Yanghui Shi, Huaxiang Yan, Hongqiang Dou, Qiao Wang, Ziheng Wang
An alternative structure with an up‐gradient permeable reactive barrier (PRB) and a down‐gradient cut‐off wall is proposed to enhance plume capture and degradation while optimizing material use. A 2D analytical model is developed to predict the contaminant transport through the dual‐domain barrier system. The proposed analytical solutions are verified by comparing their predictions with results from numerical solutions and from previously published 1D analytical model. The derived analytical solution is used to explore how the arrangement of PRB and cut‐off wall structures affects the system's performance. We show that the cut‐off wall domain can direct flow and reduce the contaminant flux through the system due to its low permeability. The system performance can be best improved with the decrease of the contaminant half‐life in PRB, whereas the impact of the PRB retardation factor on the system performance is less important due to the quick saturation of the adsorption for the PRB material. The average flux through the total system can be decreased to 5.4 × 10 −4 mg·m −2 ·s −1 (3.7 times lower than the limited value) when the contaminant half‐life in PRB is 1 h. Additionally, the pumping/recharge wells are suggested to be together used to control the contaminant flow velocity since high equivalent head losses can lead to poor remediation efficiency of the system. The proposed alternative PRB structure and analytical solution are expected to be effective tools for the management and remediation of the organic contaminated sites.
{"title":"Analytical Study on the Performance of a Novel Barrier: Cut‐Off Wall and Permeable Reactive Barrier Dual‐Domain System","authors":"Yanghui Shi, Huaxiang Yan, Hongqiang Dou, Qiao Wang, Ziheng Wang","doi":"10.1002/nag.70225","DOIUrl":"https://doi.org/10.1002/nag.70225","url":null,"abstract":"An alternative structure with an up‐gradient permeable reactive barrier (PRB) and a down‐gradient cut‐off wall is proposed to enhance plume capture and degradation while optimizing material use. A 2D analytical model is developed to predict the contaminant transport through the dual‐domain barrier system. The proposed analytical solutions are verified by comparing their predictions with results from numerical solutions and from previously published 1D analytical model. The derived analytical solution is used to explore how the arrangement of PRB and cut‐off wall structures affects the system's performance. We show that the cut‐off wall domain can direct flow and reduce the contaminant flux through the system due to its low permeability. The system performance can be best improved with the decrease of the contaminant half‐life in PRB, whereas the impact of the PRB retardation factor on the system performance is less important due to the quick saturation of the adsorption for the PRB material. The average flux through the total system can be decreased to 5.4 × 10 <jats:sup>−4</jats:sup> mg·m <jats:sup>−2</jats:sup> ·s <jats:sup>−1</jats:sup> (3.7 times lower than the limited value) when the contaminant half‐life in PRB is 1 h. Additionally, the pumping/recharge wells are suggested to be together used to control the contaminant flow velocity since high equivalent head losses can lead to poor remediation efficiency of the system. The proposed alternative PRB structure and analytical solution are expected to be effective tools for the management and remediation of the organic contaminated sites.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"269 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chaojia Liu, Xiaolei Chong, Lei Liang, Zhenglei Chen, Yan Li
Based on wheel‐soil interaction theory and numerical methods, this study first analyzes the stress distribution characteristics of soil runway structures under aircraft wheel loads: A 5% increase in compaction degree leads to an approximate 20% rise in stress at the contact center. It is also confirmed that stress distribution in high‐compaction soil runways is dominated by vertical stress, while horizontal stress plays a more prominent role in softer soils. Through decoupling analysis, the formation and evolution mechanism of soil runway ruts is clarified, and a comprehensive rut depth prediction model integrating compaction degree, tire inflation pressure, wheel load, and passing times is proposed. Additionally, this study investigates the influencing factors of rolling resistance on soil runways, revealing that wheel load exerts the most significant effect. Finally, validation against field test results shows a numerical calculation error of approximately 7%–8%. These findings can effectively predict aircraft trafficability on soil runways, providing critical references for assessing the safety and adaptability of such runways.
