Pub Date : 2026-05-01Epub Date: 2026-01-23DOI: 10.1016/j.compgeo.2026.107933
Ziwei Tian , Songzheng Yu , Hanyu Wang , Guang Zhang , Yiwei Liu , Yizhuo He , Quan Zheng , Guodong Liu , Xin Liu , Ronghua Pang , Guanghui Liu , Shijing He , Yang Li , Peng Zhang
Using high-resolution X-ray microscopy (XRM), the 3D structures of lunar regolith from the Chang’E-5 and Chang’E-6 missions were reconstructed, and a four-stage CNN-based volumetric segmentation framework was established to enable accurate extraction of tens of thousands of particles from both samples. Quantitative analysis shows that Chang’E-5 particles exhibit more elongated and irregular shapes (Aspect Ratio = 0.612, Elongation Index = 0.727, Flatness Index = 0.845) and higher energy contained in the high-degree spherical harmonic spectrum (0.0346) than Chang’E-6 (Aspect Ratio = 0.623, Elongation Index = 0.732, Flatness Index = 0.854; high-degree spectral energy = 0.0299), indicating rougher surfaces and lower maturity. XRM-derived porosity measurements further reveal a pronounced structural contrast, with porosities of 38.37 % for Chang’E-5 and 54.44 % for Chang’E-6, which leads to a substantial difference in their estimated bearing capacities. These results establish a direct quantitative link between micro-scale grain morphology, macro-scale regolith structure, and surface mechanical behavior, providing critical constraints for landing-site evaluation and lunar surface infrastructure design.
{"title":"High-fidelity digital modeling and comparative morphological analysis of Chang’E-5 and Chang’E-6 lunar grains","authors":"Ziwei Tian , Songzheng Yu , Hanyu Wang , Guang Zhang , Yiwei Liu , Yizhuo He , Quan Zheng , Guodong Liu , Xin Liu , Ronghua Pang , Guanghui Liu , Shijing He , Yang Li , Peng Zhang","doi":"10.1016/j.compgeo.2026.107933","DOIUrl":"10.1016/j.compgeo.2026.107933","url":null,"abstract":"<div><div>Using high-resolution X-ray microscopy (XRM), the 3D structures of lunar regolith from the Chang’E-5 and Chang’E-6 missions were reconstructed, and a four-stage CNN-based volumetric segmentation framework was established to enable accurate extraction of tens of thousands of particles from both samples. Quantitative analysis shows that Chang’E-5 particles exhibit more elongated and irregular shapes (Aspect Ratio = 0.612, Elongation Index = 0.727, Flatness Index = 0.845) and higher energy contained in the high-degree spherical harmonic spectrum (0.0346) than Chang’E-6 (Aspect Ratio = 0.623, Elongation Index = 0.732, Flatness Index = 0.854; high-degree spectral energy = 0.0299), indicating rougher surfaces and lower maturity. XRM-derived porosity measurements further reveal a pronounced structural contrast, with porosities of 38.37 % for Chang’E-5 and 54.44 % for Chang’E-6, which leads to a substantial difference in their estimated bearing capacities. These results establish a direct quantitative link between micro-scale grain morphology, macro-scale regolith structure, and surface mechanical behavior, providing critical constraints for landing-site evaluation and lunar surface infrastructure design.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107933"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-04DOI: 10.1016/j.compgeo.2026.107958
Pengju Wang , Gang Wang , Fulai Zhang , Changsheng Wang , Yujing Jiang
The microstructure of crystalline rock comprises mineral aggregates and randomly distributed microcracks that strongly govern macroscopic mechanical behavior. However, existing numerical approaches struggle to simultaneously capture finite-width microcrack closure, mineralogical heterogeneity, and realistic compressive-to-tensile strength ratios. This study develops a three-dimensional heterogeneous rock model within a finite–discrete element method (FDEM) framework that explicitly represents the polycrystalline mineral structure and embeds microcracks with prescribed intensity and finite aperture. Systematic uniaxial compression simulations on granite show that increasing microcrack width and intensity increases both crack-closure strain and crack-initiation strain, while decreasing crack-closure stress and crack-initiation stress. The crack-closure stage becomes more pronounced with increasing microcrack intensity and width, but via distinct mechanisms: higher intensity lowers the initial tangent modulus, whereas greater width extends the crack-closure strain range. Increasing microcrack intensity and width reduces elastic modulus and uniaxial compressive strength, with intensity exerting the stronger influence. As intensity increases, the failure mode transitions from localized shear fracture to diffuse fragmentation. Based on these parametric analyses, we establish an efficient calibration procedure for FDEM micromechanical parameters that incorporates microcrack characteristics. The calibrated model shows excellent agreement with laboratory measurements (relative errors < 5%), reproducing the nonlinear compaction stage and granite’s high compressive-to-tensile strength ratio. Applications to thermo–mechanical and hydro–mechanical coupling demonstrate that the model captures temperature-induced strength degradation and stress-controlled hydraulic fracture propagation in microcracked granite. This work provides a physically consistent framework for modeling the nonlinear compaction behavior and strength characteristics of crystalline rocks.
