International Journal for Numerical and Analytical Methods in Geomechanics最新文献

{"title":"A Comprehensive Investigation of Particle Gradation Effects on Limiting Void Ratios and Pore Structures of Granular Soils","authors":"Meng Fan, Ning Zhang, Dong Su, Wenjie Deng, Rui‐Xiao Zhang, Guo‐Jun Cai, Xiang‐Sheng Chen","doi":"10.1002/nag.70318","DOIUrl":"https://doi.org/10.1002/nag.70318","url":null,"abstract":"The limiting void ratios (i.e., maximum and minimum void ratios, <jats:italic>e</jats:italic> <jats:sub>max</jats:sub> and <jats:italic>e</jats:italic> <jats:sub>min</jats:sub> ) and pore structures of granular soils critically influence their compactness, permeability, and deformation behavior. However, the effects of particle gradation on both macroscopic limiting void ratios and microscopic pore structures remain inadequately quantified. In this study, DEM simulations of the loosest and densest packings of ideal spheres are conducted to isolate gradation effects from particle shape. The combined influences of the coefficient of uniformity ( <jats:italic> C <jats:sub>u</jats:sub> </jats:italic> ) and coefficient of curvature ( <jats:italic> C <jats:sub>c</jats:sub> </jats:italic> ) on limiting void ratios are systematically investigated, and predictive models are developed to accurately capture these effects, with both interpolation accuracy and extrapolation capability validated. Additionally, particle gradation effects on three‐dimensional pore structures are analyzed, revealing that pore size distributions are well described by the Weibull distribution. Predictive models linking Weibull parameters to gradation parameters are also proposed, demonstrating high accuracy across a wide range of gradations. These findings provide quantitative tools for predicting both macroscopic limiting void ratios and pore‐scale properties from particle gradation, offering valuable insights for geotechnical design and optimization.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"16 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655893","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":"Study on Water-Rock Coupling Damage Mechanism and Water Inrush Prevention and Control of Overlying Coal Seam in Karst Confined Aquifer in Karst Area","authors":"Jiabao Liu,&nbsp;Guiyi Wu,&nbsp;Dezhong Kong,&nbsp;Fuxing Mei,&nbsp;Gaofeng Song,&nbsp;Yujun Zuo,&nbsp;Qingzhi Liu","doi":"10.1002/nag.70265","DOIUrl":"10.1002/nag.70265","url":null,"abstract":"<div>\u0000 \u0000 <p>To solve limestone floor water inrush and reduce accidents, this paper studies Fengxianglin Coal Mine. It uses field investigation, mechanical experiments, similar simulation and engineering numerical simulation to explore limestone floor damage, Maokou Formation fracture development, and the influence of advancing distance, coal seam burial depth, aquitard thickness and floor water pressure on floor water inrush during coal—seam mining above confined water. Results show that stress—strain curves of limestone with different water content have four stages: initial stress growth, crack compaction, stress increase and stress drop. Water dissolution softens limestone, enhances nonlinear deformation and changes failure mode from local brittle to overall plastic. The coupling of pore water pressure and mining stress reduces floor strata strength and raises water inrush risk. Digital image correlation (DIC) technology monitoring shows that in the process of working face advancing. The maximum principal strain concentration range and degree of strata gradually expand. The strain distribution is ‘W’ shape, and the displacement curve is irregular ‘M’ shape. Water inrush occurs when the floor damage zone connects with the aquifer water channel. Numerical simulation reveals that increasing advancing distance raises floor fractures and pore pressure. Pore pressure distribution changes from inverted ‘circular arch’ to inverted ‘concave’ with increasing coal seam burial depth. Increasing aquitard thickness reduces pore pressure and inhibits fracture propagation. Increasing floor water pressure accelerates crack propagation and heightens water inrush risk.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2928-2953"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122033","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":"Active Earth Pressure From Unsaturated Soils With Displacement Modes of Rigid Retaining Wall Under Rainfall Conditions","authors":"Lei Zhang,&nbsp;Xin Jiang,&nbsp;Rong Sun,&nbsp;Canyang Cui,&nbsp;Jianbiao Du,&nbsp;Hanyan Gu,&nbsp;Yanjun Qiu","doi":"10.1002/nag.70256","DOIUrl":"10.1002/nag.70256","url":null,"abstract":"<div>\u0000 \u0000 <p>This study proposes a unified analytical framework for unsaturated active earth pressure to evaluate retaining wall stability under transient rainfall infiltration. The framework incorporates three critical wall displacement modes: translation (T), rotation about the top (RT), and rotation about the base (RB). Guided by finite element analyses that systematically characterize the evolution of principal stress trajectories and failure surface morphologies under each mode, an analytical solution is derived. This solution integrates an extended Mohr-Coulomb strength criterion, a