{"title":"Multi‐Method Analysis of Wheel‐Soil Interaction Mechanics: Integrating Experimental and Computational Insights for Aircraft Performance on Soil Runways","authors":"Chaojia Liu, Xiaolei Chong, Lei Liang, Zhenglei Chen, Yan Li","doi":"10.1002/nag.70227","DOIUrl":"https://doi.org/10.1002/nag.70227","url":null,"abstract":"Based on wheel‐soil interaction theory and numerical methods, this study first analyzes the stress distribution characteristics of soil runway structures under aircraft wheel loads: A 5% increase in compaction degree leads to an approximate 20% rise in stress at the contact center. It is also confirmed that stress distribution in high‐compaction soil runways is dominated by vertical stress, while horizontal stress plays a more prominent role in softer soils. Through decoupling analysis, the formation and evolution mechanism of soil runway ruts is clarified, and a comprehensive rut depth prediction model integrating compaction degree, tire inflation pressure, wheel load, and passing times is proposed. Additionally, this study investigates the influencing factors of rolling resistance on soil runways, revealing that wheel load exerts the most significant effect. Finally, validation against field test results shows a numerical calculation error of approximately 7%–8%. These findings can effectively predict aircraft trafficability on soil runways, providing critical references for assessing the safety and adaptability of such runways.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"40 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shijiang Pu, Shunchuan Wu, Haiyong Cheng, Gai Kui, Shigui Huang, Yifan Cao
The complexity of joint structures creates substantial uncertainty in determining the mechanical parameters of tunnel surrounding rock, while traditional experimental methods fail to adequately represent actual engineering conditions. To improve the accuracy of rock mass mechanical parameter identification and strengthen the scientific foundation of support design, this study performs a statistical analysis of working face joints using the CAE Sirovision three‐dimensional rock surface scanning system. The combined discrete fracture network (DFN) and discrete element method (DEM) are used to reconstruct the joint distribution network, thereby establishing a high‐precision numerical analysis framework. Based on this framework, a BTO‐BiTCN‐BiGRU‐Attention hybrid inversion model for determining joint mechanical parameters is proposed. The inversion results are then incorporated into DFN–DEM simulations to derive the mechanical parameters of the rock mass and evaluate the deformation characteristics of the surrounding rock. The results indicate that the proposed inversion model outperforms traditional neural network and ensemble learning approaches in prediction accuracy, with a displacement error between calculated and measured values remaining below 7%. The integration of accurately characterized joint distributions and mechanical parameters offers robust data support for tunnel support design and strengthens its scientific rationale.
{"title":"Acquisition of Rock Mass Mechanical Parameters and Analysis of Surrounding Rock Deformation Characteristics in Jointed Rock Mass Tunnels","authors":"Shijiang Pu, Shunchuan Wu, Haiyong Cheng, Gai Kui, Shigui Huang, Yifan Cao","doi":"10.1002/nag.70210","DOIUrl":"https://doi.org/10.1002/nag.70210","url":null,"abstract":"The complexity of joint structures creates substantial uncertainty in determining the mechanical parameters of tunnel surrounding rock, while traditional experimental methods fail to adequately represent actual engineering conditions. To improve the accuracy of rock mass mechanical parameter identification and strengthen the scientific foundation of support design, this study performs a statistical analysis of working face joints using the CAE Sirovision three‐dimensional rock surface scanning system. The combined discrete fracture network (DFN) and discrete element method (DEM) are used to reconstruct the joint distribution network, thereby establishing a high‐precision numerical analysis framework. Based on this framework, a BTO‐BiTCN‐BiGRU‐Attention hybrid inversion model for determining joint mechanical parameters is proposed. The inversion results are then incorporated into DFN–DEM simulations to derive the mechanical parameters of the rock mass and evaluate the deformation characteristics of the surrounding rock. The results indicate that the proposed inversion model outperforms traditional neural network and ensemble learning approaches in prediction accuracy, with a displacement error between calculated and measured values remaining below 7%. The integration of accurately characterized joint distributions and mechanical parameters offers robust data support for tunnel support design and strengthens its scientific rationale.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"40 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haoran Jin, Dechun Lu, Zhiwei Gao, Xin Zhou, Xiuli Du
A systematic study on the non‐orthogonal plastic flow of sand is conducted using discrete element modelling, where particles representing the shapes of Toyoura sand are used, enabling the quantitative prediction of material behaviour in triaxial compression. The direction of plastic strain increment obtained by stress probing is analysed with respect to the normal to memory surfaces, which are determined based on a newly developed method. Within the memory surface, the plastic strain increment is small and follows the direction of stress increment. When the stress state is on the memory surface, sand has much lower stiffness, and the plastic strain increment is controlled by both the current stress state and stress increment. A non‐orthogonal flow rule for predicting the maximum plastic strain increment direction is evaluated. The underlying mechanism for non‐orthogonal flow of sand is analysed by comparing with the plastic response of metal. A bounding surface framework for modelling the full stress‐strain relationship is presented.