{"title":"A grain-based FDEM with finite-width microcracks for modeling granite deformation and strength","authors":"Pengju Wang , Gang Wang , Fulai Zhang , Changsheng Wang , Yujing Jiang","doi":"10.1016/j.compgeo.2026.107958","DOIUrl":"10.1016/j.compgeo.2026.107958","url":null,"abstract":"<div><div>The microstructure of crystalline rock comprises mineral aggregates and randomly distributed microcracks that strongly govern macroscopic mechanical behavior. However, existing numerical approaches struggle to simultaneously capture finite-width microcrack closure, mineralogical heterogeneity, and realistic compressive-to-tensile strength ratios. This study develops a three-dimensional heterogeneous rock model within a finite–discrete element method (FDEM) framework that explicitly represents the polycrystalline mineral structure and embeds microcracks with prescribed intensity and finite aperture. Systematic uniaxial compression simulations on granite show that increasing microcrack width and intensity increases both crack-closure strain and crack-initiation strain, while decreasing crack-closure stress and crack-initiation stress. The crack-closure stage becomes more pronounced with increasing microcrack intensity and width, but via distinct mechanisms: higher intensity lowers the initial tangent modulus, whereas greater width extends the crack-closure strain range. Increasing microcrack intensity and width reduces elastic modulus and uniaxial compressive strength, with intensity exerting the stronger influence. As intensity increases, the failure mode transitions from localized shear fracture to diffuse fragmentation. Based on these parametric analyses, we establish an efficient calibration procedure for FDEM micromechanical parameters that incorporates microcrack characteristics. The calibrated model shows excellent agreement with laboratory measurements (relative errors < 5%), reproducing the nonlinear compaction stage and granite’s high compressive-to-tensile strength ratio. Applications to thermo–mechanical and hydro–mechanical coupling demonstrate that the model captures temperature-induced strength degradation and stress-controlled hydraulic fracture propagation in microcracked granite. This work provides a physically consistent framework for modeling the nonlinear compaction behavior and strength characteristics of crystalline rocks.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107958"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-27DOI: 10.1016/j.compgeo.2026.107918
Gabriel Martins Cavalcanti Feitosa , Emanoel Rodrigues dos Santos , Pedro Victor Paixão Albuquerque , Artur Castiel Reis de Souza , Darlan Karlo Elisiário de Carvalho , Paulo Roberto Maciel Lyra
Modeling fluid flow in naturally fractured porous media is crucial for applications such as hydrocarbon production and CO2 sequestration. However, accurately simulating these flows remains challenging due to fractures with complex permeability distributions. The Embedded Discrete Fracture Model (EDFM) has been widely used but has limitations in representing fractures acting as barriers, especially in multiphase flows. To overcome these challenges, the Projection-based Embedded Discrete Fracture Model (pEDFM) was developed, offering better handling of fractures with lower permeability than the matrix. However, it can still exhibit discontinuities in fracture projections. To address these limitations, we propose the Continuous-Projection Embedded Discrete Fracture Model (CpEDFM-U), a graph-based algorithm that guarantees continuous fracture projections in both structured and unstructured 2D meshes. The CpEDFM-U uses Dijkstra’s algorithm to find the shortest path between fracture tips and applies the MPFA-D method for matrix flow and TPFA for fractures. In numerical simulations analyzed, CpEDFM-U outperforms EDFM and pEDFM, demonstrating lower errors and robust performance across different fracture types and mesh resolutions.