generalized wetting front infiltration model, and an inclined-slice limit equilibrium approach featuring an interlayer shear coefficient to quantify inter-slice shear forces. Experimental and numerical validations confirm the method's reliability. Parametric studies demonstrate that a deepening wetting front increases the lateral active earth pressure and the overturning moment on the retaining wall, thereby significantly reducing stability. The applicability of the resultant force acting at one-third of the wall height is governed by the combined effects of wall displacement modes, soil matric suction, slope inclination, and wall-soil interface friction angle. This methodology establishes a theoretically rigorous yet practical tool for stability assessment under extreme rainfall events, offering crucial insights for engineering design optimization.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2835-2854"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122039","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":"Insights Into the Mechanisms Controlling the Residual Strength of Bio-cemented Sands","authors":"Aoxi Zhang,&nbsp;Frédéric Collin,&nbsp;Antoine Wautier,&nbsp;Anne-Catherine Dieudonné","doi":"10.1002/nag.70239","DOIUrl":"10.1002/nag.70239","url":null,"abstract":"<p>Microbially induced carbonate precipitation (MICP) is an emerging technique for enhancing the mechanical properties of granular soils. Although several experimental studies have reported increased shear strength in MICP-treated soils at both peak and residual states, other findings have shown reductions in residual strength compared to untreated soils. This study uses the discrete element method (DEM) to investigate the mechanisms governing the residual strength of bio-cemented sands. The results indicate that residual strength may decrease when carbonate precipitates in the form of grain-bridging patterns. In that case, the introduction of carbonates alters the contact network and may induce metastable configurations, particularly when the bonds are weak or non-cohesive. These configurations are prone to strain localisation upon shearing, leading to the development of shear bands and a reduction in residual strength. Conversely, higher cohesive strength enhances microstructural stability, offsetting the weakening effects of localisation. The residual strength of bio-cemented sands is therefore governed by two competing mechanisms, namely bond-induced stabilisation and instability-driven localisation.</p>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2711-2726"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/nag.70239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Peridynamic Framework for Modeling Progressive Failure in Porous Sandstone Indentation","authors":"Sahir N. Butt,&nbsp;Jörg Renner,&nbsp;Günther Meschke","doi":"10.1002/nag.70241","DOIUrl":"10.1002/nag.70241","url":null,"abstract":"<p>A state-based peridynamic model is proposed to simulate the failure mechanisms in porous rocks, using Bentheim sandstone as a specific example. Experimental observations reveal a transition from brittle to ductile failure under increasing triaxial compression. This behavior is attributed to pore compaction. The peridynamic model is enhanced to capture the strain hardening observed in hydrostatic compression experiments and calibrated to reproduce pore-collapse behavior. Rock heterogeneity is incorporated through Weibull-distributed strength parameters, reflecting the stochastic nature of material properties. Simulations of indentation tests for four specimen sizes demonstrate the predictive capability of the model. A qualitative validation is established through acoustic emission data, while a quantitative validation relies on the comparison of numerical force–penetration and indentation pressure–penetration relationships with experimental results. Beyond reproducing macroscopic force responses, the model captures the spatiotemporal evolution of the compaction zone, and an energy-based analysis shows that grain comminution prior to failure contributes significantly to the total energy dissipation.</p>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2727-2743"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/nag.70241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and Analytical Studies on Increasing Near-Fault Fracture Stiffness to Control Induced Seismicity Based on an Equivalent Continuum Modelling Approach","authors":"Mingwei Gang,&nbsp;Atsushi Sainoki,&nbsp;Jun-ichi Kodama,&nbsp;Lishuai Jiang,&nbsp;Hani Mitri,&nbsp;Adam K. Schwartzkopff","doi":"10.1002/nag.70218","DOIUrl":"10.1002/nag.70218","url":null,"abstract":"<div>\u0000 \u0000 <p>The frequency and magnitude of induced seismicity have been increasing in recent times. Induced seismicity can cause significant damage to underground workings and therefore has become a major global issue. Hence, it is necessary to assess and mitigate the associated risks of induced seismicity. Previously, various methods have been implemented to minimise the hazards of induced seismicity to underground workings. However, their effectiveness is limited due to the inherent heterogeneity of the stress state within natural geological structures. This