Pub Date : 2024-11-12DOI: 10.1016/j.sandf.2024.101529
Antonio Souza , Ana Claudia Telles , David Reid , Andy Fourie , Marcio Almeida
A series of lateral extrusion (LE) tests were carried out on silica fine sand using the triaxial device to study the initiation of instability under various drainage conditions on this stress path. All specimens were reconstituted using the moist tamping technique, having achieved state parameter (ψ0) values between −0.020 and +0.086 after anisotropic consolidation. The LE stress path consists in a decrease of mean effective stress and increase of the deviator stress at a constant rate, maintaining the vertical stress constant. The LE tests were performed either with the drainage valves open or with undrained increments followed by drainage. Different magnitudes of undrained increments were tested. For the same initial state parameter, the results indicated that the instability stress ratio (IL) decreases as drainage conditions changes from drained to undrained/drained increments. As the magnitude of the undrained increment increases, IL decreases. Further, consistent with previous studies, the test data shows that the static liquefaction can be triggered in tests where the drainage valves are open, generating high values of excess of pore pressure only after the onset of instability. The results were also compared to results from CSD and CAU tests.
{"title":"Instability of sand under a lateral extrusion stress path with different drainage conditions","authors":"Antonio Souza , Ana Claudia Telles , David Reid , Andy Fourie , Marcio Almeida","doi":"10.1016/j.sandf.2024.101529","DOIUrl":"10.1016/j.sandf.2024.101529","url":null,"abstract":"<div><div>A series of lateral extrusion (LE) tests were carried out on silica fine sand using the triaxial device to study the initiation of instability under various drainage conditions on this stress path. All specimens were reconstituted using the moist tamping technique, having achieved state parameter (ψ<sub>0</sub>) values between −0.020 and +0.086 after anisotropic consolidation. The LE stress path consists in a decrease of mean effective stress and increase of the deviator stress at a constant rate, maintaining the vertical stress constant. The LE tests were performed either with the drainage valves open or with undrained increments followed by drainage. Different magnitudes of undrained increments were tested. For the same initial state parameter, the results indicated that the instability stress ratio (<span><math><mrow><mi>η</mi></mrow></math></span><em><sub>IL</sub></em>) decreases as drainage conditions changes from drained to undrained/drained increments. As the magnitude of the undrained increment increases, <span><math><mrow><mi>η</mi></mrow></math></span><em><sub>IL</sub></em> decreases. Further, consistent with previous studies, the test data shows that the static liquefaction can be triggered in tests where the drainage valves are open, generating high values of excess of pore pressure only after the onset of instability. The results were also compared to results from CSD and CAU tests.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101529"},"PeriodicalIF":3.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.sandf.2024.101533
Shinichi Ito , Ryusei Fukunaga , Kazunari Sako
Physics-informed neural networks (PINNs) have been proposed for incorporating physical laws into deep learning. PINNs can output solutions that satisfy physical laws by introducing information, such as partial differential equations (PDEs), boundary conditions, and initial conditions, into the loss functions used during the construction of the neural network model. This study presents two cases in which geotechnical parameters were estimated through an inverse analysis of PINNs. PINNs were applied to simulate consolidation and unsaturated seepage processes. The inverse analysis of the PINNs helped estimate the coefficient of consolidation and the parameters related to the unsaturated soil hydraulic properties with sufficient accuracy. The inverse analysis of PINNs for geotechnical parameter estimation was found to be an effective approach that utilizes measurement data.