{"title":"Micromechanical Analysis and Theoretical Modelling of Non‐Orthogonal Plastic Flow for Sand","authors":"Haoran Jin, Dechun Lu, Zhiwei Gao, Xin Zhou, Xiuli Du","doi":"10.1002/nag.70228","DOIUrl":"https://doi.org/10.1002/nag.70228","url":null,"abstract":"A systematic study on the non‐orthogonal plastic flow of sand is conducted using discrete element modelling, where particles representing the shapes of Toyoura sand are used, enabling the quantitative prediction of material behaviour in triaxial compression. The direction of plastic strain increment obtained by stress probing is analysed with respect to the normal to memory surfaces, which are determined based on a newly developed method. Within the memory surface, the plastic strain increment is small and follows the direction of stress increment. When the stress state is on the memory surface, sand has much lower stiffness, and the plastic strain increment is controlled by both the current stress state and stress increment. A non‐orthogonal flow rule for predicting the maximum plastic strain increment direction is evaluated. The underlying mechanism for non‐orthogonal flow of sand is analysed by comparing with the plastic response of metal. A bounding surface framework for modelling the full stress‐strain relationship is presented.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"15 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shield tunneling beneath an existing tunnel can significantly impact the safety and stability of the existing tunnel. A clear understanding of the response of the existing tunnel subjected to underpassing shield tunneling is therefore essential for maintaining its operational safety. In view of this, this study proposes a coupling analytical method to investigate the behavior of an existing tunnel subjected to underpassing shield tunneling. First, the vertical free displacement corresponding to the existing tunnel position is determined using the virtual image method, and the additional vertical displacement of the existing tunnel is derived through tunnel–soil displacement coupling analysis. The corresponding bending moment and shear force in the existing tunnel are subsequently obtained by differentiating its displacement profile. The validity of the proposed method is demonstrated through two engineering case studies, and the results show good agreement not only with field observations but also with numerical simulations and results from other analytical approaches. Results from the parametric analysis reveal that increasing the bending stiffness of the existing tunnel reduces its maximum displacement while simultaneously amplifies the maximum bending moment and shear force. Moreover, the bending moment of the existing tunnel increases linearly with the gap parameter, while increasing both the intersection angle and the vertical clearance between the existing and shield tunnels effectively mitigates its maximum displacement. The proposed analytical method provides a valuable tool for predicting the response of existing tunnel subjected to underpassing shield tunneling.
