Aser Abbas, Mauro Aimar, M. Yust, Brady Cox, S. Foti
The in-situ small-strain shear modulus of soil and rock materials is a parameter of paramount importance in geotechnical modeling. It can be derived from non-invasive geophysical surveys, which provide the possibility of testing the subsurface in its natural and undisturbed condition by inferring the velocity of propagation of shear waves. In addition, for soil dynamics and earthquake engineering applications, the small-strain damping ratio plays a relevant role, yet its estimation is still challenging, lacking consolidated approaches for its in-situ evaluation. Recent advancements in instrumentation, such as distributed acoustic sensing (DAS), combined with advanced analysis methodologies for the interpretation of seismic wave propagation (e.g., machine learning and full waveform inversion), open new frontiers in site characterization. This paper presents and compares some advanced applications of measuring 1D and 2D variations in shear wave velocity and attenuation in-situ with reference to a specific case history.
{"title":"Emerging technologies and advanced analyses for non-invasive near-surface site characterization","authors":"Aser Abbas, Mauro Aimar, M. Yust, Brady Cox, S. Foti","doi":"10.28927/sr.2024.006923","DOIUrl":"https://doi.org/10.28927/sr.2024.006923","url":null,"abstract":"The in-situ small-strain shear modulus of soil and rock materials is a parameter of paramount importance in geotechnical modeling. It can be derived from non-invasive geophysical surveys, which provide the possibility of testing the subsurface in its natural and undisturbed condition by inferring the velocity of propagation of shear waves. In addition, for soil dynamics and earthquake engineering applications, the small-strain damping ratio plays a relevant role, yet its estimation is still challenging, lacking consolidated approaches for its in-situ evaluation. Recent advancements in instrumentation, such as distributed acoustic sensing (DAS), combined with advanced analysis methodologies for the interpretation of seismic wave propagation (e.g., machine learning and full waveform inversion), open new frontiers in site characterization. This paper presents and compares some advanced applications of measuring 1D and 2D variations in shear wave velocity and attenuation in-situ with reference to a specific case history.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":"74 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139861109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper discusses some points of the evolution of Engineering Geology based on a survey of historical facts, books, and other types of publications and technical reports and analyzes the teaching in engineering schools, specifically in the São Carlos School of Engineering, at University of São Paulo (EESC/USP). The survey involved the main topics considered in the teaching of Engineering Geology and both successes and challenges of the teaching experience at undergraduate and graduate levels at EESC/USP over the past 50 years are presented. Engineering Geology teaching has undergone different phases and adaptations to the evolution of knowledge and research procedures. According to the survey, it focuses on four large groups of didactic activities for the current decade and, perhaps, for the next one in several countries. The first group refers to access to materials of each topic in the format of books, videos, and lectures available on websites and the second includes face-to-face activities on the solution of practical problems related to a specific topic. The third group focuses on field and laboratory works, whereas the fourth comprehends development and analyses of specific civil work projects, mineral exploration, and environmental problems according to both face-to-face and non-face-to-face methodologies.
{"title":"Historical aspects and challenges of teaching engineering geology to engineering students","authors":"Rogério Ribeiro, O. Pejon, L. Zuquette","doi":"10.28927/sr.2024.006223","DOIUrl":"https://doi.org/10.28927/sr.2024.006223","url":null,"abstract":"This paper discusses some points of the evolution of Engineering Geology based on a survey of historical facts, books, and other types of publications and technical reports and analyzes the teaching in engineering schools, specifically in the São Carlos School of Engineering, at University of São Paulo (EESC/USP). The survey involved the main topics considered in the teaching of Engineering Geology and both successes and challenges of the teaching experience at undergraduate and graduate levels at EESC/USP over the past 50 years are presented. Engineering Geology teaching has undergone different phases and adaptations to the evolution of knowledge and research procedures. According to the survey, it focuses on four large groups of didactic activities for the current decade and, perhaps, for the next one in several countries. The first group refers to access to materials of each topic in the format of books, videos, and lectures available on websites and the second includes face-to-face activities on the solution of practical problems related to a specific topic. The third group focuses on field and laboratory works, whereas the fourth comprehends development and analyses of specific civil work projects, mineral exploration, and environmental problems according to both face-to-face and non-face-to-face methodologies.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":"20 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139809080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper discusses some points of the evolution of Engineering Geology based on a survey of historical facts, books, and other types of publications and technical reports and analyzes the teaching in engineering schools, specifically in the São Carlos School of Engineering, at University of São Paulo (EESC/USP). The survey involved the main topics considered in the teaching of Engineering Geology and both successes and challenges of the teaching experience at undergraduate and graduate levels at EESC/USP over the past 50 years are presented. Engineering Geology teaching has undergone different phases and adaptations to the evolution of knowledge and research procedures. According to the survey, it focuses on four large groups of didactic activities for the current decade and, perhaps, for the next one in several countries. The first group refers to access to materials of each topic in the format of books, videos, and lectures available on websites and the second includes face-to-face activities on the solution of practical problems related to a specific topic. The third group focuses on field and laboratory works, whereas the fourth comprehends development and analyses of specific civil work projects, mineral exploration, and environmental problems according to both face-to-face and non-face-to-face methodologies.