{"title":"A graph-based algorithm for the Continuous-Projection Embedded Discrete Fracture Model (CpEDFM-U) to simulate two-phase flows in naturally fractured porous media using the MPFA-D method on general unstructured meshes","authors":"Gabriel Martins Cavalcanti Feitosa , Emanoel Rodrigues dos Santos , Pedro Victor Paixão Albuquerque , Artur Castiel Reis de Souza , Darlan Karlo Elisiário de Carvalho , Paulo Roberto Maciel Lyra","doi":"10.1016/j.compgeo.2026.107918","DOIUrl":"10.1016/j.compgeo.2026.107918","url":null,"abstract":"<div><div>Modeling fluid flow in naturally fractured porous media is crucial for applications such as hydrocarbon production and CO2 sequestration. However, accurately simulating these flows remains challenging due to fractures with complex permeability distributions. The Embedded Discrete Fracture Model (EDFM) has been widely used but has limitations in representing fractures acting as barriers, especially in multiphase flows. To overcome these challenges, the Projection-based Embedded Discrete Fracture Model (pEDFM) was developed, offering better handling of fractures with lower permeability than the matrix. However, it can still exhibit discontinuities in fracture projections. To address these limitations, we propose the Continuous-Projection Embedded Discrete Fracture Model (CpEDFM-U), a graph-based algorithm that guarantees continuous fracture projections in both structured and unstructured 2D meshes. The CpEDFM-U uses Dijkstra’s algorithm to find the shortest path between fracture tips and applies the MPFA-D method for matrix flow and TPFA for fractures. In numerical simulations analyzed, CpEDFM-U outperforms EDFM and pEDFM, demonstrating lower errors and robust performance across different fracture types and mesh resolutions.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107918"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-30DOI: 10.1016/j.compgeo.2026.107951
Yuanping Li , Ruyang Yu , Xiaolong Yin , Huanquan Pan , Bin Gong , Lifeng Chen , Jingwei Huang
Particle clogging in porous media is a critical phenomenon with significant implications for geotechnical engineering, subsurface flow, and underground carbon storage. However, existing studies are limited to single-scale analysis, lacking multi-scale insights into the connections between simplified models and real porous media. To address these limitations, this study conducts a multi-scale investigation spanning single pores, homogeneous porous media, and digital rocks to elucidate clogging mechanisms. In the single-pore, three clogging regimes were identified: non-clogging, unstable clogging, and stable clogging. The critical thresholds of the three regimes were determined. In homogeneous porous medium, the clogging process could undergo three stages. Firstly, particles only blocked the dominant flow paths. Secondly, the new preferential pathways experience an increase in velocity and particle flux, leading to secondary clogging. Thirdly, the primary and secondary paths were mostly blocked, and a network of blockages was formed. The three clogging modes were summarized: selective channel clogging, localized bridging, and network-scale blockage, which are controlled by particle-to-throat size ratio, flow velocity and particle concentration. Network-scale blockages result in the most significant decline in permeability, while selective channel clogging leads to the least. In digital rocks, clogging exhibited the similar clogging behaviors observed in homogeneous porous media, but it exhibited distinct permeability loss due to the heterogeneity of realistic pore structures. This multi-scale study quantifies the regulatory effects of key parameters on clogging across scales, and identifies scale-specific patterns and mechanisms.