{"title":"Coupling Analytical Investigation on the Response of an Existing Tunnel Subjected to Underpassing Shield Tunneling","authors":"Kai Zhang, Zelin Zhou, Zhiyi Wan, Xiangyu Han, Heng Zhang, Junsong Liang, Shougen Chen","doi":"10.1002/nag.70221","DOIUrl":"https://doi.org/10.1002/nag.70221","url":null,"abstract":"Shield tunneling beneath an existing tunnel can significantly impact the safety and stability of the existing tunnel. A clear understanding of the response of the existing tunnel subjected to underpassing shield tunneling is therefore essential for maintaining its operational safety. In view of this, this study proposes a coupling analytical method to investigate the behavior of an existing tunnel subjected to underpassing shield tunneling. First, the vertical free displacement corresponding to the existing tunnel position is determined using the virtual image method, and the additional vertical displacement of the existing tunnel is derived through tunnel–soil displacement coupling analysis. The corresponding bending moment and shear force in the existing tunnel are subsequently obtained by differentiating its displacement profile. The validity of the proposed method is demonstrated through two engineering case studies, and the results show good agreement not only with field observations but also with numerical simulations and results from other analytical approaches. Results from the parametric analysis reveal that increasing the bending stiffness of the existing tunnel reduces its maximum displacement while simultaneously amplifies the maximum bending moment and shear force. Moreover, the bending moment of the existing tunnel increases linearly with the gap parameter, while increasing both the intersection angle and the vertical clearance between the existing and shield tunnels effectively mitigates its maximum displacement. The proposed analytical method provides a valuable tool for predicting the response of existing tunnel subjected to underpassing shield tunneling.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"44 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Layered unsaturated soils are a prevalent form of shallow soils, and their consolidation process is pretty complex due to the interaction of three phases, including solid, water, and air. In practical ground improvement projects, sand drain techniques are commonly employed to accelerate the consolidation rate in the horizontal direction. Therefore, the consolidation process cannot be simplified as a one‐dimensional problem. This study established a two‐dimensional consolidation analysis system for layered unsaturated soil media, considering the flow of both pore water and pore air, as well as the continuity conditions between unsaturated soil layers. Subsequently, the static equilibrium equations and the constitutive equations for unsaturated soils are incorporated into the system to obtain the deformation distribution at any point within the unsaturated soil media over time. A novel solution to this system is derived based on the transformed differential quadrature method by combining the Laplace integral transform technique and differential quadrature rules, where the former is employed to address the time‐dependent partial differential terms, and the latter is utilized to discretize the spatial domain. The inverse Laplace transform is then conducted to obtain the solution in the physical domain. The proposed solution is validated by comparing the results with existing analytical solutions. Furthermore, the effects of permeability coefficients, mechanical properties of the unsaturated soil interlayer, and the horizontal spacing of sand drains on the two‐dimensional consolidation behavior of layered unsaturated soil media are analyzed.
{"title":"A Two‐Dimensional Transformed Differential Quadrature Solution for Air‐Hydro‐Mechanical Coupling in Layered Unsaturated Soils","authors":"Huanjia Kou, Zhenming Shi, Yong Zhi Zhao, Junliang Li, Qing Wang","doi":"10.1002/nag.70202","DOIUrl":"https://doi.org/10.1002/nag.70202","url":null,"abstract":"Layered unsaturated soils are a prevalent form of shallow soils, and their consolidation process is pretty complex due to the interaction of three phases, including solid, water, and air. In practical ground improvement projects, sand drain techniques are commonly employed to accelerate the consolidation rate in the horizontal direction. Therefore, the consolidation process cannot be simplified as a one‐dimensional problem. This study established a two‐dimensional consolidation analysis system for layered unsaturated soil media, considering the flow of both pore water and pore air, as well as the continuity conditions between unsaturated soil layers. Subsequently, the static equilibrium equations and the constitutive equations for unsaturated soils are incorporated into the system to obtain the deformation distribution at any point within the unsaturated soil media over time. A novel solution to this system is derived based on the transformed differential quadrature method by combining the Laplace integral transform technique and differential quadrature rules, where the former is employed to address the time‐dependent partial differential terms, and the latter is utilized to discretize the spatial domain. The inverse Laplace transform is then conducted to obtain the solution in the physical domain. The proposed solution is validated by comparing the results with existing analytical solutions. Furthermore, the effects of permeability coefficients, mechanical properties of the unsaturated soil interlayer, and the horizontal spacing of sand drains on the two‐dimensional consolidation behavior of layered unsaturated soil media are analyzed.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"8 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145844810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanan Pirunjinda, Pornkasem Jongpradist, Hyung‐Mok Kim, Dong‐Woo Ryu, Pitthaya Jamsawang, Chana Phutthananon