{"title":"Historical aspects and challenges of teaching engineering geology to engineering students","authors":"Rogério Ribeiro, O. Pejon, L. Zuquette","doi":"10.28927/sr.2024.006223","DOIUrl":"https://doi.org/10.28927/sr.2024.006223","url":null,"abstract":"This paper discusses some points of the evolution of Engineering Geology based on a survey of historical facts, books, and other types of publications and technical reports and analyzes the teaching in engineering schools, specifically in the São Carlos School of Engineering, at University of São Paulo (EESC/USP). The survey involved the main topics considered in the teaching of Engineering Geology and both successes and challenges of the teaching experience at undergraduate and graduate levels at EESC/USP over the past 50 years are presented. Engineering Geology teaching has undergone different phases and adaptations to the evolution of knowledge and research procedures. According to the survey, it focuses on four large groups of didactic activities for the current decade and, perhaps, for the next one in several countries. The first group refers to access to materials of each topic in the format of books, videos, and lectures available on websites and the second includes face-to-face activities on the solution of practical problems related to a specific topic. The third group focuses on field and laboratory works, whereas the fourth comprehends development and analyses of specific civil work projects, mineral exploration, and environmental problems according to both face-to-face and non-face-to-face methodologies.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":"20 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139868827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Environmental conditions have become a concern when involving the use of Geosynthetics clay liners (GCLs) as leachate barriers, particularly because they can be subjected to daily thermal cycles during construction and operation of landfills, which can affect their properties. This paper investigates the hydration behavior of a nonwoven geotextile carrier-GCL in contact with lateritic subsoils under isothermal and simulated thermal conditions as commonly found in tropical regions. A thermal insulate testing box was used to shelter an instrumented liner landfill allowing the investigation of thermal and hydraulic responses during hydration. Lateritic subsoils were observed not to provide high levels of GCLs hydration under isothermal conditions, whereas thermal daily cycles led to capillary break that restricted the moisture uptake at the interface between subsoil and the nonwoven geotextile carrier. Higher values of subsoil initial moisture contents were found to be significant to reduce capillary effects and to allow some GCL hydration. The poor hydration demonstrated to be critical in terms of GCL hydraulic behavior.
