{"title":"Stability Analysis of Slope Subjected to Seepage Forces Considering Spatial Variability of Soil Properties","authors":"Mário Vargas Ceron, Diogo Lira Cecílio, Renato Vaz Linn, Samir Maghous","doi":"10.1002/nag.3993","DOIUrl":"https://doi.org/10.1002/nag.3993","url":null,"abstract":"The stability analysis of a saturated soil slope subjected to seepage flow generated by rapid water level drawdown is investigated in this paper by means of the limit analysis kinematic approach. The analysis takes into account the inherent spatial variability of soil strength and permeability properties. Adopting the framework of effective stresses for formulating the strength failure condition of the saturated porous medium, it is shown that the effect of seepage flow can be accounted for in the stability analysis by means of driving body forces computed from the gradient of pore pressure distribution. The hydraulic boundary value problem governing the water filtration velocity is addressed by resorting to a specific analytical variational approach, whose accuracy is assessed through comparison with finite element solutions. The impact of hydraulic‐related parameters on the slope stability is first investigated within a deterministic framework. In the probabilistic stability analysis, soil cohesion, friction angle, and permeability are modeled as random fields that are numerically generated, making use of the Karhenum–Loéve Expansion. The Monte Carlo simulation method has been employed to evaluate the probability density function of the slope stability factor as well as associated overall failure probability. Numerical analyses have been performed with the aim to investigate the impact of some statistical parameters defining the distributions of strength and permeability on the slope stability conditions. Comparison of the simulation results with available numerical predictions pointed out the ability of the proposed stochastic limit analysis approach to accurately address the slope stability problem.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"23 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889836","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}
{"title":"Semi‐Analytical Solution for Passive Earth Pressure in Unsaturated Narrow Soils Behind Retaining Walls With a Log‐Spiral Failure Surface Based on the Principal Stress Trajectory Method","authors":"Bo Deng, Wei Long, Zhenyu He, Yufan Gao","doi":"10.1002/nag.3995","DOIUrl":"https://doi.org/10.1002/nag.3995","url":null,"abstract":"Most existing passive earth pressure theories are not completely suitable for the calculation of unsaturated backfill in practical engineering, especially for narrow backfill cases. In view of this, this study establishes a modified analytical model for the passive earth pressure of narrow backfill behind a retaining wall under unsaturated steady‐state seepage conditions, based on the log‐spiral failure mechanism and the arched differential element method. The distribution, total force magnitude, and the height of the application point of passive earth pressure for narrow backfill under the rotation about the wall toe (RB) mode are calculated by the fourth order Runge–Kutta method within the framework of the generalized effective stress principle. To validate the proposed method, a comparative analysis is conducted by integrating experimental, theoretical, and OptumG2 simulation results. Moreover, the effect of main parameters on passive earth pressures is investigated through a parametric analysis. The results show that as the wall–soil interface friction angle increases gradually, the passive earth pressure distribution curve transitions from convex towards the wall back to concave towards the wall back; with the increase of aspect ratio, the passive earth pressure curve gradually shifts from curved to nearly straight; with a small air entry pressure parameter, the total passive earth pressure force increases as the air entry pressure parameter increases, while the height of the application point of total force initially decreases and then increases; the hysteresis effect reduces the total passive earth pressure force and decreases the height of the application point of the total force.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"8 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875989","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}
Shangqu Sun, Zhibin Jiang, Liping Li, Jing Wang, Shuguang Song
