Computers and Geotechnics最新文献

{"title":"Thermodynamics-based bounding surface model for gas hydrate-bearing sediments and its numerical implementation","authors":"Zengchun Sun ,&nbsp;Yue Peng ,&nbsp;Haoqi Song ,&nbsp;Hao Cui ,&nbsp;Minqiang Meng ,&nbsp;Henghui Fan","doi":"10.1016/j.compgeo.2025.107242","DOIUrl":"10.1016/j.compgeo.2025.107242","url":null,"abstract":"<div><div>In-depth research on the mechanical properties and constitutive models of gas hydrate-bearing sediments (GHBSs) is fundamental for achieving efficient hydrate exploration and geological disaster prevention. In the current study, a bounding surface model for GHBSs is developed based on the principle of thermodynamics. By choosing an appropriate dissipation function and free energy function, a yield surface function containing three shape parameters can be obtained. Considering the filling and bonding effects of hydrates, and introducing the hydrate strength evolution parameter, a thermodynamics-based bounding surface model for GHBSs is established using a non-associated flow rule. Then, the explicit substeping scheme with error control is implemented to develop a UMAT subroutine for the proposed model and integrated into the ABAQUS. Compared with the drained monotonic triaxial shear data indicates that the proposed model can adequately capture the shear behaviors of sandy, silty sandy, and clay-silty GHBSs under different stress levels and saturations. In addition, the model demonstrates good applicability and feasibility in undrained cyclic triaxial shear tests and boundary value problem analysis.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107242"},"PeriodicalIF":5.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760252","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}

{"title":"A meshless numerical method for optimised design of buried structures in elastic medium","authors":"Hassan Liravi ,&nbsp;Javad Fakhraei ,&nbsp;Sakdirat Kaewunruen ,&nbsp;Zhuojia Fu ,&nbsp;Jelena Ninić","doi":"10.1016/j.compgeo.2025.107222","DOIUrl":"10.1016/j.compgeo.2025.107222","url":null,"abstract":"<div><div>Performance-based design is critical to examine how changes in design parameters influence the safety and stability of the examined structural systems, ensuring optimised performance under varying conditions. Traditional approaches such as finite element method, require careful domain meshing and mesh-sensitivity studies, which are often computationally expensive and, in some cases, mathematically challenging for certain types of problems. Meshless approaches provide efficient and accurate prediction models to address this problem effectively. In this paper, a two-dimensional singular boundary method combined with the method of fundamental solutions is formulated in conjunction with the direct differentiation method to perform design sensitivity-based optimisation of structures embedded in elastic medium under harmonic point loads. The proposed formulation is employed to overcome the non-uniqueness solution problem arising in the singular boundary method when dealing with exterior elastic problems. The accuracy and effectiveness of the proposed approach is assessed in the framework of two analytical examples: a cylindrical cavity subjected to pulsating pressure under Neumann boundary condition and a cavity with a five-cusped hypocycloid boundary under Dirichlet boundary condition. Additionally, the method is assessed in an application of a horseshoe-shaped tunnel embedded in full-space medium and subjected to Neumann boundary conditions. The results indicate that the proposed approach is both accurate and robust for performing sensitivity analysis on complex geometries in elastic media, particularly when compared to the classical singular boundary method. Furthermore, the application case study demonstrates that the method can be effectively used for optimising the shape of underground structures to minimise the impact of geometry on deformations of the surrounding soil. This methodology offers several advantages: it is truly meshless, integration-free, mathematically simple, and easy to implement, providing a valuable tool for decision-making in the design of buried structures within elastic media.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107222"},"PeriodicalIF":5.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Assessing direct CPT-based methods for predicting pile base resistance using coupled DEM-FDM simulations","authors":"Fei Chai ,&nbsp;Bo Liu ,&nbsp;Jianfeng Xue ,&nbsp;Kevin Duffy","doi":"10.1016/j.compgeo.2025.107230","DOIUrl":"10.1016/j.compgeo.2025.107230","url":null,"abstract":"<div><div>This study utilises parallel discrete element method (DEM) simulations of cone penetration tests (CPTs) and pile load tests to investigate the application of direct CPT-based methods for predicting the base capacity of bored piles in layered soils. To reduce boundary effects, a coupled DEM-finite difference method (FDM) model is constructed to simulate pile load tests. The study focuses on the scale effect of pile diameter on the correction factor <em>α</em>_b and the effectiveness of existing <em>q</em>_c averaging methods in layered soils. Two pile diameters and three soil layering conditions, featuring a single silt layer interbedded within sand at varying depths, are considered in the simulations. Results show that both soil layering and pile displacement influence the scale effect. At small settlements (<em>s</em>) up to 0.3 times the pile diameter (<em>D</em>), the scale effect is insignificant, except when a soft layer is directly above the pile tip. At larger settlements, particularly when <em>s</em> &gt; 0.5<em>D</em>, piles with smaller diameters show more pronounced reductions in base resistance due to a weak layer closely beneath the tip. Among the four methods evaluated, the BD-18 <em>q</em>_c averaging method produces more consistent <em>α</em>_b values across various soil profiles and pile diameters. Microscopic analysis reveals that soils above the tip contribute less to the pile base resistance at <em>s</em>/<em>D</em> = 0.1 than to the cone tip resistance. Additionally, the strength mobilisation levels of soils in most soil layering conditions appear similar at <em>s</em>/<em>D</em> = 0.1, supporting the proposal of a constant <em>α</em>_b value in direct CPT-based methods.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107230"},"PeriodicalIF":5.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747651","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}