{"title":"Moisture uptake of a nonwoven geotextile carrier-GCL from Lateritic subsoils under simulated tropical thermal conditions","authors":"F. Portelinha, José Silva, Natalia Correia","doi":"10.28927/sr.2024.009722","DOIUrl":"https://doi.org/10.28927/sr.2024.009722","url":null,"abstract":"Environmental conditions have become a concern when involving the use of Geosynthetics clay liners (GCLs) as leachate barriers, particularly because they can be subjected to daily thermal cycles during construction and operation of landfills, which can affect their properties. This paper investigates the hydration behavior of a nonwoven geotextile carrier-GCL in contact with lateritic subsoils under isothermal and simulated thermal conditions as commonly found in tropical regions. A thermal insulate testing box was used to shelter an instrumented liner landfill allowing the investigation of thermal and hydraulic responses during hydration. Lateritic subsoils were observed not to provide high levels of GCLs hydration under isothermal conditions, whereas thermal daily cycles led to capillary break that restricted the moisture uptake at the interface between subsoil and the nonwoven geotextile carrier. Higher values of subsoil initial moisture contents were found to be significant to reduce capillary effects and to allow some GCL hydration. The poor hydration demonstrated to be critical in terms of GCL hydraulic behavior.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":" September","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139618165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Felipe Vitali, O. Vitali, Antonio Bobet, T. Celestino
Modern tunnel design in urban areas heavily relies on numerical modeling to assess excavation stability and predict ground movement. Recent advancements in soil modeling, hardware, and software have facilitated the development of sophisticated 3D models within tight schedules. Urban tunnels are often shallow and excavated in challenging ground conditions, with proximity to existing structures and infrastructure. Consequently, numerical modeling of such tunnels involves highly nonlinear analyses with complex boundary conditions. Despite the widespread use of numerical modeling in tunnel research and design, there is a lack of publications addressing modeling procedures to ensure accurate and reliable results for highly nonlinear shallow tunnel analyses. This paper investigates the requirements for accurate results for highly nonlinear shallow tunnel analyses. The Finite Element Method (FEM) is employed with different mesh refinements and element types. The study focuses on the hypothetical excavation stability scenario explored by Carranza-Torres et al. (2013). Tunnel stability is assessed using Caquot’s analytical solution based on the lower bound theorem of plasticity, as well as FEM modeling with the strength reduction method. The FEM numerical solution, which approaches the exact solution for the problem, provided a factor of safety slightly larger (2.3%) than Caquot’s lower-bound solution. The results of the FEM modeling indicate that a significantly less refined mesh is required to achieve accurate results for highly nonlinear shallow tunnel analyses when adopting 2nd-order elements (i.e., quadratic interpolation) instead of 1st-order elements (i.e., linear interpolation). This study improves our understanding of FEM modeling requirements and provides practical insights regarding the numerical modeling of highly nonlinear shallow tunnels in urban areas.
{"title":"FEM modeling requirements for accurate analysis of highly nonlinear shallow tunnels","authors":"Felipe Vitali, O. Vitali, Antonio Bobet, T. Celestino","doi":"10.28927/sr.2024.000923","DOIUrl":"https://doi.org/10.28927/sr.2024.000923","url":null,"abstract":"Modern tunnel design in urban areas heavily relies on numerical modeling to assess excavation stability and predict ground movement. Recent advancements in soil modeling, hardware, and software have facilitated the development of sophisticated 3D models within tight schedules. Urban tunnels are often shallow and excavated in challenging ground conditions, with proximity to existing structures and infrastructure. Consequently, numerical modeling of such tunnels involves highly nonlinear analyses with complex boundary conditions. Despite the widespread use of numerical modeling in tunnel research and design, there is a lack of publications addressing modeling procedures to ensure accurate and reliable results for highly nonlinear shallow tunnel analyses. This paper investigates the requirements for accurate results for highly nonlinear shallow tunnel analyses. The Finite Element Method (FEM) is employed with different mesh refinements and element types. The study focuses on the hypothetical excavation stability scenario explored by Carranza-Torres et al. (2013). Tunnel stability is assessed using Caquot’s analytical solution based on the lower bound theorem of plasticity, as well as FEM modeling with the strength reduction method. The FEM numerical solution, which approaches the exact solution for the problem, provided a factor of safety slightly larger (2.3%) than Caquot’s lower-bound solution. The results of the FEM modeling indicate that a significantly less refined mesh is required to achieve accurate results for highly nonlinear shallow tunnel analyses when adopting 2nd-order elements (i.e., quadratic interpolation) instead of 1st-order elements (i.e., linear interpolation). This study improves our understanding of FEM modeling requirements and provides practical insights regarding the numerical modeling of highly nonlinear shallow tunnels in urban areas.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":" 64","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139619276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Guimarães, C. Lima, F. Aragão, Laura Motta, Juliana Santos
Laterite gravels have been successfully adopted as pavement materials in the field. Despite that, they are often rejected in material selection processes because of its base on traditional gradation and consistency limits requirements. To allow a deeper evaluation of such material found abundantly in tropical countries, along to characterizing traditional parameters, repeated load triaxial tests were performed in a Laterite Gravel from Acre/Brazil to evaluate its elastic and plastic behavior through Resilient Modulus (RM) and Permanent Deformation (PD), respectively. In addition, a simulation was conducted in the MeDiNa software, based on the test results considering stress states that are usually applied in pavement layers. The material showed RM values higher than 500 MPa, which was considered high compared to materials such as Quartz and Granite. It was also observed low permanent deformation (below 1 mm for higher tensions applied) and accommodation of displacement (shakedown) for most specimens. The simulation results showed low rutting prediction for the Laterite Gravel applied in highway pavement layers. Thus, the results indicated that the lateritic gravel can be adopted in the composition of base or subbase layers of flexible pavements, even though some limits of the parameters specified by traditional specifications were violated, as expected. In addition, we also highlight the need for adoption of new material selection strategies that are based on key mechanical characteristics to avoid discarding potentially well performing materials.