{"title":"Inverse analysis for estimating geotechnical parameters using physics-informed neural networks","authors":"Shinichi Ito , Ryusei Fukunaga , Kazunari Sako","doi":"10.1016/j.sandf.2024.101533","DOIUrl":"10.1016/j.sandf.2024.101533","url":null,"abstract":"<div><div>Physics-informed neural networks (PINNs) have been proposed for incorporating physical laws into deep learning. PINNs can output solutions that satisfy physical laws by introducing information, such as partial differential equations (PDEs), boundary conditions, and initial conditions, into the loss functions used during the construction of the neural network model. This study presents two cases in which geotechnical parameters were estimated through an inverse analysis of PINNs. PINNs were applied to simulate consolidation and unsaturated seepage processes. The inverse analysis of the PINNs helped estimate the coefficient of consolidation and the parameters related to the unsaturated soil hydraulic properties with sufficient accuracy. The inverse analysis of PINNs for geotechnical parameter estimation was found to be an effective approach that utilizes measurement data.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101533"},"PeriodicalIF":3.3,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.sandf.2024.101535
Ibuki Nishimura, Hitoshi Matsubara
The natural erosion of sand along coastlines and in landfills is a complex phenomenon influenced by interactions among currents, waves, tides, and wind. Countermeasures against internal erosion in landfills often involve installing geotextile sheets and/or filters between seawalls and landfills. However, the mere installation of such structures proves insufficient for comprehensively monitoring and mitigating soil erosion, and ensuring adequate ground stability and safety is challenging. This study focuses on the application of electrodeposition for mitigating soil erosion and potentially repairing these structures. By applying a weak electric current to severely deteriorated objects, carbonate minerals, called electrodeposits, are deposited on the cathode side and can repair vulnerable areas through self-organized solidification. Experiments were conducted using various silica sand specimens to assess the applicability of electrodeposition to discrete sand. The results revealed that, in specimens with relatively large sand particles, such as those in silica sand No. 3, the sand adhered to the cathode, forming a solidified area approximately 15–17 mm high. A microstructural analysis indicated the presence of crystallized minerals resembling calcium carbonate bonding within the interstitial spaces between the sand particles. These experimental findings suggest that electrodeposition can be applied to enhance the stability and safety of sandy soil-based structures.
{"title":"Electrodeposition-based self-healing technique for structures with loosely compacted sand","authors":"Ibuki Nishimura, Hitoshi Matsubara","doi":"10.1016/j.sandf.2024.101535","DOIUrl":"10.1016/j.sandf.2024.101535","url":null,"abstract":"<div><div>The natural erosion of sand along coastlines and in landfills is a complex phenomenon influenced by interactions among currents, waves, tides, and wind. Countermeasures against internal erosion in landfills often involve installing geotextile sheets and/or filters between seawalls and landfills. However, the mere installation of such structures proves insufficient for comprehensively monitoring and mitigating soil erosion, and ensuring adequate ground stability and safety is challenging. This study focuses on the application of electrodeposition for mitigating soil erosion and potentially repairing these structures. By applying a weak electric current to severely deteriorated objects, carbonate minerals, called electrodeposits, are deposited on the cathode side and can repair vulnerable areas through self-organized solidification. Experiments were conducted using various silica sand specimens to assess the applicability of electrodeposition to discrete sand. The results revealed that, in specimens with relatively large sand particles, such as those in silica sand No. 3, the sand adhered to the cathode, forming a solidified area approximately 15–17 mm high. A microstructural analysis indicated the presence of crystallized minerals resembling calcium carbonate bonding within the interstitial spaces between the sand particles. These experimental findings suggest that electrodeposition can be applied to enhance the stability and safety of sandy soil-based structures.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101535"},"PeriodicalIF":3.3,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.sandf.2024.101531
T. Yoshida , R. Nomura , Y. Tuda , I. Yoshida , K. Terada , S. Moriguchi
The aim of this study was to analyze and model the effect of rock shapes on the run-out distribution characteristics of rockfalls. To this end, we conducted a parametric study of rockfall simulations using the discrete element method, which is a numerical simulation method capable of directly representing rock shapes. The results indicated a strong correlation between the sphericity of rocks and the run-out distribution characteristics, expressed by two types of sphericity. Furthermore, we developed a regression model that can predict the run-out distribution using these two sphericities and the parameters of the calculation conditions as the explanatory variables. Although there is some room for improvement in terms of the developed regression model, it was confirmed that the relationship between the sphericity of rocks and the run-out distribution characteristics suggests the potential to enhance efficient rockfall risk assessments through numerical analysis.
