Pub Date : 2024-11-15DOI: 10.1016/j.sandf.2024.101539
Wengang Zhang , Bo Ran , Xin Gu , Yanmei Zhang , Yulin Zou , Peiqing Wang
Reservoir slope stability during water level drawdown has drawn increasing concern in geotechnical engineering in recent years. In this study, an efficient reliability analysis framework based on the extreme gradient boosting (XGBoost) surrogate model is employed to evaluate the failure probability of unsaturated slopes subjected to the rapid drawdown considering the depth-dependent properties of spatially varying soils. A c-φ slope is selected as an illustrative example to investigate the coupled influence of the non-stationary characteristic of shear strength parameters and saturated hydraulic conductivity, as well as water level drawdown velocity, maximum drop height and scale of fluctuation on the slope failure probability. Results show that the adopted framework can estimate the low-level probability of slope failure with high accuracy and efficiency. It is found that the velocity and maximum height of water level drawdown have a significant effect on the unsaturated slope stability. Furthermore, it is recommended that the depth-dependent non-stationary soil properties be considered in most cases to ensure a more accurate result.
{"title":"Efficient reliability analysis of unsaturated slope stability under rapid drawdown using XGBoost-based surrogate model","authors":"Wengang Zhang , Bo Ran , Xin Gu , Yanmei Zhang , Yulin Zou , Peiqing Wang","doi":"10.1016/j.sandf.2024.101539","DOIUrl":"10.1016/j.sandf.2024.101539","url":null,"abstract":"<div><div>Reservoir slope stability during water level drawdown has drawn increasing concern in geotechnical engineering in recent years. In this study, an efficient reliability analysis framework based on the extreme gradient boosting (XGBoost) surrogate model is employed to evaluate the failure probability of unsaturated slopes subjected to the rapid drawdown considering the depth-dependent properties of spatially varying soils. A <em>c</em>-<em>φ</em> slope is selected as an illustrative example to investigate the coupled influence of the non-stationary characteristic of shear strength parameters and saturated hydraulic conductivity, as well as water level drawdown velocity, maximum drop height and scale of fluctuation on the slope failure probability. Results show that the adopted framework can estimate the low-level probability of slope failure with high accuracy and efficiency. It is found that the velocity and maximum height of water level drawdown have a significant effect on the unsaturated slope stability. Furthermore, it is recommended that the depth-dependent non-stationary soil properties be considered in most cases to ensure a more accurate result.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101539"},"PeriodicalIF":3.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663552","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 : 2024-11-14DOI: 10.1016/j.sandf.2024.101537
Adnan Anwar Malik , Shekh Istiaq Ahmed , Umair Ali , Syed Kamran Hussain Shah , Jiro Kuwano
The advantages of using screw piles are quite evident nowadays, which enhances its importance in the field of deep foundations. Moreover, the current environmental challenges direct the construction industry towards sustainability, creating more opportunities for such type of piling techniques to be used in the future. Therefore, more investigation is required to optimise screw pile performance in terms of ultimate bearing capacity associated with installation efforts. To explore further, the current study focused on the effect of the advancement ratio on ultimate bearing capacity and work done due to installation load and torque. The model scale of testing is adopted, and two kinds of ground (using Toyoura sand), i.e., scenario I: loose sand over dense sand and scenario II: loose sand, are prepared to install the single helix screw pile. In the case of scenario I, the screw is installed up to 1 times the helix diameter into the dense bearing layer. Based on the experimental results, it was observed that as the advancement ratio (from 0.25 to 1.25) increased, the installation load also increased. On the other hand, the installation torque decreased with the increase in advancement ratio. This was due to the increase in the number of rotations per pitch penetration and the resultant movement of sand particles. The change in the state of the ground around the screw pile is strongly related to the advancement ratio and initial density. The ideal advancement ratio (1.0) is difficult to attain in the field due to high pressing load demand; empirical equations are developed, which can be used to estimate the increase/decrease of ultimate bearing capacity and associated installation requirements in terms of work done for the initial design stage.