{"title":"Mechanical characterization of an alternative laterite gravel used as pavement material","authors":"A. Guimarães, C. Lima, F. Aragão, Laura Motta, Juliana Santos","doi":"10.28927/sr.2024.010622","DOIUrl":"https://doi.org/10.28927/sr.2024.010622","url":null,"abstract":"Laterite gravels have been successfully adopted as pavement materials in the field. Despite that, they are often rejected in material selection processes because of its base on traditional gradation and consistency limits requirements. To allow a deeper evaluation of such material found abundantly in tropical countries, along to characterizing traditional parameters, repeated load triaxial tests were performed in a Laterite Gravel from Acre/Brazil to evaluate its elastic and plastic behavior through Resilient Modulus (RM) and Permanent Deformation (PD), respectively. In addition, a simulation was conducted in the MeDiNa software, based on the test results considering stress states that are usually applied in pavement layers. The material showed RM values higher than 500 MPa, which was considered high compared to materials such as Quartz and Granite. It was also observed low permanent deformation (below 1 mm for higher tensions applied) and accommodation of displacement (shakedown) for most specimens. The simulation results showed low rutting prediction for the Laterite Gravel applied in highway pavement layers. Thus, the results indicated that the lateritic gravel can be adopted in the composition of base or subbase layers of flexible pavements, even though some limits of the parameters specified by traditional specifications were violated, as expected. In addition, we also highlight the need for adoption of new material selection strategies that are based on key mechanical characteristics to avoid discarding potentially well performing materials.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139139377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the advent of critical state Soil Mechanics (CSSM), the void ratio began to be recognized as a key parameter, along with the stress state, which defines the mechanical behavior of soils and other particulate geomaterials by using the state parameter. The state parameter is the difference between the current and critical void ratio so that its definition requires the critical state line (CSL) identification. This work presents numerical calibration results, using the NorSand constitutive model, from three sets of triaxial compression tests selected from the literature. The SIGMA/W module of the Geostudio® System was adopted to perform the simulations of the triaxial compression tests, and the results showed adequate fit between real tests and numerical simulations. The parameters necessary for the modeling with NorSand model, defined from the numerical calibration, were used in a stress-strain evaluation of a hypothetical upstream tailings dam. These simulations allowed the evaluation of the differences in the tailings storage facility (TSF) responses in terms of both deformation behavior and flow liquefaction instability. Flow liquefaction instability is described in the literature as a complete loss in shear strength and the development of excessive strains due to the contractive response of tailings when subjected to low confining stress. The results suggest that the use of the NorSand model is, in general, a good option to reproduce the typical strain-softening behavior of such structures. Furthermore, it was clear the high sensitivity of the constitutive model parameters, drawing attention to the importance of best laboratory practices for carrying out triaxial tests to obtain reliable parameters for NorSand modeling.