{"title":"Modeling effect of rock shape characteristics on run-out distribution of rockfalls","authors":"T. Yoshida , R. Nomura , Y. Tuda , I. Yoshida , K. Terada , S. Moriguchi","doi":"10.1016/j.sandf.2024.101531","DOIUrl":"10.1016/j.sandf.2024.101531","url":null,"abstract":"<div><div>The aim of this study was to analyze and model the effect of rock shapes on the run-out distribution characteristics of rockfalls. To this end, we conducted a parametric study of rockfall simulations using the discrete element method, which is a numerical simulation method capable of directly representing rock shapes. The results indicated a strong correlation between the sphericity of rocks and the run-out distribution characteristics, expressed by two types of sphericity. Furthermore, we developed a regression model that can predict the run-out distribution using these two sphericities and the parameters of the calculation conditions as the explanatory variables. Although there is some room for improvement in terms of the developed regression model, it was confirmed that the relationship between the sphericity of rocks and the run-out distribution characteristics suggests the potential to enhance efficient rockfall risk assessments through numerical analysis.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101531"},"PeriodicalIF":3.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.sandf.2024.101534
Qinji Jia, Xiaoming Liu, Xin Tan
Research on stratified rock masses, which are common geological formations, has primarily focused on their mechanical properties, while studies on crack evolution and microscopic damage mechanisms remain limited. This study addresses this gap by investigating the combined effects of strength ratios and soft layer thicknesses on the microcrack evolution mechanism of stratified rocks using the discrete element method (DEM). Through FISH language programming in the particle flow code (PFC), this study reveals the acoustic emission (AE) characteristics, crack initiation and propagation, damage degree, and final failure characteristics. The key findings are: (1) Higher strength ratios between the hard and soft components of stratified rocks make specimens more sensitive to increases in soft layer thickness. (2) Three types of AE events were identified: continuous active, intermittent active, and silent. (3) Cracks initiate at the interface between components and propagate along the interface into the rock matrix. The strength ratios determine the crack propagation path and the damage extent of the components. (4) The failure of stratified rocks is primarily controlled by the soft component. Crack connections typically form vertical and sub-vertical tensile failure planes in the hard component, and a shear failure surface with a “V”-shaped intersection in the soft component.
{"title":"Crack evolution mechanism of stratified rock mass under different strength ratios and soft layer thickness: Insights from DEM modeling","authors":"Qinji Jia, Xiaoming Liu, Xin Tan","doi":"10.1016/j.sandf.2024.101534","DOIUrl":"10.1016/j.sandf.2024.101534","url":null,"abstract":"<div><div>Research on stratified rock masses, which are common geological formations, has primarily focused on their mechanical properties, while studies on crack evolution and microscopic damage mechanisms remain limited. This study addresses this gap by investigating the combined effects of strength ratios and soft layer thicknesses on the microcrack evolution mechanism of stratified rocks using the discrete element method (DEM). Through FISH language programming in the particle flow code (PFC), this study reveals the acoustic emission (AE) characteristics, crack initiation and propagation, damage degree, and final failure characteristics. The key findings are: (1) Higher strength ratios between the hard and soft components of stratified rocks make specimens more sensitive to increases in soft layer thickness. (2) Three types of AE events were identified: continuous active, intermittent active, and silent. (3) Cracks initiate at the interface between components and propagate along the interface into the rock matrix. The strength ratios determine the crack propagation path and the damage extent of the components. (4) The failure of stratified rocks is primarily controlled by the soft component. Crack connections typically form vertical and sub-vertical tensile failure planes in the hard component, and a shear failure surface with a “V”-shaped intersection in the soft component.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101534"},"PeriodicalIF":3.3,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.sandf.2024.101527
Maher Omar , Mohamed G. Arab , Emran Alotaibi , Khalid A. Alshibli , Abdallah Shanableh , Hussein Elmehdi , Dima A. Hussien Malkawi , Ali Tahmaz
The deformation characteristics and constitutive behavior of granular materials under normal forces acting on particles are dependent on the geometry of the grain structure, fabrics and the inter-particle friction. In this study, the influence of particle morphology on the friction and dilatancy of five natural sands was investigated using deep learning (DL) techniques. A Three-dimensional (3D) imaging technique using computed tomography was utilized to compute the morphology (roundness and sphericity) of collected natural sands. Triaxial tests were conducted on the five different natural sands at different densities and confinement stresses (σ3). From the triaxial results, peak friction angle (, critical state friction angle (), and dilatancy angle (ψ) were obtained and modeled using conventional multiple linear regression (MLR) models and DL techniques. A total of 100 deep artificial neural networks (DANN) models were trained at different sizes of first and second hidden layers. The use of MLR resulted in R2 of 0.709, 0.565, and 0.795 for , and ψ, respectively, while the best performed DANN (30 and 50 neurons for the 1st and 2nd hidden layers, respectively) had R2 of 0.956 for all outputs (, and ψ) combined. Using the best-performed DANN model, the weight partitioning technique was used to compute an importance score for each parameter in predicting , and ψ. The σ3 had the highest importance followed by relative density, roundness, and sphericity with a relative importance of more than 10%. In addition, sensitivity analysis was conducted to investigate the effect of each parameter on the shear parameters and ensure the robustness of the developed model.
