Pub Date : 2023-03-16DOI: 10.1080/19386362.2023.2227498
Mohammed Sulaimaan Kaizer Hassan, V. Loo
ABSTRACT The aim of this study is to assess the influence of 3D geometric variation on slope stability and to compare with the corresponding 2D analysis results. Homogeneous sand slopes with four slope geometries, namely, normal surfaces, curved surfaces, turning corners and turning arcs of various angles and slope inclinations, were analysed using PLAXIS LE. The 3D results demonstrated that the factor of safety of curved surface slopes will decrease with increasing concave curvature. For turning corner slopes, an increase in the concavity resulted in an increase in stability. When comparing the 3D and 2D results, the analysis showed that while most of the 2D analysis results yield a lower factor of safety than that of a 3D analysis, there were various concave slopes in which a 3D analysis was more conservative. The study also demonstrated that a 3D analysis is beneficial to capture slope failures spreading across the sloped surface, which can be used by practitioners to design more cost-effective stabilization measures.
{"title":"Effect of 3D geometric variation on slope stability for sandy slopes","authors":"Mohammed Sulaimaan Kaizer Hassan, V. Loo","doi":"10.1080/19386362.2023.2227498","DOIUrl":"https://doi.org/10.1080/19386362.2023.2227498","url":null,"abstract":"ABSTRACT The aim of this study is to assess the influence of 3D geometric variation on slope stability and to compare with the corresponding 2D analysis results. Homogeneous sand slopes with four slope geometries, namely, normal surfaces, curved surfaces, turning corners and turning arcs of various angles and slope inclinations, were analysed using PLAXIS LE. The 3D results demonstrated that the factor of safety of curved surface slopes will decrease with increasing concave curvature. For turning corner slopes, an increase in the concavity resulted in an increase in stability. When comparing the 3D and 2D results, the analysis showed that while most of the 2D analysis results yield a lower factor of safety than that of a 3D analysis, there were various concave slopes in which a 3D analysis was more conservative. The study also demonstrated that a 3D analysis is beneficial to capture slope failures spreading across the sloped surface, which can be used by practitioners to design more cost-effective stabilization measures.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"271 - 282"},"PeriodicalIF":1.9,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59987506","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}
Pub Date : 2023-03-16DOI: 10.1080/19386362.2023.2208921
Xuejun Li, S. Chi, C. Foster
ABSTRACT A Sobol sensitivity analysis is employed to identify the importance of parameters in the three-invariant soil model (GeoModel) for finite element simulation. Three commonly used sampling techniques, namely, pseudo-random, quasi-random (QR), and Latin-hypercube sampling (LHS), are investigated to determine the efficiency of each sampling technique for sensitivity analysis and identify the critical parameters for the soil model. Among the sampling methods, LHS shows the best sampling uniformity and offers more stable results and faster convergence than other methods. The analysis results also show that Young’s modulus and the initial value for the shear-yield surface are the most critical parameters for the designed outputs, which quantitatively measure the maximum total deformation (MD), plastic deformation (PV), and plastic zone size (VY). The proposed sensitivity analysis framework in this study can be applied to finite element simulations of similar engineering and scientific problems for assessing model parameters’ influence.
{"title":"Sensitivity analysis of a three-invariant plasticity model with different sampling algorithms","authors":"Xuejun Li, S. Chi, C. Foster","doi":"10.1080/19386362.2023.2208921","DOIUrl":"https://doi.org/10.1080/19386362.2023.2208921","url":null,"abstract":"ABSTRACT A Sobol sensitivity analysis is employed to identify the importance of parameters in the three-invariant soil model (GeoModel) for finite element simulation. Three commonly used sampling techniques, namely, pseudo-random, quasi-random (QR), and Latin-hypercube sampling (LHS), are investigated to determine the efficiency of each sampling technique for sensitivity analysis and identify the critical parameters for the soil model. Among the sampling methods, LHS shows the best sampling uniformity and offers more stable results and faster convergence than other methods. The analysis results also show that Young’s modulus and the initial value for the shear-yield surface are the most critical parameters for the designed outputs, which quantitatively measure the maximum total deformation (MD), plastic deformation (PV), and plastic zone size (VY). The proposed sensitivity analysis framework in this study can be applied to finite element simulations of similar engineering and scientific problems for assessing model parameters’ influence.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"221 - 233"},"PeriodicalIF":1.9,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43858714","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}
Pub Date : 2023-03-16DOI: 10.1080/19386362.2023.2208917
P. Kowalczyk
ABSTRACT This short communication identifies some inconsistencies in the numerical predictions of three advanced soil constitutive models. The chosen constitutive models are subject to simple numerical tests in the small-strain range relevant to the cyclic response of soil in seismic, offshore and urban applications. The numerical tests comprise a cyclic simple shear test in the small-strain range, a simple shear test with very small strain unloading-reloading loops and a test on the dependence of the rate of the shear stiffness degradation on the changing mean confining stress. The results are briefly discussed and, in some cases, the reasons for the observed inconsistencies and potential improvements in the formulations of the investigated constitutive models are initially drafted.