{"title":"CFD-DEM investigation on particle clogging in porous media at different scales: From single pore to digital rock","authors":"Yuanping Li , Ruyang Yu , Xiaolong Yin , Huanquan Pan , Bin Gong , Lifeng Chen , Jingwei Huang","doi":"10.1016/j.compgeo.2026.107951","DOIUrl":"10.1016/j.compgeo.2026.107951","url":null,"abstract":"<div><div>Particle clogging in porous media is a critical phenomenon with significant implications for geotechnical engineering, subsurface flow, and underground carbon storage. However, existing studies are limited to single-scale analysis, lacking multi-scale insights into the connections between simplified models and real porous media. To address these limitations, this study conducts a multi-scale investigation spanning single pores, homogeneous porous media, and digital rocks to elucidate clogging mechanisms. In the single-pore, three clogging regimes were identified: non-clogging, unstable clogging, and stable clogging. The critical thresholds of the three regimes were determined. In homogeneous porous medium, the clogging process could undergo three stages. Firstly, particles only blocked the dominant flow paths. Secondly, the new preferential pathways experience an increase in velocity and particle flux, leading to secondary clogging. Thirdly, the primary and secondary paths were mostly blocked, and a network of blockages was formed. The three clogging modes were summarized: selective channel clogging, localized bridging, and network-scale blockage, which are controlled by particle-to-throat size ratio, flow velocity and particle concentration. Network-scale blockages result in the most significant decline in permeability, while selective channel clogging leads to the least. In digital rocks, clogging exhibited the similar clogging behaviors observed in homogeneous porous media, but it exhibited distinct permeability loss due to the heterogeneity of realistic pore structures. This multi-scale study quantifies the regulatory effects of key parameters on clogging across scales, and identifies scale-specific patterns and mechanisms.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107951"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-16DOI: 10.1016/j.compgeo.2026.107992
Chuanxiang Qu , Yutong Liu , Haowen Guo , Yanbo Chen , Sheqiang Cui , Zhiyuan Yang
Fragility analysis is a key technique for probabilistically assessing slope performance and potential damage under various external loadings. Although previous studies have mainly focused on seismic scenarios, rainfall is also a significant trigger of slope failure, yet its impact on fragility has received limited attention. Stress states in the field affect soil hydraulic properties but are rarely included in rainfall-related fragility studies. To address these issues, this study conducts fragility analyses of an unsaturated soil slope subjected to various rainfall scenarios, explicitly incorporating stress effects. A stress-dependent water retention model is utilised to capture stress effects on soil hydraulic properties, while spatially variable soil hydraulic and mechanical parameters are modelled by multivariable cross-correlated random fields. The return period of rainfall (T) is used as an indicator of rainfall magnitude. It is found that ignoring the effects of stress on soil hydraulic properties significantly underestimates the probability of failure (pf) and associated risk of the slope. For T 50 years, this underestimation can reach up to 83% for pf and be as much as 6.7 times for failure risk, especially at shorter rainfall durations. This highlights the significance of incorporating stress effects, as the increasing frequency of short-duration extreme rainfall events under climate change. Different criteria for determining damage states influence the development of fragility curves, but minor damage is predominant. Rainfall events with larger T (i.e., more extreme rainfall) cause higher probabilities of slope failure and damage, which become even greater with longer rainfall durations at the same T. However, these rainfall events must occur first for the effects to be realised. This indicates that, apart from focusing on extreme rainfall, attention should also be directed toward prolonged rainfall durations with relatively low intensity, as their high likelihood of occurrence can also increase the probabilities of slope failure and damage.