{"title":"Natural soils’ shear strength prediction: A morphological data-centric approach","authors":"Maher Omar , Mohamed G. Arab , Emran Alotaibi , Khalid A. Alshibli , Abdallah Shanableh , Hussein Elmehdi , Dima A. Hussien Malkawi , Ali Tahmaz","doi":"10.1016/j.sandf.2024.101527","DOIUrl":"10.1016/j.sandf.2024.101527","url":null,"abstract":"<div><div>The deformation characteristics and constitutive behavior of granular materials under normal forces acting on particles are dependent on the geometry of the grain structure, fabrics and the inter-particle friction. In this study, the influence of particle morphology on the friction and dilatancy of five natural sands was investigated using deep learning (DL) techniques. A Three-dimensional (3D) imaging technique using computed tomography was utilized to compute the morphology (roundness and sphericity) of collected natural sands. Triaxial tests were conducted on the five different natural sands at different densities and confinement stresses (<em>σ<sub>3</sub></em>). From the triaxial results, peak friction angle (<span><math><mrow><msub><mi>φ</mi><mi>p</mi></msub><mrow><mo>)</mo></mrow></mrow></math></span>, critical state friction angle (<span><math><mrow><msub><mi>φ</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub></mrow></math></span>), and dilatancy angle (ψ) were obtained and modeled using conventional multiple linear regression (MLR) models and DL techniques. A total of 100 deep artificial neural networks (DANN) models were trained at different sizes of first and second hidden layers. The use of MLR resulted in R<sup>2</sup> of 0.709, 0.565, and 0.795 for <span><math><mrow><msub><mi>φ</mi><mi>p</mi></msub></mrow></math></span>, <span><math><mrow><msub><mi>φ</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub></mrow></math></span> and <em>ψ</em>, respectively, while the best performed DANN (30 and 50 neurons for the 1st and 2nd hidden layers, respectively) had R<sup>2</sup> of 0.956 for all outputs (<span><math><mrow><msub><mi>φ</mi><mi>p</mi></msub></mrow></math></span>, <span><math><mrow><msub><mi>φ</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub></mrow></math></span> and <em>ψ</em>) combined. Using the best-performed DANN model, the weight partitioning technique was used to compute an importance score for each parameter in predicting <span><math><mrow><msub><mi>φ</mi><mi>p</mi></msub></mrow></math></span>, <span><math><mrow><msub><mi>φ</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub></mrow></math></span> and <em>ψ</em>. The <em>σ<sub>3</sub></em> had the highest importance followed by relative density, roundness, and sphericity with a relative importance of more than 10%. In addition, sensitivity analysis was conducted to investigate the effect of each parameter on the shear parameters and ensure the robustness of the developed model.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101527"},"PeriodicalIF":3.3,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S-wave velocity (Vs) profile or time averaged Vs to 30 m depth (VS30) is indispensable information to estimate the local site amplification of ground motion from earthquakes. We use a horizontal-to-vertical spectral ratio (H/V) of seismic ambient noise to estimate the Vs profiles or VS30. The measurement of H/V is easier, compared to active surface wave methods (MASW) or microtremor array measurements (MAM). The inversion of H/V is non-unique and it is impossible to obtain unique Vs profiles. We apply deep learning to estimate the Vs profile from H/V together with other information including site coordinates, deep bedrock depths, and geomorphological classification. The pairs of H/V spectra (input layer) and Vs profiles (output layer) are used as training