{"title":"Some remarks on the performance of three advanced soil constitutive models in the small-strain region","authors":"P. Kowalczyk","doi":"10.1080/19386362.2023.2208917","DOIUrl":"https://doi.org/10.1080/19386362.2023.2208917","url":null,"abstract":"ABSTRACT This short communication identifies some inconsistencies in the numerical predictions of three advanced soil constitutive models. The chosen constitutive models are subject to simple numerical tests in the small-strain range relevant to the cyclic response of soil in seismic, offshore and urban applications. The numerical tests comprise a cyclic simple shear test in the small-strain range, a simple shear test with very small strain unloading-reloading loops and a test on the dependence of the rate of the shear stiffness degradation on the changing mean confining stress. The results are briefly discussed and, in some cases, the reasons for the observed inconsistencies and potential improvements in the formulations of the investigated constitutive models are initially drafted.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"310 - 319"},"PeriodicalIF":1.9,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44630296","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}
Pub Date : 2023-02-07DOI: 10.1080/19386362.2023.2199662
Berjees Anisa Ikra, Jay X. Wang
ABSTRACT The research presented in this paper was focused on a numerical model predicting moisture content fluctuation in expansive subgrades. The model leads to a mechanism-based calculation of the vertical movement of a pavement sitting on expansive soils due to climate changes. The model was created using VADOSE/W in analysing changes in moisture content over a certain period of time, with climate and environmental effects take as imposed boundary and initial conditions. Moisture content fluctuations from the numerical analyses were validated by the long-term moisture content measurements below the pavement of country road FM-2 on the expansive Frelsburg clay near the city of College Station in Texas, U.S.A. VADSOSE/W was then applied to analyse the pavement of I-220 at Bossier Parish, Louisiana, U.S.A., which sits on subgrades of highly expansive Moreland clay in northern Louisiana. The numerical modelling was completed for a one-year period with input climatic and environmental data.
{"title":"Numerical investigation of the effect of water content variations in expansive clay subgrades","authors":"Berjees Anisa Ikra, Jay X. Wang","doi":"10.1080/19386362.2023.2199662","DOIUrl":"https://doi.org/10.1080/19386362.2023.2199662","url":null,"abstract":"ABSTRACT The research presented in this paper was focused on a numerical model predicting moisture content fluctuation in expansive subgrades. The model leads to a mechanism-based calculation of the vertical movement of a pavement sitting on expansive soils due to climate changes. The model was created using VADOSE/W in analysing changes in moisture content over a certain period of time, with climate and environmental effects take as imposed boundary and initial conditions. Moisture content fluctuations from the numerical analyses were validated by the long-term moisture content measurements below the pavement of country road FM-2 on the expansive Frelsburg clay near the city of College Station in Texas, U.S.A. VADSOSE/W was then applied to analyse the pavement of I-220 at Bossier Parish, Louisiana, U.S.A., which sits on subgrades of highly expansive Moreland clay in northern Louisiana. The numerical modelling was completed for a one-year period with input climatic and environmental data.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"140 - 150"},"PeriodicalIF":1.9,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42369232","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}
Pub Date : 2023-02-07DOI: 10.1080/19386362.2023.2195730
Rowshon Jadid, A. R. Shahriar, Md Rejwanur Rahman, Subashish Kundu Sunny
ABSTRACT The present study aims at investigating the behaviour of concrete anchor blocks in cohesionless soil through numerical modelling. A three-dimensional finite element analysis using PLAXIS 3D was conducted to examine the effect of various factors, including anchor shape, embedment depth, and the presence of a groundwater table, on the pullout resistance of anchor blocks. The results showed that anchor shape affects the pullout resistance, particularly for anchor blocks with small aspect ratios. The presence of groundwater table between the ground surface and the base of the anchor block affects the pullout resistance of the anchor block. Based on the results, an empirical correlation was developed to account for the effect of the groundwater table on pullout capacity. The study also compared different pullout capacity prediction models with the results of the numerical simulations for varying embedment depth ratios. The failure modes of the soil body were critically observed and discussed.