can result in unexpectedly large seismic events in distant regions away from anthropogenic activities, such as ore extraction and fluid injection/production. Hence, the present study aims to develop a novel method to control the intensity of induced seismicity by increasing the stiffness of the fault damage zone surrounding the fault core. In the present study, the effect of increasing fracture stiffness in the damage zone on seismic source parameters is investigated. First, the validity of the proposed method is assessed through an analytical study by evaluating energy released from a seismic event whilst assuming linear slip-weakening behaviour. Then, a mine-wide numerical model is constructed that can reproduce a complex and heterogeneous stress state within the fault damage zone by computing and applying equivalent compliance tensors to each element in the model, based on a discrete fracture network composed of millions of fractures. A parametric study is subsequently carried out to quantitatively analyse the effect of fracture stiffnesses under distinct fault zone cases: (a) different near-fault fracture densities, (b) different fracture dips, (c) different dip directions, (d) different depths, (e) different distances from fault core and (f) different initial stiffnesses. The results indicate that fracture stiffness significantly affects all the seismic source parameters in most cases. When the fracture stiffness is increased by a factor of five, the seismic source parameters are decreased to approximately 40%–50%. This result was found to closely align with that derived from the analytical study. However, its effectiveness becomes less significant with decreasing fracture densities, with seismic source parameters reduced only to 50%–75%, compared to approximately 40% under higher-density conditions. Furthermore, the seismic source parameters remain almost unchanged with increasing distance from the fault core. These results suggest that increasing fracture stiffness within a severely fractured rock mass in the vicinity of the fault core can effectively mitigate seismic hazards. This work may provide a foundation for future implementation of increasing fracture stiffness as a means of reducing seismic risk.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2691-2710"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146070419","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":"Supporting Stress Analysis of Pre-Tensioned Rock Bolts in Tunnels Considering the Effects of Installation Angles","authors":"Hongtao Wang,&nbsp;Mingzhu Zhao,&nbsp;Ping Liu,&nbsp;Xiaojing Li,&nbsp;Yunjuan Chen","doi":"10.1002/nag.70248","DOIUrl":"10.1002/nag.70248","url":null,"abstract":"<div>\u0000 \u0000 <p>Rock bolts are commonly used to stabilize surrounding rocks in deep underground excavations, such as mines, tunnels, and underground caves. In actual underground projects, it is common to form an oblique angle between the installed rock bolt and the surrounding rock surface, owing to the design parameters, construction quality, or rough excavation contour. Currently, studies on the mechanical characteristics of inclined rock bolts remain relatively limited. In this study, non-fully anchored rock bolts are investigated, and an analytical model is presented for the surrounding rock supported by a bolt installed at any angle. In this model, the supporting effect produced by the rock bolt on the surrounding rock was considered to originate from the interfacial adhesion at the anchored part and uniform pressure at the bolt plate. Theoretical analytical solutions for the bolt stress and supporting stress within the surrounding rock were derived by applying elasticity theory to the model. The effectiveness of the proposed theoretical method was verified by comparing it with numerical simulations and experimental test results from previous studies. The effects of the bolt angle, pretension force, anchor length, deployment pattern, and rock parameters on the supporting stress distribution characteristics of the surrounding rock were analyzed. For the first time, this study determines the support effect of inclined rock bolts and provides a theoretical basis for the optimization of bolt deployment and the selection of support parameters in tunnels.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2744-2770"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071597","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":"Effect of Particle Size on Stick-Slip Dynamics of Shear Bands Considering Randomness of Initial Particle Positions in Discrete Element Modeling","authors":"Wenping Gong,&nbsp;Wei Xiong,&nbsp;Shaoyan Zhang,&nbsp;Huiming Tang,&nbsp;Lei Wang,&nbsp;Ying Zhao","doi":"10.1002/nag.70249","DOIUrl":"10.1002/nag.70249","url":null,"abstract":"<div>\u0000 \u0000 <p>Stick-slip dynamics of shear bands is vital to the evolution of geological hazards such as earthquakes and landslides. Extensive studies have been conducted to analyze the effect of the particle geometry on the stick-slip dynamics. However, the impact of the initial positions of these particles has rarely been studied. With the aid of discrete element method modeling, the influence of particle size on the stick-slip dynamics