Reliable prediction of final settlement and practical risk assessment are essential for the economic design of large‐scale land reclamation projects. While stochastic analysis offers valuable insights into soil spatial variability, the critical issue of large‐scale statistical heterogeneity has been overlooked in most previous work. Given that reclamation is typically conducted over extensive areas, the statistical parameters of soil properties are unlikely to be uniform across the entire site. This study highlights these local spatial effects and presents a novel stochastic analysis approach to account for them in final settlement and risk evaluations for a reclaimed area. Clustering analysis reveals two distinct zone types within the study area: a region exhibiting well‐clustered borehole data and another characterized by dispersed, non‐clusterable data. For the former, considering statistical parameters from the clustered area in the stochastic analysis yields a more economical and safer risk assessment. For the latter, a safe design is ensured by adopting the parameter set, whether global or from an overlapping zone, with the highest coefficient of variation in the compression index. The findings indicate that overlooking these critical local effects by using only global statistical parameters can result in a design that is either less safe or unnecessarily costly.
{"title":"Stochastic Risk Analysis of Settlement in Large‐Filled Areas Considering the Local Spatial Effect of Soil Properties","authors":"Sanan Pirunjinda, Pornkasem Jongpradist, Hyung‐Mok Kim, Dong‐Woo Ryu, Pitthaya Jamsawang, Chana Phutthananon","doi":"10.1002/nag.70216","DOIUrl":"https://doi.org/10.1002/nag.70216","url":null,"abstract":"Reliable prediction of final settlement and practical risk assessment are essential for the economic design of large‐scale land reclamation projects. While stochastic analysis offers valuable insights into soil spatial variability, the critical issue of large‐scale statistical heterogeneity has been overlooked in most previous work. Given that reclamation is typically conducted over extensive areas, the statistical parameters of soil properties are unlikely to be uniform across the entire site. This study highlights these local spatial effects and presents a novel stochastic analysis approach to account for them in final settlement and risk evaluations for a reclaimed area. Clustering analysis reveals two distinct zone types within the study area: a region exhibiting well‐clustered borehole data and another characterized by dispersed, non‐clusterable data. For the former, considering statistical parameters from the clustered area in the stochastic analysis yields a more economical and safer risk assessment. For the latter, a safe design is ensured by adopting the parameter set, whether global or from an overlapping zone, with the highest coefficient of variation in the compression index. The findings indicate that overlooking these critical local effects by using only global statistical parameters can result in a design that is either less safe or unnecessarily costly.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"47 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145844809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhandong Su, Kunze Li, Mingdong Zang, Zhigang Tao, Qian Yin, Hong Wang, Fei Gan, Yao Niu, Xianxiu Lu
Understanding fault activation and slip is vital for earthquake mechanics and underground structure stability. Fault stability, beyond in situ stresses, depends on their architecture, including asperities, segments, and gouge materials. This study investigates locked fault segments of varying lengths using mortar specimens with prefabricated faults filled with montmorillonite and quartz sand gouge. Uniaxial loading was applied, with embedded strain gauges and digital image speckle techniques monitoring internal stress, surface strain, and displacement near the fault. Results show increased model strength with longer locked segments. Local stress field deflection angles vary more in the dilatation quadrant than the compression quadrant. Gouge material disperses stress concentrations during loading. Slip occurs along the structural surface during failure, with the relative sliding rate of blocks correlating strongly with stress field deflection angle changes. As the system transitions from elastic to stable fracture stages, this correlation in the dilatation quadrant shifts. These findings offer insights into complex fault mechanisms and stability compared to simple planar saw‐cut discontinuities.