{"title":"Probabilistic fragility analysis of unsaturated soil slope under rainfall infiltration considering stress-dependent water retention behaviour","authors":"Chuanxiang Qu , Yutong Liu , Haowen Guo , Yanbo Chen , Sheqiang Cui , Zhiyuan Yang","doi":"10.1016/j.compgeo.2026.107992","DOIUrl":"10.1016/j.compgeo.2026.107992","url":null,"abstract":"<div><div>Fragility analysis is a key technique for probabilistically assessing slope performance and potential damage under various external loadings. Although previous studies have mainly focused on seismic scenarios, rainfall is also a significant trigger of slope failure, yet its impact on fragility has received limited attention. Stress states in the field affect soil hydraulic properties but are rarely included in rainfall-related fragility studies. To address these issues, this study conducts fragility analyses of an unsaturated soil slope subjected to various rainfall scenarios, explicitly incorporating stress effects. A stress-dependent water retention model is utilised to capture stress effects on soil hydraulic properties, while spatially variable soil hydraulic and mechanical parameters are modelled by multivariable cross-correlated random fields. The return period of rainfall (<em>T</em>) is used as an indicator of rainfall magnitude. It is found that ignoring the effects of stress on soil hydraulic properties significantly underestimates the probability of failure (<em>p</em><sub>f</sub>) and associated risk of the slope. For <em>T</em> <span><math><mrow><mo>≥</mo></mrow></math></span> 50 years, this underestimation can reach up to 83% for <em>p</em><sub>f</sub> and be as much as 6.7 times for failure risk, especially at shorter rainfall durations. This highlights the significance of incorporating stress effects, as the increasing frequency of short-duration extreme rainfall events under climate change. Different criteria for determining damage states influence the development of fragility curves, but minor damage is predominant. Rainfall events with larger <em>T</em> (i.e., more extreme rainfall) cause higher probabilities of slope failure and damage, which become even greater with longer rainfall durations at the same <em>T</em>. However, these rainfall events must occur first for the effects to be realised. This indicates that, apart from focusing on extreme rainfall, attention should also be directed toward prolonged rainfall durations with relatively low intensity, as their high likelihood of occurrence can also increase the probabilities of slope failure and damage.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107992"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-16DOI: 10.1016/j.compgeo.2026.108000
Haichun Ma , Yanan Wang , Jiazhong Qian , Chenglong Xie , Zhitang Lu , Lei Ma
The theory of rock joint closure is a crucial research subject in rock mechanics. However, existing theoretical studies predominantly analyze contact processes between two rough surfaces, which has proven effective for studying joint stress and contact deformation. Yet this approach fails to adequately utilize relevant parameters to analyze stress-induced contact behavior, as both surfaces undergo geometric deformation. To address this, the equivalent theory is employed, transforming the interaction between two rough surfaces into that between a rough composite surface and a rigid plane. This method effectively describes the evolution of the composite surface during contact. Combining composite surface parameters with the boundary element method (BEM), the composite surface enables accurate elastoplastic simulation of joint stress variations by using conjugate gradient method. The roughness parameters of the composite surface can be more conveniently expressed relative to the two surfaces. The multi-peak structure of the composite surface reveals contact nuclei during joint closure, along with independent development and mutual fusion processes, while stress distribution from the nucleus center outward follows specific attenuation patterns. The composite surface model allows precise calculation of displacement at spatial points. The composite surface proposed in this study holds significant theoretical value for investigating joint deformation mechanisms.