is revisited, with particular emphasis on initial particle positions. The initial particle positions in this study are sampled with Monte Carlo simulations. The results illustrate that a shear band with larger particles tends to exhibit fewer stick-slip events, longer recurrence time, and more evident friction drop. The stick-slip dynamics is strongly affected by initial particle positions, and the effects increase with the particle size. Parameteric analyses indicate that these effects could only be slightly influenced by the contact models of the particles, model parameters, boundary conditions, and model dimensions. These findings provide new insights into the stick-slip dynamics and emphasize how the initial particle positions influence the stick-slip dynamics of faults and earthquakes.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2790-2805"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122421","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":"Simplified Prediction Method for Ground Surface Displacement Caused by Full‐Process Excavation of Quasi‐Rectangular Shield Tunnels","authors":"Yongjie Qi, Gang Wei, Haibo Jiang, Jian Zhou, Zhiguo Zhang","doi":"10.1002/nag.70316","DOIUrl":"https://doi.org/10.1002/nag.70316","url":null,"abstract":"In order to explore the surface displacement law caused by the entire process of rectangular shield tunneling, the effects of the additional cutterhead thrust ( <jats:italic>p</jats:italic> <jats:sub>1</jats:sub> ) of the cutterhead, the shield shell friction ( <jats:italic>p</jats:italic> <jats:sub>2</jats:sub> ), the additional grouting pressure ( <jats:italic>p</jats:italic> <jats:sub>3</jats:sub> ) at the tail of the shield, and ground loss caused by the quasi‐rectangular shield tunneling were considered. The traditional integration method for the above four factors was simplified, and a simplified calculation method for surface displacement values was proposed. Based on the Zhengzhou Metro Line 8 project, the surface displacement values caused by each factor were calculated. The simplified method calculation values were compared and verified with the integration method calculation values and measured data. The influence of parameter changes on the accuracy of displacement calculation values and simplified methods was further analyzed. The results show that the surface displacement values calculated by the simplified method are in good agreement with the values calculated by the integral method and the measured data. The Poisson's ratio of soil ( <jats:italic>μ</jats:italic> ), the internal friction angle ( <jats:italic>φ</jats:italic> ), and the depth‐to‐diameter ratio ( <jats:italic>H</jats:italic> <jats:sub>d</jats:sub> ) are the main parameters that affect the accuracy of the simplified method. The conditions that need to be met to control the calculation error of surface displacement within 5%, 10%, and 20% are given, and the applicable working conditions of the simplified method are summarized.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"28 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655890","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":"Fracture Mechanism and Energy Dissipation Characteristics of Coal-Rock Composite Anchored Body With Through-Going Joints","authors":"Xue-kui Xin,&nbsp;Qing-bin Meng,&nbsp;Xiang-hui Zhang","doi":"10.1002/nag.70264","DOIUrl":"10.1002/nag.70264","url":null,"abstract":"<div>\u0000 \u0000 <p>Based on uniaxial and triaxial compression tests of coal and sandstone, deformation and strength parameters for the coal-rock-bolt composite structure were determined, providing key inputs for subsequent single free-surface loading simulation. A numerical model characterizing coal-rock composite anchored body with through-going joints was developed using FLAC^3D 9.0 integrated with Fish scripting language. By developing a real-time energy density tracking program, multi-factor coupled simulation loading experiments were systematically conducted. The simulations reveal the strength parameter degradation and energy evolution law of the anchored bodies of the coal-rock composite with through-going joints. Results indicate that the ultimate strength of the coal-rock combination depends on the coal mass, the plastic deformation capacity relies more on the rock mass, with the overall stiffness exhibiting intermediate characteristics between coal and rock. Both peak strength and energy storage limits demonstrate positive correlations with interfacial roughness. Furthermore, for the composite geological bodies formed by coal and rock, anchoring reinforcement applied to weaker zones effectively coordinates stress and energy distribution within the composite structure, suppressing localized damage propagation, thereby increasing the energy storage threshold and delaying the catastrophic failure time of the anchored body. Therefore, a “weakness-compensation-first” support strategy is proposed to enhance the overall geomechanical performance of the composite structure.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"50 6","pages":"2903-2927"},"PeriodicalIF":3.6,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122035","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}