{"title":"Impact of Locked Segments in Laboratory Activated Faults: Insights From Near‐Field Strain Monitoring in Analog Rock Materials Under Uniaxial Stress","authors":"Zhandong Su, Kunze Li, Mingdong Zang, Zhigang Tao, Qian Yin, Hong Wang, Fei Gan, Yao Niu, Xianxiu Lu","doi":"10.1002/nag.70219","DOIUrl":"https://doi.org/10.1002/nag.70219","url":null,"abstract":"Understanding fault activation and slip is vital for earthquake mechanics and underground structure stability. Fault stability, beyond in situ stresses, depends on their architecture, including asperities, segments, and gouge materials. This study investigates locked fault segments of varying lengths using mortar specimens with prefabricated faults filled with montmorillonite and quartz sand gouge. Uniaxial loading was applied, with embedded strain gauges and digital image speckle techniques monitoring internal stress, surface strain, and displacement near the fault. Results show increased model strength with longer locked segments. Local stress field deflection angles vary more in the dilatation quadrant than the compression quadrant. Gouge material disperses stress concentrations during loading. Slip occurs along the structural surface during failure, with the relative sliding rate of blocks correlating strongly with stress field deflection angle changes. As the system transitions from elastic to stable fracture stages, this correlation in the dilatation quadrant shifts. These findings offer insights into complex fault mechanisms and stability compared to simple planar saw‐cut discontinuities.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"12 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145812849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ayoub Aqazddammou, Tikou Belem, Safa Chlahbi, Ahmed Camile, Abdessamad Khalil
This study investigates tunnel stability within sedimentary rock masses characterized by multiple joint sets and challenging geological conditions. The behavior of stratified rock masses around an excavation depends on both the intact rock and the combination of dominant and bedding joints. The main objective of this study is to highlight the convergence and deformation in rock masses around horseshoe‐shaped tunnels using an integrated methodology that combines field investigations, finite element modeling, and pull‐out test results. Statistical analysis confirmed the robustness of the 3D modeling approach for reproducing in situ behavior and creating realistic models of heterogeneous, anisotropic rock masses. The numerical results indicate that the highest displacement ratio is concentrated at the intersection of the bedding and dominant joints with dip angles ranging from 0° to 45°, which should be considered as critical dip angles for mining progress. Indeed, wedge and sliding failure zones developed on the roofs and left rib, respectively. Increasing depth reduced the influence of rock mass quality, particularly for GSI chart values ranging between 35 and 40, resulting in significant convergence around the excavation. The support system emphasizes the effectiveness of systematic bolting in competent rock masses. Moreover, the pull‐out tests revealed that the load‐bearing capacity of the split‐set bolts increased substantially when the bedding approached vertical orientations θ = 90°, and the compressive strength exceeded 39.6 MPa, conditions that promote safer tunneling through vertical stratum orientations. These findings enhance the understanding of tunneling stability mechanisms in stratified rock masses with multiple joint sets under various geological conditions.