{"title":"DEM Analysis on Rock‐Breaking Impact Effect of Shield Disc Cutter in Typical Soft and Hard Composite Strata","authors":"Shangqu Sun, Zhibin Jiang, Liping Li, Jing Wang, Shuguang Song","doi":"10.1002/nag.3991","DOIUrl":"https://doi.org/10.1002/nag.3991","url":null,"abstract":"During shield tunneling in composite strata, the disc cutter's abnormal damage rate rises sharply under interface impact, due to strata inhomogeneity. This study investigates the dynamic response and the cause of the peak impact force of disc cutters at soft‐hard rock interfaces using the discrete element method. Simulations of linear cutting processes under varying interfacial bonding strengths were conducted to compare the dynamic response characteristics of the disc cutter in soft rock, hard rock, and interfacial zones. Through the failure characteristics of the composite rock and the law of crack propagation, the influence of the rock damage evolution on cutter loading states was analyzed, thereby elucidating the origins of force variations experienced by disc cutters at interfacial zones. The results show that lithological differences disrupt the continuity of the dense rock core at the interface. The weakened interfacial bonding strength redirects crack propagation, delaying failure initiation in the soft rock near the interface. The stress attenuation across the interfacial transition zone reduces damage accumulation in the hard rock, enhancing rock‐breaking resistance of the hard rock against the cutter during interface crossing. When the disc cutter transitions into the hard rock stratum, the normal force reaches a peak magnitude. At the interface, the normal force increases by 34% compared to the homogeneous hard rock zone. The research clarifies the mechanism of disc cutter impact at the interface, providing a reference for alleviating abnormal damage induced by interfacial effects.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"6 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875987","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}
{"title":"Multiscale and Multifield Investigation on Soil Leakage at the Diaphragm Wall Opening During Excavation","authors":"Yajing Liu, Chenglong Jiang, Lingling Zeng, Zhangbo Wan, Xuanyu Cheng","doi":"10.1002/nag.3983","DOIUrl":"https://doi.org/10.1002/nag.3983","url":null,"abstract":"Opening in diaphragm wall is a primary cause of water and sand leakage in excavation, often leading to severe excavation accidents. This process involves complex interactions between fluid flow, granular soil around openings, and continuum materials, yet there is a lack of appropriate calculation methods to address it. This study develops a multiscale, multifield calculation framework integrating the discrete element method (DEM), computational fluid dynamics (CFD), and finite difference method (FDM) to address the challenges of large deformation and fluid‐soil interaction caused by through‐wall leakage in excavation. A numerical model is developed based on a relevant case of retaining wall leakage, analyzing the effects of leakage depth, surcharge load, and water head. The study reveals that soil leakage at the diaphragm wall opening is driven by both geostress and fluid forces. As strain energy release from stress relief increases with leakage depth, it accelerates soil particle movement, resulting in greater soil loss at deeper levels. However, the soil arching effect at deeper levels limits the stress relief zone, reducing the influence area and mitigating the adverse effects of soil leakage. Additionally, while surcharge load behind the diaphragm wall has minimal impact on cumulative soil loss at the opening, it significantly increases ground settlement and wall deflection.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"24 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875988","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}
{"title":"Unraveling the Microscopic Mechanics of Kaolinite‐Hematite Interfaces in Granite Residual Soil With MD/DFT","authors":"Senlin Li, Jinsong Shen, Xiongying Ma, Xin Kang, Renpeng Chen","doi":"10.1002/nag.3992","DOIUrl":"https://doi.org/10.1002/nag.3992","url":null,"abstract":"Granite residual soils exhibit exceptional shear strength despite their water sensitivity. This behavior likely results from cemented aggregates, where free iron oxides act as cementing agents for clay minerals. The limitations of traditional experimental techniques hinder direct verification of the hypothesized microscopic stabilization mechanism, which relies on interfacial bonding between free iron oxides and clay minerals. To overcome this challenge, we leverage state‐of‐the‐art molecular dynamics (MD) and density functional theory (DFT) simulations to investigate complex interactions and mechanical characteristics at the interface consisting of kaolinite (001) and hematite (001) surfaces. Simulation results demonstrate that kaolinite (001) and hematite (001) surfaces tend to evolve toward energy minimization, forming a highly stable and adhesive kaolinite (001)‐hematite (001) interface through hydrogen bonding and Fe–O ionic bonds. Exceptionally, this interface exhibits dual stick‐slip friction behavior due to the misalignment of center atoms in Fe–O and Al–O octahedra and the shear–rebound deformation of hematite. Moreover, the interface frictional force exhibits a linear relationship with the normal load, while the microscopic friction angle and cohesion demonstrate a dependence on sliding velocity, which is in contrast to Amonton's law. This research unveils the microscopic underpinnings of stable aggregate formation in granite residual soil and offers a novel perspective on the intricate interplay between these components, ultimately elucidating the mechanical behavior of these aggregates.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"27 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872733","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}