如今，使用螺旋桩的优势非常明显，这提高了其在深基础领域的重要性。此外，当前的环境挑战将建筑行业引向可持续发展的方向，这为未来使用此类打桩技术创造了更多机会。因此，需要进行更多研究，以优化螺旋桩在与安装工作相关的极限承载力方面的性能。为了进一步探索，本次研究重点关注了推进比对最终承载力以及安装荷载和扭矩所做功的影响。试验采用模型比例，准备了两种地面（使用丰浦砂）来安装单螺旋式螺旋桩，即情况 I：松散砂覆盖密集砂和情况 II：松散砂。在情况 I 中，螺旋安装到 1 倍螺旋直径的致密承载层中。实验结果表明，随着推进比（从 0.25 到 1.25）的增加，安装载荷也随之增加。另一方面，安装扭矩随着推进比的增加而减小。这是由于每个螺距插入的旋转次数增加以及由此产生的沙粒移动所致。螺旋桩周围地面状态的变化与推进比和初始密度密切相关。理想的推进比（1.0）在现场很难达到，因为压载需求很高；我们开发了经验公式，可用于估算极限承载力的增加/减少以及初始设计阶段所需的相关安装工作量。
{"title":"Advancement ratio effect on screw pile performance in the bearing layer","authors":"Adnan Anwar Malik , Shekh Istiaq Ahmed , Umair Ali , Syed Kamran Hussain Shah , Jiro Kuwano","doi":"10.1016/j.sandf.2024.101537","DOIUrl":"10.1016/j.sandf.2024.101537","url":null,"abstract":"<div><div>The advantages of using screw piles are quite evident nowadays, which enhances its importance in the field of deep foundations. Moreover, the current environmental challenges direct the construction industry towards sustainability, creating more opportunities for such type of piling techniques to be used in the future. Therefore, more investigation is required to optimise screw pile performance in terms of ultimate bearing capacity associated with installation efforts. To explore further, the current study focused on the effect of the advancement ratio on ultimate bearing capacity and work done due to installation load and torque. The model scale of testing is adopted, and two kinds of ground (using Toyoura sand), i.e., scenario I: loose sand over dense sand and scenario II: loose sand, are prepared to install the single helix screw pile. In the case of scenario I, the screw is installed up to 1 times the helix diameter into the dense bearing layer. Based on the experimental results, it was observed that as the advancement ratio (from 0.25 to 1.25) increased, the installation load also increased. On the other hand, the installation torque decreased with the increase in advancement ratio. This was due to the increase in the number of rotations per pitch penetration and the resultant movement of sand particles. The change in the state of the ground around the screw pile is strongly related to the advancement ratio and initial density. The ideal advancement ratio (1.0) is difficult to attain in the field due to high pressing load demand; empirical equations are developed, which can be used to estimate the increase/decrease of ultimate bearing capacity and associated installation requirements in terms of work done for the initial design stage.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101537"},"PeriodicalIF":3.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663550","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 : 2024-11-13DOI: 10.1016/j.sandf.2024.101538
Yun Que , Jisong Zhang , Yu Tian , Xiaosong Li
Mountain road construction often involves crossing numerous ravine terrains. To ensure road safety, numerous shoulder retaining walls are built to stabilize the roadbed. However, the limitations imposed by gullies result in significant spatial effects on the soil pressure distribution behind the walls, rendering traditional two-dimensional soil pressure theories inadequate. To investigate the spatial distribution of active earth pressure on clayey fill behind the walls, this paper presents a three-dimensional theoretical solution for earth pressure on V-type retaining walls in gully terrains, using theoretical analysis and numerical simulation. The results indicate that the clayey fill causes a slip crack behind the wall, forming a tension crack region with zero earth pressure, the depth of which increases with the fill’s cohesive force. Additionally, the earth pressure distribution behind the V-type retaining wall exhibits a significant spatial effect, being “larger in the middle and smaller at the ends” along the wall’s width. Compared to traditional two-dimensional theories, the earth pressure predicted by this spatial theory is lower, and the resultant force location is higher, and the overturning resistance in region III is largest. Therefore, this part should be enhanced in construction design.
山区公路建设往往需要穿越众多峡谷地形。为了确保道路安全，需要修建大量路肩挡土墙来稳定路基。然而，由于沟壑的限制，墙后的土压力分布会受到很大的空间影响，使得传统的二维土压力理论无法满足要求。为了研究墙后粘性填土上活动土压力的空间分布，本文采用理论分析和数值模拟的方法，提出了沟谷地形中 V 型挡土墙土压力的三维理论解。结果表明，粘土填料会在墙后造成滑移裂缝，形成土压力为零的拉伸裂缝区域，裂缝深度随填料内聚力的增加而增加。此外，V 型挡土墙后的土压力分布具有明显的空间效应，沿墙宽 "中间大，两端小"。与传统的二维理论相比，该空间理论预测的土压力较低，所产生的力位置较高，且区域 III 的抗倾覆能力最大。因此，在施工设计中应加强这一部分的设计。
{"title":"Spatial earth pressure analysis of clayey fill behind retaining wall in V-shaped gully terrain","authors":"Yun Que , Jisong Zhang , Yu Tian , Xiaosong Li","doi":"10.1016/j.sandf.2024.101538","DOIUrl":"10.1016/j.sandf.2024.101538","url":null,"abstract":"<div><div>Mountain road construction often involves crossing numerous ravine terrains. To ensure road safety, numerous shoulder retaining walls are built to stabilize the roadbed. However, the limitations imposed by gullies result in significant spatial effects on the soil pressure distribution behind the walls, rendering traditional two-dimensional soil pressure theories inadequate. To investigate the spatial distribution of active earth pressure on clayey fill behind the walls, this paper presents a three-dimensional theoretical solution for earth pressure on V-type retaining walls in gully terrains, using theoretical analysis and numerical simulation. The results indicate that the clayey fill causes a slip crack behind the wall, forming a tension crack region with zero earth pressure, the depth of which increases with the fill’s cohesive force. Additionally, the earth pressure distribution behind the V-type retaining wall exhibits a significant spatial effect, being “larger in the middle and smaller at the ends” along the wall’s width. Compared to traditional two-dimensional theories, the earth pressure predicted by this spatial theory is lower, and the resultant force location is higher, and the overturning resistance in region III is largest. Therefore, this part should be enhanced in construction design.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 6","pages":"Article 101538"},"PeriodicalIF":3.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663551","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 : 2024-11-12DOI: 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}
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