{"title":"Numerical sensitivity analysis for stress-strain simulation and flow liquefaction assessment of tailings storage facilities using the NorSand constitutive model","authors":"Filipe Costa, B. Delgado, Breno Castilho","doi":"10.28927/sr.2024.011322","DOIUrl":"https://doi.org/10.28927/sr.2024.011322","url":null,"abstract":"With the advent of critical state Soil Mechanics (CSSM), the void ratio began to be recognized as a key parameter, along with the stress state, which defines the mechanical behavior of soils and other particulate geomaterials by using the state parameter. The state parameter is the difference between the current and critical void ratio so that its definition requires the critical state line (CSL) identification. This work presents numerical calibration results, using the NorSand constitutive model, from three sets of triaxial compression tests selected from the literature. The SIGMA/W module of the Geostudio® System was adopted to perform the simulations of the triaxial compression tests, and the results showed adequate fit between real tests and numerical simulations. The parameters necessary for the modeling with NorSand model, defined from the numerical calibration, were used in a stress-strain evaluation of a hypothetical upstream tailings dam. These simulations allowed the evaluation of the differences in the tailings storage facility (TSF) responses in terms of both deformation behavior and flow liquefaction instability. Flow liquefaction instability is described in the literature as a complete loss in shear strength and the development of excessive strains due to the contractive response of tailings when subjected to low confining stress. The results suggest that the use of the NorSand model is, in general, a good option to reproduce the typical strain-softening behavior of such structures. Furthermore, it was clear the high sensitivity of the constitutive model parameters, drawing attention to the importance of best laboratory practices for carrying out triaxial tests to obtain reliable parameters for NorSand modeling.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":" 48","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139141142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Roberto Coutinho, Jailson Alves, Hanna Moreira, Júlia Pontes, Wilson Ramos Aragão Júnior
Interferometry is a technique that can be applied to SAR (Synthetic Aperture Radar) images that allow obtaining Digital Elevation Models, displacement measurements and assistance for monitoring large areas and/or engineering constructions. The objective of this paper is to present aspects related to the technique of Interferometry SAR (InSAR) applied to the monitoring of slopes. To do so, a systematic bibliographical review was used, through research platforms in scientific collections, in order to highlight the functioning and method of operation of InSAR. Besides that, the practical experience of the authors contributed to a critical analysis of the remote sensing technique addressed. The results show theoretical aspects related to the operation of SARs on board satellites, highlighting their characteristics, orbital systems, types of imaging geometry, as well as the principles of interferometric processing of SAR images. Practical applications demonstrate the potential of InSAR with an emphasis on slope monitoring, highlighting its ability to acquire topographic information on a millimeter scale, monitoring the long-term temporal evolution of displacements, the possibility of composing a monitoring system allowing directing the implementation of other instruments for evaluating the in situ conditions and some limitations regarding the time interval (satellite revisit time) for the acquisition of the displacement data.
{"title":"Applicability of the InSAR technique for slope monitoring","authors":"Roberto Coutinho, Jailson Alves, Hanna Moreira, Júlia Pontes, Wilson Ramos Aragão Júnior","doi":"10.28927/sr.2023.008023","DOIUrl":"https://doi.org/10.28927/sr.2023.008023","url":null,"abstract":"Interferometry is a technique that can be applied to SAR (Synthetic Aperture Radar) images that allow obtaining Digital Elevation Models, displacement measurements and assistance for monitoring large areas and/or engineering constructions. The objective of this paper is to present aspects related to the technique of Interferometry SAR (InSAR) applied to the monitoring of slopes. To do so, a systematic bibliographical review was used, through research platforms in scientific collections, in order to highlight the functioning and method of operation of InSAR. Besides that, the practical experience of the authors contributed to a critical analysis of the remote sensing technique addressed. The results show theoretical aspects related to the operation of SARs on board satellites, highlighting their characteristics, orbital systems, types of imaging geometry, as well as the principles of interferometric processing of SAR images. Practical applications demonstrate the potential of InSAR with an emphasis on slope monitoring, highlighting its ability to acquire topographic information on a millimeter scale, monitoring the long-term temporal evolution of displacements, the possibility of composing a monitoring system allowing directing the implementation of other instruments for evaluating the in situ conditions and some limitations regarding the time interval (satellite revisit time) for the acquisition of the displacement data.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139220375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Landslides are widespread all over the world, often causing significant consequences in terms of loss of life and property damage. This explains why many scientists from Geology and Geotechnics have long been engaged in solving complex problems of both theoretical and practical interest. Geologists have systematically investigated the common characteristics of landslides proposing several classification systems, while not providing general laws for the triggering and evolution stages. Geotechnical engineers have implemented models to quantitatively analyze these stages but not to develop a general framework for typical landslide behaviors. Aimed to bridge the scientific branches dealing with landslides and based on the past efforts of many researchers all over the world, this paper focuses on deep-seated landslides developing along an existing and/or a new slip surface and multiple shallow landslides that may involve large areas in short periods of time. Considering that these phenomena are often analyzed at one single topographical scale and through monodisciplinary approaches, the paper proposes a new vision that highlights the possibility of a landslide management modern and open to the advanced technologies.