{"title":"Key geometric surface of the normal rock joint deformation:Aperture into an equivalent rough composite surface based on BEM","authors":"Haichun Ma , Yanan Wang , Jiazhong Qian , Chenglong Xie , Zhitang Lu , Lei Ma","doi":"10.1016/j.compgeo.2026.108000","DOIUrl":"10.1016/j.compgeo.2026.108000","url":null,"abstract":"<div><div>The theory of rock joint closure is a crucial research subject in rock mechanics. However, existing theoretical studies predominantly analyze contact processes between two rough surfaces, which has proven effective for studying joint stress and contact deformation. Yet this approach fails to adequately utilize relevant parameters to analyze stress-induced contact behavior, as both surfaces undergo geometric deformation. To address this, the equivalent theory is employed, transforming the interaction between two rough surfaces into that between a rough composite surface and a rigid plane. This method effectively describes the evolution of the composite surface during contact. Combining composite surface parameters with the boundary element method (BEM), the composite surface enables accurate elastoplastic simulation of joint stress variations by using conjugate gradient method. The roughness parameters of the composite surface can be more conveniently expressed relative to the two surfaces. The multi-peak structure of the composite surface reveals contact nuclei during joint closure, along with independent development and mutual fusion processes, while stress distribution from the nucleus center outward follows specific attenuation patterns. The composite surface model allows precise calculation of displacement at spatial points. The composite surface proposed in this study holds significant theoretical value for investigating joint deformation mechanisms.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 108000"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-16DOI: 10.1016/j.compgeo.2026.107983
Zerui Zhang, Deqiong Kong, Shasha Ren, Bin Zhu
The reliable assessment of installation process, particularly concerning internal soil heave development and suction control, is crucial for the design of suction caissons. This paper presents a comprehensive investigation of the installation mechanisms in clay using large deformation sequential limit analysis. It reveals that suction installation fundamentally differs from jacking installation by consistently inducing inward soil flow, contrasting to the soil plug phenomenon. Furthermore, the presence of a caisson tip chamfer shows a negligible influence on suppressing soil heave during suction installation, suggesting that the application of design principles derived from jacking installation analyses may require re-evaluation. A critical finding concerns the role of interface roughness (α), which exhibits a significant and potentially underappreciated adverse effect: beyond the well-documented increase in installation resistance, a higher α markedly elevates the risk of promoting excessive soil heave (installation suction pressure us surpassing critical suction pressure uc) and installation refusal (us surpassing allowable suction pressure ua). Consequently, caisson design should prioritize reducing interface roughness, particularly at clayey sites with low soil strength gradients. Finally, explicit empirical models are developed to facilitate the evaluation of these key suction thresholds in engineering design.
{"title":"Large deformation numerical modelling of suction caisson installation in clay: Quantification of soil heave and suction control","authors":"Zerui Zhang, Deqiong Kong, Shasha Ren, Bin Zhu","doi":"10.1016/j.compgeo.2026.107983","DOIUrl":"10.1016/j.compgeo.2026.107983","url":null,"abstract":"<div><div>The reliable assessment of installation process, particularly concerning internal soil heave development and suction control, is crucial for the design of suction caissons. This paper presents a comprehensive investigation of the installation mechanisms in clay using large deformation sequential limit analysis. It reveals that suction installation fundamentally differs from jacking installation by consistently inducing inward soil flow, contrasting to the soil plug phenomenon. Furthermore, the presence of a caisson tip chamfer shows a negligible influence on suppressing soil heave during suction installation, suggesting that the application of design principles derived from jacking installation analyses may require re-evaluation. A critical finding concerns the role of interface roughness (<em>α</em>), which exhibits a significant and potentially underappreciated adverse effect: beyond the well-documented increase in installation resistance, a higher <em>α</em> markedly elevates the risk of promoting excessive soil heave (installation suction pressure <em>u</em><sub>s</sub> surpassing critical suction pressure <em>u</em><sub>c</sub>) and installation refusal (<em>u</em><sub>s</sub> surpassing allowable suction pressure <em>u</em><sub>a</sub>). Consequently, caisson design should prioritize reducing interface roughness, particularly at clayey sites with low soil strength gradients. Finally, explicit empirical models are developed to facilitate the evaluation of these key suction thresholds in engineering design.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107983"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-16DOI: 10.1016/j.compgeo.2026.107953
Hechen Zhou , Xiaoqiang Gu , Xiaomin Liang
Understanding the elastic incremental behavior and path-dependent shear stiffness of granular materials is essential for developing advanced constitutive models, yet their directional dependence under anisotropic conditions remains insufficiently quantified. This study adopted discrete element method (DEM) to simulate a series of probe tests on both spherical and clump particle assemblies under various stress states. Elastic incremental responses are systematically investigated under multiple loading directions and interpreted within a hyperelastic framework. The strain response envelopes exhibit centro-symmetric elliptical forms, from which a simple relation between the envelope rotation angle, the stiffness anisotropy parameter α and fabric anisotropy is established. The deviatoric strain demonstrates a distinct sinusoidal dependence on the loading direction, with its phase difference primarily governed by α. The results show that shear stiffness varies significantly across probing directions. A unified formulation is thus proposed to predict the normalized stiffness along arbitrary loading directions solely from α, showing an excellent agreement with DEM results across different particle geometries and stress states. This work quantitatively elucidates how anisotropy dictates directional shear stiffness and elastic strain envelopes, offering new insights into the anisotropic elasticity of granular materials.