data. An input layer consists of an observed H/V spectrum, site coordinates, deep bedrock depths, and geomorphological classification, and an output layer is a velocity profile. We applied the method to the South Kanto Plain, Japan. We measured MASW, MAM and H/V at approximately 2300 sites. The pairs of H/V spectrum together with their coordinates, geomorphological classification etc. and Vs profile obtained from the inversion of dispersion curve and H/V, compose the training data. A trained neural network predicts Vs profiles from the observed H/V spectra with other information. Predicted Vs profiles and their VS30 are reasonably consistent with true Vs profiles and their VS30. The results implied that the deep learning could estimate Vs profile from H/V together with other information.
S 波速度（Vs）剖面或 30 米深度的时间平均 Vs（VS30）是估算地震引起的地面运动的局部场地放大效应不可或缺的信息。我们使用地震环境噪声的水平-垂直频谱比（H/V）来估算 Vs 剖面或 VS30。与主动表面波方法（MASW）或微震源阵列测量（MAM）相比，H/V 的测量更为简单。H/V 的反演是非唯一的，因此不可能获得唯一的 Vs 剖面。我们采用深度学习方法，从 H/V 和其他信息（包括站点坐标、深基岩深度和地貌分类）中估算 Vs 剖面。H/V 光谱（输入层）和 Vs 剖面（输出层）对作为训练数据。输入层包括观测到的 H/V 光谱、站点坐标、深基岩深度和地貌分类，输出层为速度剖面。我们将该方法应用于日本南关东平原。我们在大约 2300 个地点测量了 MASW、MAM 和 H/V。H/V频谱对及其坐标、地貌分类等以及通过反演频散曲线和H/V获得的Vs剖面构成了训练数据。经过训练的神经网络根据观测到的 H/V 光谱和其他信息预测 Vs 剖面。预测的 Vs 曲线及其 VS30 与真实的 Vs 曲线及其 VS30 基本一致。这些结果表明，深度学习可以根据 H/V 和其他信息来估计 Vs 曲线。
{"title":"Estimating S-wave velocity profiles from horizontal-to-vertical spectral ratios based on deep learning","authors":"Koichi Hayashi , Toru Suzuki , Tomio Inazaki , Chisato Konishi , Haruhiko Suzuki , Hisanori Matsuyama","doi":"10.1016/j.sandf.2024.101525","DOIUrl":"10.1016/j.sandf.2024.101525","url":null,"abstract":"<div><div>S-wave velocity (Vs) profile or time averaged Vs to 30 m depth (V<sub>S30</sub>) is indispensable information to estimate the local site amplification of ground motion from earthquakes. We use a horizontal-to-vertical spectral ratio (H/V) of seismic ambient noise to estimate the Vs profiles or V<sub>S30</sub>. The measurement of H/V is easier, compared to active surface wave methods (MASW) or microtremor array measurements (MAM). The inversion of H/V is non-unique and it is impossible to obtain unique Vs profiles. We apply deep learning to estimate the Vs profile from H/V together with other information including site coordinates, deep bedrock depths, and geomorphological classification. The pairs of H/V spectra (input layer) and Vs profiles (output layer) are used as training data. An input layer consists of an observed H/V spectrum, site coordinates, deep bedrock depths, and geomorphological classification, and an output layer is a velocity profile. We applied the method to the South Kanto Plain, Japan. We measured MASW, MAM and H/V at approximately 2300 sites. The pairs of H/V spectrum together with their coordinates, geomorphological classification etc. and Vs profile obtained from the inversion of dispersion curve and H/V, compose the training data. A trained neural network predicts Vs profiles from the observed H/V spectra with other information. Predicted Vs profiles and their V<sub>S30</sub> are reasonably consistent with true Vs profiles and their V<sub>S30</sub>. The results implied that the deep learning could estimate Vs profile from H/V together with other information.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101525"},"PeriodicalIF":3.3,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.sandf.2024.101532
Pongpipat Anantanasakul , Victor N. Kaliakin