{"title":"Three-dimensional finite element analysis of a vertical anchor embedded in granular soil","authors":"Rowshon Jadid, A. R. Shahriar, Md Rejwanur Rahman, Subashish Kundu Sunny","doi":"10.1080/19386362.2023.2195730","DOIUrl":"https://doi.org/10.1080/19386362.2023.2195730","url":null,"abstract":"ABSTRACT The present study aims at investigating the behaviour of concrete anchor blocks in cohesionless soil through numerical modelling. A three-dimensional finite element analysis using PLAXIS 3D was conducted to examine the effect of various factors, including anchor shape, embedment depth, and the presence of a groundwater table, on the pullout resistance of anchor blocks. The results showed that anchor shape affects the pullout resistance, particularly for anchor blocks with small aspect ratios. The presence of groundwater table between the ground surface and the base of the anchor block affects the pullout resistance of the anchor block. Based on the results, an empirical correlation was developed to account for the effect of the groundwater table on pullout capacity. The study also compared different pullout capacity prediction models with the results of the numerical simulations for varying embedment depth ratios. The failure modes of the soil body were critically observed and discussed.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"209 - 218"},"PeriodicalIF":1.9,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45848265","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}
Pub Date : 2023-02-07DOI: 10.1080/19386362.2023.2182500
Yi Lu, E. Leong, Liang Zeng, Changhao Xu, Bingcheng Li
ABSTRACT The aim of the study is to develop charts to select the most suitable stabilizer (i.e. cement, lime and fly ash) for excavated soils and rocks (ESR) to improve their engineering behaviour. The suitability charts were developed based on considerations of soil gradation and plasticity. Data from the literature where cement, lime and fly ash (FA) were used to improve soil strength were collated. Based on the normalized unconfined compressive strength (UCS) of the soils, zones of various degree of soil strength improvement for cement, lime and FA were identified. The suitability charts were validated using data from the literature not used in the development of the suitability charts. New data on kaolin and three ESRs from Guangzhou improved with cement, lime and FA. The suitability charts correctly indicated that lime is most suitable for kaolin while cement is most suitable for red soil and silty sand.
{"title":"Suitability charts to select stabilizer for excavated soils and rocks (ESR)","authors":"Yi Lu, E. Leong, Liang Zeng, Changhao Xu, Bingcheng Li","doi":"10.1080/19386362.2023.2182500","DOIUrl":"https://doi.org/10.1080/19386362.2023.2182500","url":null,"abstract":"ABSTRACT The aim of the study is to develop charts to select the most suitable stabilizer (i.e. cement, lime and fly ash) for excavated soils and rocks (ESR) to improve their engineering behaviour. The suitability charts were developed based on considerations of soil gradation and plasticity. Data from the literature where cement, lime and fly ash (FA) were used to improve soil strength were collated. Based on the normalized unconfined compressive strength (UCS) of the soils, zones of various degree of soil strength improvement for cement, lime and FA were identified. The suitability charts were validated using data from the literature not used in the development of the suitability charts. New data on kaolin and three ESRs from Guangzhou improved with cement, lime and FA. The suitability charts correctly indicated that lime is most suitable for kaolin while cement is most suitable for red soil and silty sand.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"108 - 123"},"PeriodicalIF":1.9,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48718290","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}
Pub Date : 2023-02-07DOI: 10.1080/19386362.2023.2208919
Heitor Cardoso Bernardes, Aleones José da Cruz Junior, Maurício Martines Sales, Renato Pinto da Cunha, Juan Félix Rodríguez Rebolledo
ABSTRACT The design of foundations for buildings subjected to unload–reload cycles generate the need to understand the reloading effects in piles. Commonly, such foundations are found in unsaturated soils, which also requires considering the effects of matric suction. This paper investigates the effects of soil suction and reloading on the behaviour of piles from an experimental and numerical approach. A bored pile built on a tropical soil profile was subjected to a sequence of load tests, performed at different climate seasons. An average 85% decrease in soil suction was measured from the pile load test in the dry season to the test in the rainy one, which contributed to a reduction in the pile’s ultimate axial load capacity and stiffness of around 50%. The unload–reload cycles caused an increase on the pile’s ultimate load capacity between 7% and 9% and on the pile stiffness between 13% and 24%.