{"title":"The 1st Willy Alvarenga Lacerda lecture: New perspectives for landslide analysis and management","authors":"L. Cascini","doi":"10.28927/sr.2023.002723","DOIUrl":"https://doi.org/10.28927/sr.2023.002723","url":null,"abstract":"Landslides are widespread all over the world, often causing significant consequences in terms of loss of life and property damage. This explains why many scientists from Geology and Geotechnics have long been engaged in solving complex problems of both theoretical and practical interest. Geologists have systematically investigated the common characteristics of landslides proposing several classification systems, while not providing general laws for the triggering and evolution stages. Geotechnical engineers have implemented models to quantitatively analyze these stages but not to develop a general framework for typical landslide behaviors. Aimed to bridge the scientific branches dealing with landslides and based on the past efforts of many researchers all over the world, this paper focuses on deep-seated landslides developing along an existing and/or a new slip surface and multiple shallow landslides that may involve large areas in short periods of time. Considering that these phenomena are often analyzed at one single topographical scale and through monodisciplinary approaches, the paper proposes a new vision that highlights the possibility of a landslide management modern and open to the advanced technologies.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":"118 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139224255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lucas Takayassu, Cristian Camelo, Marcio Almeida, Maria Almeida, S. Madabhushi, R. Borges
Dynamic soil parameters such as the shear modulus suffer degradation while damping in soil increases under dynamic loading. These can be determined from various tests such as element tests, field tests and centrifuge experiments. Most of the studies about dynamic soil characterization have focused on evaluating these parameters assuming horizontal ground conditions without considering the effect of static shear stresses induced by ground inclination. This paper presents a dynamic centrifuge test conducted on a layered gentle slope comprising clay and sand, to obtain experimental data in terms of shear modulus and damping for various shear strains. Particle Image Velocimetry (PIV) was employed to measure the displacements and to calculate accelerations due to seismic loading at various depths throughout the slope model. The results suggest that the static shear stress caused by the profile inclination causes a more pronounced degradation of the shear modulus when compared to flat ground conditions. Moreover, the damping during the centrifuge test exhibited larger values than expected, following a similar behavior observed in other experimental programs. The strain rate analysis revealed the mobilization of shear stresses higher than the monotonic shear strength for the clay layers during the seismic shaking.
{"title":"Modeling of a soft clay gentle slope with sand layer in centrifuge under seismic loading: PIV and strain rate analysis","authors":"Lucas Takayassu, Cristian Camelo, Marcio Almeida, Maria Almeida, S. Madabhushi, R. Borges","doi":"10.28927/sr.2023.003223","DOIUrl":"https://doi.org/10.28927/sr.2023.003223","url":null,"abstract":"Dynamic soil parameters such as the shear modulus suffer degradation while damping in soil increases under dynamic loading. These can be determined from various tests such as element tests, field tests and centrifuge experiments. Most of the studies about dynamic soil characterization have focused on evaluating these parameters assuming horizontal ground conditions without considering the effect of static shear stresses induced by ground inclination. This paper presents a dynamic centrifuge test conducted on a layered gentle slope comprising clay and sand, to obtain experimental data in terms of shear modulus and damping for various shear strains. Particle Image Velocimetry (PIV) was employed to measure the displacements and to calculate accelerations due to seismic loading at various depths throughout the slope model. The results suggest that the static shear stress caused by the profile inclination causes a more pronounced degradation of the shear modulus when compared to flat ground conditions. Moreover, the damping during the centrifuge test exhibited larger values than expected, following a similar behavior observed in other experimental programs. The strain rate analysis revealed the mobilization of shear stresses higher than the monotonic shear strength for the clay layers during the seismic shaking.","PeriodicalId":507352,"journal":{"name":"Soils and Rocks","volume":"3 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139242736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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