This paper investigates shear banding as a possible failure mode for silt–clay transition soils under general three-dimensional stress conditions. Drained and undrained true triaxial tests with constant values were performed on tall prismatic specimens of such soils with systematically varying silt contents. Based on the values of critical plastic hardening modulus, shear banding does not govern the strength characteristics of the soils for values less than 0.2. For larger values, shear band formation is essentially critical as it takes place in the hardening regime of the stress–strain curves prior to the smooth peak failure points. An increase in silt content appears to move the onset of shear banding to lower levels of shear in the stress–strain relations of the silt–clay transition soils. It is also demonstrated that a non-associated constitutive model with a single hardening law is capable of accurately predicting the onset of shear banding in normally consolidated silt–clay transition soils based on bifurcation theory.
本文研究了淤泥-粘土过渡土在一般三维应力条件下可能的破坏模式--剪切带。在淤泥含量系统变化的此类土的高棱柱试样上进行了恒定 b 值的排水和不排水真三轴试验。根据临界塑性硬化模量值，当 b 值小于 0.2 时，剪切带并不影响土壤的强度特性。对于较大的 b 值，剪切带的形成基本上是临界的，因为它发生在应力-应变曲线的硬化阶段，在光滑的峰值破坏点之前。在淤泥-粘土过渡土壤的应力-应变关系中，淤泥含量的增加似乎会使剪切带的形成转移到较低的剪切水平。研究还证明，基于分岔理论，具有单一硬化规律的非关联构造模型能够准确预测正常固结的粉砂-粘土过渡土壤中剪切带的出现。
{"title":"Shear band analysis of silt-clay transition soils under three-dimensional stress-strain conditions","authors":"Pongpipat Anantanasakul , Victor N. Kaliakin","doi":"10.1016/j.sandf.2024.101532","DOIUrl":"10.1016/j.sandf.2024.101532","url":null,"abstract":"<div><div>This paper investigates shear banding as a possible failure mode for silt–clay transition soils under general three-dimensional stress conditions. Drained and undrained true triaxial tests with constant <span><math><mi>b</mi></math></span> values were performed on tall prismatic specimens of such soils with systematically varying silt contents. Based on the values of critical plastic hardening modulus, shear banding does not govern the strength characteristics of the soils for <span><math><mi>b</mi></math></span> values less than 0.2. For larger <span><math><mi>b</mi></math></span> values, shear band formation is essentially critical as it takes place in the hardening regime of the stress–strain curves prior to the smooth peak failure points. An increase in silt content appears to move the onset of shear banding to lower levels of shear in the stress–strain relations of the silt–clay transition soils. It is also demonstrated that a non-associated constitutive model with a single hardening law is capable of accurately predicting the onset of shear banding in normally consolidated silt–clay transition soils based on bifurcation theory.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101532"},"PeriodicalIF":3.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-25DOI: 10.1016/j.sandf.2024.101505
Zhan-liang Wang , Wu-zhen Kang , Fu-quan Chen , Cheng Lin
A solution method for the determination of seismic passive earth pressures in narrow cohesive backfill behind gravity walls has been developed using the stress characteristics method. The stress characteristics method is combined with the pseudo-static method in the analysis to consider the effects of seismic forces. The failure mechanisms of backfill are complex when the backfill reaches its passive limit state. The stress characteristics method does not require pre-assumptions about the sliding surface and the plastic region of the backfill. This method automatically calculates the position of the sliding surface. The reliability and reasonableness of the proposed method are verified by comparing the sliding surface and seismic passive earth pressure calculated in this paper with the finite element calculation results, the existing experimental research results and the existing theoretical solution results. The effect of different parameters on seismic passive earth pressure is investigated by internal stress clouds of the backfill and the distribution of passive earth pressure on the retaining wall.