{"title":"Deciphering the role of anisotropy in elastic incremental behavior and path-dependent shear stiffness of granular materials","authors":"Hechen Zhou , Xiaoqiang Gu , Xiaomin Liang","doi":"10.1016/j.compgeo.2026.107953","DOIUrl":"10.1016/j.compgeo.2026.107953","url":null,"abstract":"<div><div>Understanding the elastic incremental behavior and path-dependent shear stiffness of granular materials is essential for developing advanced constitutive models, yet their directional dependence under anisotropic conditions remains insufficiently quantified. This study adopted discrete element method (DEM) to simulate a series of probe tests on both spherical and clump particle assemblies under various stress states. Elastic incremental responses are systematically investigated under multiple loading directions and interpreted within a hyperelastic framework. The strain response envelopes exhibit centro-symmetric elliptical forms, from which a simple relation between the envelope rotation angle, the stiffness anisotropy parameter <em>α</em> and fabric anisotropy is established. The deviatoric strain demonstrates a distinct sinusoidal dependence on the loading direction, with its phase difference primarily governed by <em>α</em>. The results show that shear stiffness varies significantly across probing directions. A unified formulation is thus proposed to predict the normalized stiffness along arbitrary loading directions solely from <em>α</em>, showing an excellent agreement with DEM results across different particle geometries and stress states. This work quantitatively elucidates how anisotropy dictates directional shear stiffness and elastic strain envelopes, offering new insights into the anisotropic elasticity of granular materials.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107953"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-01DOI: 10.1016/j.compgeo.2026.107948
Xu Gao , Tian-Chyi Jim Yeh , E-Chuan Yan , Guo-qing Chen
Traditional displacement back analysis of the spatial distribution of hillslope mechanics parameters relies on costly and inefficient collections of displacement data from boreholes. This paper proposes a method that fuses monitored displacements at the hillslope surface after excavation and the vibration velocities after applying impact-loading to invert (back analysis) the spatial distribution of elastic modulus. Via numerical experiments, we demonstrate the effectiveness of the method and draw the following conclusion: if only excavation displacement at the hillslope surface is available for the back analysis, the resolution of the estimated elastic modulus field is too smooth. The inversion resolution of the elastic modulus field using the fusion of vibration velocities and excavation displacements on the hillslope surface is comparable to that of inversion using borehole displacement data. Moreover, the results of fusion back analysis also lead to accurate slope stability predictions. Further, the cross-correlation analysis reveals that the vibration velocity data contain more spatial heterogeneity characteristics of elastic modulus at different locations of the hillslope than the excavation displacement data. As the monitoring density of vibration velocity increases, the inversion resolution of the elastic modulus field initially improves and then stabilizes, suggesting that deploying monitoring points with a horizontal spacing of half of the horizontal spatial correlation scale is sufficient.