{"title":"Parameterized Local Reduced Order Model of Stimulated Volume Evolution in Reservoirs","authors":"Saeed Hatefi Ardakani, Robert Gracie","doi":"10.1002/nag.3988","DOIUrl":"https://doi.org/10.1002/nag.3988","url":null,"abstract":"Real‐time simulation of large‐scale geomechanics problems, such as hydraulic dilation stimulation, is computationally expensive as they must span multiple spatial and temporal length scales, often including nonlinearities and thermo‐hydromechanical processes. This paper introduces a novel local reduced order model (LROM) to enhance computational efficiency for nonlinear and fully‐coupled hydromechanical simulations. The model employs finite element analysis of a two‐dimensional deformable porous media with Drucker–Prager plasticity and stress‐induced permeability enhancement models to describe behavior of sandstone. LROM combines various reduced order models (ROMs), including proper orthogonal decomposition‐Galerkin (POD‐G) to reduce number of degrees of freedom (DoFs), discrete empirical interpolation method (DEIM) to accelerate computation of nonlinear terms, and local POD and local DEIM (LPOD/LDEIM) for further performance enhancements. LPOD and LDEIM classify parameterized training data, obtained from offline coupled full order model (CFOM) runs, into multiple subspaces with similar dynamic features. A new strategy for clustering and classification techniques that align with coupled formulation framework is proposed. The advantages of LROM are demonstrated in a large‐scale application: hydraulic dilation stimulation. LROM exhibits stable, accurate, and efficient online phase, while ROM built with classical POD/DEIM lacks efficiency and stability in Newton–Raphson solver. First, performance of LROM, parameterized by hardening modulus and initial permeability, is evaluated for inputs within training domain. Under CFOMs with DoFs, LROM speed‐up is 400 times. LROM is then parameterized by three inputs, including injection rate and two material properties. Results show that LROM maintains efficiency even for injection rates that extend beyond the training regime.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"33 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862130","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}
{"title":"Numerical Model for Granular Flow With Interstitial Fluid","authors":"Yadong Wang, Wei Wu","doi":"10.1002/nag.3990","DOIUrl":"https://doi.org/10.1002/nag.3990","url":null,"abstract":"We present a constitutive model for the mechanical behavior of granular flow for both solid‐like and fluid‐like regimes. The stress rate tensor is decomposed into rate‐independent and rate‐dependent parts. The hypoplastic model is used for the rate‐independent part, while the ‐type rheological model is employed for the rate‐dependent part. The Stokes number is introduced to capture the influence of interstitial fluid viscosity within the rate‐dependent part of the model. The model performance is demonstrated through numerical simulations of element tests, encompassing both granular materials and granular‐fluid mixtures.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"52 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857503","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}
{"title":"Feasibility Experiment and Simulation on Controlling the “Pot Cover Effect” of Subgrade in Seasonally Frozen Regions by Capillary Barrier Layer","authors":"Mingli Zhang, Ruiling Zhang, Yaling Chou, Peilin Zhao, Wei Feng, Duoyu Mi","doi":"10.1002/nag.3985","DOIUrl":"https://doi.org/10.1002/nag.3985","url":null,"abstract":"The pot cover effect can increase the moisture content in shallow soil, which reduces subgrade strength and may lead to engineering issues, such as pavement cracks and deformation. Therefore, studying the prevention measures for the subgrade pot cover effect is essential. This paper proposes preventive measures, inspired by capillary barrier layers used in landfills, that involve installing such layers to mitigate the subgrade pot cover effect. First, a self‐designed test device was used to compare the hydrothermal changes in conventional fill subgrade and subgrade with gravel and sand capillary barrier layer in a seasonal frozen soil environment. Second, a water–vapor–heat coupling model was developed to simulate the quantitative changes