{"title":"Seismic passive earth pressures of narrow cohesive backfill against gravity walls using the stress characteristics method","authors":"Zhan-liang Wang , Wu-zhen Kang , Fu-quan Chen , Cheng Lin","doi":"10.1016/j.sandf.2024.101505","DOIUrl":"10.1016/j.sandf.2024.101505","url":null,"abstract":"<div><div>A solution method for the determination of seismic passive earth pressures in narrow cohesive backfill behind gravity walls has been developed using the stress characteristics method. The stress characteristics method is combined with the pseudo-static method in the analysis to consider the effects of seismic forces. The failure mechanisms of backfill are complex when the backfill reaches its passive limit state. The stress characteristics method does not require pre-assumptions about the sliding surface and the plastic region of the backfill. This method automatically calculates the position of the sliding surface. The reliability and reasonableness of the proposed method are verified by comparing the sliding surface and seismic passive earth pressure calculated in this paper with the finite element calculation results, the existing experimental research results and the existing theoretical solution results. The effect of different parameters on seismic passive earth pressure is investigated by internal stress clouds of the backfill and the distribution of passive earth pressure on the retaining wall.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101505"},"PeriodicalIF":3.3,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1016/j.sandf.2024.101530
Haotian Guo , Yuli Lin , Jinming Li , Chao Sun
In order to examine the principles governing the variation of dynamic characteristic parameters, including the damping ratio, dynamic modulus, and frozen soil backbone curve, under different negative temperature conditions, silty clays sourced from the Changchun region were selected for the research. Dynamic loading studies were carried out on silty clays under different negative temperature conditions using a temperature-controlled GDS dynamic triaxial machine. The results demonstrated that the lower the temperature, the higher the dynamic stress required to achieve the same dynamic strain. The inverse of the dynamic modulus is linearly related to the dynamic strain, and the intercept of the fitted line of the inverse of decreases with decreasing temperature. The damping ratio and ability to absorb vibration waves decrease as the temperature drops. As the temperature decreases, the maximum dynamic modulus gradually increases, and the maximum damping ratio has the opposite trend. The temperature correction formulas for the maximum dynamic modulus and maximum damping ratio of silty clay are proposed by correlation analysis method based on test data.
{"title":"Experimental study and correction of dynamic characteristic parameters of silty clay under negative temperature conditions","authors":"Haotian Guo , Yuli Lin , Jinming Li , Chao Sun","doi":"10.1016/j.sandf.2024.101530","DOIUrl":"10.1016/j.sandf.2024.101530","url":null,"abstract":"<div><div>In order to examine the principles governing the variation of dynamic characteristic parameters, including the damping ratio, dynamic modulus, and frozen soil backbone curve, under different negative temperature conditions, silty clays sourced from the Changchun region were selected for the research. Dynamic loading studies were carried out on silty clays under different negative temperature conditions using a temperature-controlled GDS dynamic triaxial machine. The results demonstrated that the lower the temperature, the higher the dynamic stress required to achieve the same dynamic strain. The inverse of the dynamic modulus <span><math><mrow><mn>1</mn><mo>/</mo><msub><mi>E</mi><mi>d</mi></msub></mrow></math></span> is linearly related to the dynamic strain, and the intercept of the fitted line of the inverse of <span><math><mrow><mn>1</mn><mo>/</mo><msub><mi>E</mi><mi>d</mi></msub></mrow></math></span> decreases with decreasing temperature. The damping ratio and ability to absorb vibration waves decrease as the temperature drops. As the temperature decreases, the maximum dynamic modulus gradually increases, and the maximum damping ratio has the opposite trend. The temperature correction formulas for the maximum dynamic modulus and maximum damping ratio of silty clay are proposed by correlation analysis method based on test data.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101530"},"PeriodicalIF":3.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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