numerically by using efficient numerical scheme for the inverse Laplace transform. The validity of the solution was checked against finite element analyses and compared with previously developed analytical methods. The results showing the influence of column encasement on transient state of settlements, strains, excess pore pressures and encasement forces under instantaneous or time dependent load are presented and discussed.
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Papers by Janko Logar