in water migration induced by the capillary barrier layer during the experiment. Finally, the long‐term effect of using a capillary barrier layer to mitigate the pot cover effect on a loess subgrade in northwest China was simulated. The results show that at a depth of 2.5 cm, the liquid water content without a capillary barrier increases with the number of freeze–thaw cycles, reaching a maximum increase of 5.9%. In contrast, the maximum increase in liquid water content at the same depth in the soil layer with a capillary barrier is only 0.9%; the water vapor flux of the subgrade with a capillary barrier layer is 1/10 of that of the subgrade without a capillary barrier layer. The proposed capillary barrier layer method offers theoretical insights for mitigating the pot cover effect and guiding future subgrade designs.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"108 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853337","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}
{"title":"Group Effects of Energy Pipe Piles Embedded in Layered Transversely Isotropic Soils Due to Thermo‐Mechanical Loading","authors":"Zhi Yong Ai, Lei Xu, Jia Ming Ye, Li‐Min Zhang","doi":"10.1002/nag.3989","DOIUrl":"https://doi.org/10.1002/nag.3989","url":null,"abstract":"Energy pile technology is an environmentally sustainable and economically viable solution to achieve building thermal comfort. Energy pipe piles offer advantages over solid piles due to their inner hollow space, allowing for the installation of heat exchange tubes and optimization of backfill materials. Although the activation of an energy pile group can significantly promote the heat exchange performance for satisfying the energy demand of upper structures, there is currently no efficient calculation method available for the energy pipe pile group. Hence, this paper utilizes the coupled boundary element‐finite element method to investigate behaviors of energy pipe pile groups embedded in layered transversely isotropic soils, aiming to guide optimal design and accelerate application promotion. The proposed method's validity is confirmed through field tests and finite element simulations. Parametric analyses indicate that the reduction of pile thickness weakens the group effect, and the induced tensile forces in pipe piles under cooling conditions should be paid more attention when the pile spacing is large and the soil is stiff. Besides, a stiff bearing stratum minimizes the overall settlement and facilitates the uniform axial force distribution within energy pipe pile groups.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"28 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847059","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}
Yingbin Liu, Shaoming Liao, Yaowen Yang, Junzuo He
{"title":"Torsional Behaviors of Segmental Tunnels Under the Action of Shield Rolling and Jack Thrusting During Tunneling","authors":"Yingbin Liu, Shaoming Liao, Yaowen Yang, Junzuo He","doi":"10.1002/nag.3987","DOIUrl":"https://doi.org/10.1002/nag.3987","url":null,"abstract":"The large torque generated by the rotary disk potentially causes the rolling of shield/tunnel boring machine (TBM), especially when it cuts rocks with over‐excavation or hard obstacles in very soft stratum, which further induces the torsion of assembled segments. In addition, the segment torsion may accumulate due to the unidirectional rotary cutting of shield/TBM over long distances. Excessive torsion of a tunnel induces track inclination, segment cracking, and bolt shearing failure. In the paper, a torsional shield‐lining on grouted foundation model was proposed to investigate the torsional behaviors of a segmental tunnel under the action of shield rolling and jack thrusting during tunneling. The segmental tunnel is regarded as a beam with reduced torsional stiffness, subjected to three‐dimensional foundation reactions and force boundary constrained by the shield. Besides, a grouted foundation model with longitudinal variable stiffness, accounting for the effect of grout solidification, was applied. The torque transferred from the rotary disk on segments was discussed, and the method to determine the longitudinal torsional stiffness of the segmental tunnel was introduced, considering the effect of shield rolling and jack thrusting. The proposed model was verified by two case studies, and a parametric analysis was conducted to investigate the effects of torque and the characteristics of grout material on structural responses. Additionally, the cumulative torsion of segments subjected to the unidirectional cutting of the shield was discussed. The proposed model and analytical results prove a valuable reference for tunnel anti‐torsion design and control measures of segment assembly.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"16 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841328","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}