{"title":"Fusion of vibration velocity and excavation displacements for inversion of mechanical parameters of heterogeneous hillslope","authors":"Xu Gao , Tian-Chyi Jim Yeh , E-Chuan Yan , Guo-qing Chen","doi":"10.1016/j.compgeo.2026.107948","DOIUrl":"10.1016/j.compgeo.2026.107948","url":null,"abstract":"<div><div>Traditional displacement back analysis of the spatial distribution of hillslope mechanics parameters relies on costly and inefficient collections of displacement data from boreholes. This paper proposes a method that fuses monitored displacements at the hillslope surface after excavation and the vibration velocities after applying impact-loading to invert (back analysis) the spatial distribution of elastic modulus. Via numerical experiments, we demonstrate the effectiveness of the method and draw the following conclusion: if only excavation displacement at the hillslope surface is available for the back analysis, the resolution of the estimated elastic modulus field is too smooth. The inversion resolution of the elastic modulus field using the fusion of vibration velocities and excavation displacements on the hillslope surface is comparable to that of inversion using borehole displacement data. Moreover, the results of fusion back analysis also lead to accurate slope stability predictions. Further, the cross-correlation analysis reveals that the vibration velocity data contain more spatial heterogeneity characteristics of elastic modulus at different locations of the hillslope than the excavation displacement data. As the monitoring density of vibration velocity increases, the inversion resolution of the elastic modulus field initially improves and then stabilizes, suggesting that deploying monitoring points with a horizontal spacing of half of the horizontal spatial correlation scale is sufficient.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107948"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-04DOI: 10.1016/j.compgeo.2026.107952
Xinyi Wu, Jialin Xu, Chengshun Xu, Zhuolin Su
Solid-liquid two-phase flows with particles of a wide size range are widespread in geotechnical engineering. The CFD-DEM method is valid for solid–fluid coupling analysis, but traditional methods are limited in size applicability. This study proposes an improved semi-resolved CFD-DEM method capable of simulating systems with wide mesh/particle size ratios (L/d). In the method, a dynamic coupling strategy is adopted for different L/d: when the mesh size is much larger than the particle diameter, a gradient-based interpolation method is used to reconstruct the fluid velocity around the particles; when the mesh size is comparable to or smaller than the particle diameter, inter-phase forces are corrected through an extended domain. The proposed method is validated through the simulation of two typical cases, including single particle settling and collapse of granular piles, and is applied to upward seepage in sandy soils. Simulation results show that the method not only accurately reflects macroscopic phenomena, but also effectively captures the characteristics of the local flow field around particles in wide L/d systems, thereby revealing the mesoscopic mechanisms of particle–fluid interactions. Furthermore, the simulation of upward seepage indicated that the non-uniformity of the flow field drives the preferential migration of fine particles, which subsequently induces piping in gap-graded soils.
{"title":"An improved semi-resolved CFD-DEM method for particle systems with wide mesh/particle size ratios","authors":"Xinyi Wu, Jialin Xu, Chengshun Xu, Zhuolin Su","doi":"10.1016/j.compgeo.2026.107952","DOIUrl":"10.1016/j.compgeo.2026.107952","url":null,"abstract":"<div><div>Solid-liquid two-phase flows with particles of a wide size range are widespread in geotechnical engineering. The CFD-DEM method is valid for solid–fluid coupling analysis, but traditional methods are limited in size applicability. This study proposes an improved semi-resolved CFD-DEM method capable of simulating systems with wide mesh/particle size ratios (<em>L</em>/<em>d</em>). In the method, a dynamic coupling strategy is adopted for different <em>L</em>/<em>d</em>: when the mesh size is much larger than the particle diameter, a gradient-based interpolation method is used to reconstruct the fluid velocity around the particles; when the mesh size is comparable to or smaller than the particle diameter, inter-phase forces are corrected through an extended domain. The proposed method is validated through the simulation of two typical cases, including single particle settling and collapse of granular piles, and is applied to upward seepage in sandy soils. Simulation results show that the method not only accurately reflects macroscopic phenomena, but also effectively captures the characteristics of the local flow field around particles in wide <em>L</em>/<em>d</em> systems, thereby revealing the mesoscopic mechanisms of particle–fluid interactions. Furthermore, the simulation of upward seepage indicated that the non-uniformity of the flow field drives the preferential migration of fine particles, which subsequently induces piping in gap-graded soils.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"193 ","pages":"Article 107952"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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