{"title":"Experimental and Numerical Investigation of the Effect of Rock Mass Behavior and Stratum Orientations on Horseshoe‐Shaped Tunnel Stability","authors":"Ayoub Aqazddammou, Tikou Belem, Safa Chlahbi, Ahmed Camile, Abdessamad Khalil","doi":"10.1002/nag.70217","DOIUrl":"https://doi.org/10.1002/nag.70217","url":null,"abstract":"This study investigates tunnel stability within sedimentary rock masses characterized by multiple joint sets and challenging geological conditions. The behavior of stratified rock masses around an excavation depends on both the intact rock and the combination of dominant and bedding joints. The main objective of this study is to highlight the convergence and deformation in rock masses around horseshoe‐shaped tunnels using an integrated methodology that combines field investigations, finite element modeling, and pull‐out test results. Statistical analysis confirmed the robustness of the 3D modeling approach for reproducing in situ behavior and creating realistic models of heterogeneous, anisotropic rock masses. The numerical results indicate that the highest displacement ratio is concentrated at the intersection of the bedding and dominant joints with dip angles ranging from 0° to 45°, which should be considered as critical dip angles for mining progress. Indeed, wedge and sliding failure zones developed on the roofs and left rib, respectively. Increasing depth reduced the influence of rock mass quality, particularly for GSI <jats:sub>chart</jats:sub> values ranging between 35 and 40, resulting in significant convergence around the excavation. The support system emphasizes the effectiveness of systematic bolting in competent rock masses. Moreover, the pull‐out tests revealed that the load‐bearing capacity of the split‐set bolts increased substantially when the bedding approached vertical orientations θ = 90°, and the compressive strength exceeded 39.6 MPa, conditions that promote safer tunneling through vertical stratum orientations. These findings enhance the understanding of tunneling stability mechanisms in stratified rock masses with multiple joint sets under various geological conditions.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"11 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145812850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accurate calibration of discrete element simulation parameters (characteristic parameters) for unstructured pavements is a prerequisite for model application, particularly in analyses such as tire-pavement contact mechanics. Focusing on soil pavements, experiments such as the soil angle of repose were conducted, using the angle of repose as the response value. A fusion screening method for significant characteristic parameters of unstructured pavements was proposed using Plackett–Burman experiments, the Spearman correlation coefficient, and the gradient boosting decision tree algorithm (GBDT). The steepest ascent experiment determined the optimal range of the significant characteristic parameters, and a polynomial kernel-based support vector regression (poly-SVR) model was introduced to obtain their optimal values. Based on this, a discrete element model for the unstructured pavement was established, and its validity was demonstrated through compaction tests. Results showed an average relative error of 0.55% between simulated and measured soil repose angles, demonstrating the feasibility of the significant characteristic parameter fusion screening method and the poly-SVR model for identifying optimal parameter values. Additionally, the mean relative error between the measured and simulated soil compaction values was determined to be 7.40%, confirming the validity of the established pavement model. The presented calibration method for discrete element simulation parameters of unstructured pavements can serve as a theoretical reference for related research.
{"title":"Parameter Calibration of Discrete Element Simulation for Unstructured Pavements Using Method-Fused Screening and a Polynomial Kernel-Based Support Vector Regression Model","authors":"Maoping Ran, Maosheng Hua, Shenqing Xiao, Jing Zhou, Yuqi Liu, Xinglin Zhou","doi":"10.1002/nag.70169","DOIUrl":"10.1002/nag.70169","url":null,"abstract":"<div>\u0000 \u0000 <p>Accurate calibration of discrete element simulation parameters (characteristic parameters) for unstructured pavements is a prerequisite for model application, particularly in analyses such as tire-pavement contact mechanics. Focusing on soil pavements, experiments such as the soil angle of repose were conducted, using the angle of repose as the response value. A fusion screening method for significant characteristic parameters of unstructured pavements was proposed using Plackett–Burman experiments, the Spearman correlation coefficient, and the gradient boosting decision tree algorithm (GBDT). The steepest ascent experiment determined the optimal range of the significant characteristic parameters, and a polynomial kernel-based support vector regression (poly-SVR) model was introduced to obtain their optimal values. Based on this, a discrete element model for the unstructured pavement was established, and its validity was demonstrated through compaction tests. Results showed an average relative error of 0.55% between simulated and measured soil repose angles, demonstrating the feasibility of the significant characteristic parameter fusion screening method and the poly-SVR model for identifying optimal parameter values. Additionally, the mean relative error between the measured and simulated soil compaction values was determined to be 7.40%, confirming the validity of the established pavement model. The presented calibration method for discrete element simulation parameters of unstructured pavements can serve as a theoretical reference for related research.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 4","pages":"2094-2107"},"PeriodicalIF":3.6,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145807662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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