{"title":"Suction and reloading effects on pile behaviour in tropical soil","authors":"Heitor Cardoso Bernardes, Aleones José da Cruz Junior, Maurício Martines Sales, Renato Pinto da Cunha, Juan Félix Rodríguez Rebolledo","doi":"10.1080/19386362.2023.2208919","DOIUrl":"https://doi.org/10.1080/19386362.2023.2208919","url":null,"abstract":"ABSTRACT The design of foundations for buildings subjected to unload–reload cycles generate the need to understand the reloading effects in piles. Commonly, such foundations are found in unsaturated soils, which also requires considering the effects of matric suction. This paper investigates the effects of soil suction and reloading on the behaviour of piles from an experimental and numerical approach. A bored pile built on a tropical soil profile was subjected to a sequence of load tests, performed at different climate seasons. An average 85% decrease in soil suction was measured from the pile load test in the dry season to the test in the rainy one, which contributed to a reduction in the pile’s ultimate axial load capacity and stiffness of around 50%. The unload–reload cycles caused an increase on the pile’s ultimate load capacity between 7% and 9% and on the pile stiffness between 13% and 24%.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"177 - 189"},"PeriodicalIF":1.9,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42566416","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}
Pub Date : 2023-02-07DOI: 10.1080/19386362.2023.2202595
Trabelsi Houcem, Y. Alassaf, M. Jamei, S. Olivella
ABSTRACT This paper focuses on the cracking of fine soil grains by desiccation using a 3D hydro-mechanical model. It further seeks to study the cracks growth across the depth during the desiccation time. Numerical results provide data for assessing the depth propagation of the cracks, field suction in 3D, the tensile stresses caused by the cracks. Cross sections have been considered to determine the cracks’ depth. Furthermore, water content and suction versus time have been obtained. It is still challenging to experimentally obtain a sample’s suction, water content, and distribution of stresses. Although there is a gap between numerical and experimental results concerning the appearance time of the first crack, the interpretation given in the text demonstrates that it is a wrong gap. Consequently, it can be stated that the numerical results agree with the experimental results, in terms of cracks intensity factor (CIF) and the evaporation rate as functions of desiccation time.
{"title":"Desiccation cracks prediction using a 3D finite elements model","authors":"Trabelsi Houcem, Y. Alassaf, M. Jamei, S. Olivella","doi":"10.1080/19386362.2023.2202595","DOIUrl":"https://doi.org/10.1080/19386362.2023.2202595","url":null,"abstract":"ABSTRACT This paper focuses on the cracking of fine soil grains by desiccation using a 3D hydro-mechanical model. It further seeks to study the cracks growth across the depth during the desiccation time. Numerical results provide data for assessing the depth propagation of the cracks, field suction in 3D, the tensile stresses caused by the cracks. Cross sections have been considered to determine the cracks’ depth. Furthermore, water content and suction versus time have been obtained. It is still challenging to experimentally obtain a sample’s suction, water content, and distribution of stresses. Although there is a gap between numerical and experimental results concerning the appearance time of the first crack, the interpretation given in the text demonstrates that it is a wrong gap. Consequently, it can be stated that the numerical results agree with the experimental results, in terms of cracks intensity factor (CIF) and the evaporation rate as functions of desiccation time.","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"162 - 176"},"PeriodicalIF":1.9,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43230957","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}
Pub Date : 2023-02-07DOI: 10.1080/19386362.2023.2191237
Tanumaya Mitra, K. Chattopadhyay, Ambarish Ghosh
ABSTRACT This paper presents a new coupled approach to incorporate the effect of vertical load on lateral response of pile in clay, by considering both the lateral and vertical strain of the soil-pile system. Experimental and numerical studies on pile subjected to combined loading carried out by different researchers showed that coupling behaviour cannot be modelled using Beams on Winkler foundation or subgrade reaction approach and use of continuum modelling is essential. However, in this present study an is made to develop a method using FEM by utilizing both the lateral and vertical strain of soil-pile system. The proposed coupled method is capable of simulating the influence of vertical load on lateral response of pile in clayey deposit much more realistically compared to uncoupled method. However, this coupling effect is more prominent for pile subjected to a vertical load equal to ultimate pile capacity (Vu), compared to pile under a load equal to allowable pile capacity (Vall).
{"title":"Influence of vertical load on lateral response of pile in clayey deposit considering Winkler model using FEM","authors":"Tanumaya Mitra, K. Chattopadhyay, Ambarish Ghosh","doi":"10.1080/19386362.2023.2191237","DOIUrl":"https://doi.org/10.1080/19386362.2023.2191237","url":null,"abstract":"ABSTRACT This paper presents a new coupled approach to incorporate the effect of vertical load on lateral response of pile in clay, by considering both the lateral and vertical strain of the soil-pile system. Experimental and numerical studies on pile subjected to combined loading carried out by different researchers showed that coupling behaviour cannot be modelled using Beams on Winkler foundation or subgrade reaction approach and use of continuum modelling is essential. However, in this present study an is made to develop a method using FEM by utilizing both the lateral and vertical strain of soil-pile system. The proposed coupled method is capable of simulating the influence of vertical load on lateral response of pile in clayey deposit much more realistically compared to uncoupled method. However, this coupling effect is more prominent for pile subjected to a vertical load equal to ultimate pile capacity (Vu), compared to pile under a load equal to allowable pile capacity (Vall).","PeriodicalId":47238,"journal":{"name":"International Journal of Geotechnical Engineering","volume":"17 1","pages":"190 - 208"},"PeriodicalIF":1.9,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41738292","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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