{"title":"Semi-analytical elastic-viscoplastic solution for dynamic spherical cavity expansion in undrained clay considering rate and dynamic effects","authors":"Xinhai Zhang ,&nbsp;Lizhong Wang ,&nbsp;Yi Hong ,&nbsp;Shuzhao Li","doi":"10.1016/j.compgeo.2025.107209","DOIUrl":"10.1016/j.compgeo.2025.107209","url":null,"abstract":"<div><div>The phenomenon of dynamic cavity expansion is ubiquitous in engineering applications such as vibratory pile driving, dynamically installed anchors, and dynamic penetration tests. Dynamic resistance encompasses contributions from elastoplasticity, viscosity (or rate effect), and dynamic effects due to the inertia induced by accelerating surrounding soil. Existing solutions for cavity expansion in clay predominantly focuses on resistance from elastoplasticity, with a few paid to additionally consider either rate or dynamic effect. To date, there is still a lack of solution that can simulate dynamic penetration resistance into clay considering all the three effects. This study presents a semi-analytical model that integrates elastoplasticity, viscosity (or rate effect) and dynamic effects. This integration is achieved by incorporating an elastic-viscoplastic constitutive model (strain rate-dependent) into the general framework of spherical cavity expansion theory, coupled with the dynamic stress equilibrium equation to simulate dynamic effects. The proposed semi-analytical solution for dynamic spherical cavity expansion is validated by comparing its degenerate form with published quasi-static and dynamic solutions for the modified Cam-Clay (MCC) model. A comprehensive numerical parametric study is conducted to quantify and analyze the contributions of rate and dynamic effects. The results reveal three distinct velocity ranges: low, medium, and high-velocity. In the low-velocity range ((V_c/<em>a</em> &lt; 1), the strain rate effect rapidly intensifies, while the dynamic effect remains negligible. In the medium-velocity range (1 &lt; V_c/<em>a</em> &lt; 25), the limit cavity pressure primarily comprises elastic–plastic deformation and strain rate effects, with the dynamic effect starts to play a role. In the high-velocity range (V_c/<em>a</em> &gt; 25), the dynamic effect’s contribution becomes much more dominating, potentially exceeding 20 % at an expansion rate of 100. Regarding spatial distribution, the dynamic effect influences broader ranges of the surrounding soil than the strain rate effect.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107209"},"PeriodicalIF":5.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747653","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}

{"title":"Investigation on tunnel face failure under varying seepage conditions in saturated sand using coupled CFD-DEM and analytical modelling","authors":"Junzuo He ,&nbsp;Shaoming Liao ,&nbsp;Chao Liu ,&nbsp;Hai Liu ,&nbsp;Jie Cui ,&nbsp;Yingbin Liu","doi":"10.1016/j.compgeo.2025.107232","DOIUrl":"10.1016/j.compgeo.2025.107232","url":null,"abstract":"<div><div>Tunnels are increasingly being constructed in saturated sandy ground with high hydraulic head and permeability. However, limited attention has been given to face stability under various seepage conditions, which is critical for the safety of shield tunneling. To address this gap, a computational fluid dynamics-discrete element method (CFD-DEM) model was developed to simulate face failure under tunnel face seepage (TFS). The validated numerical model unveils that the specific discharge decreases exponentially with the increase of distance away from the tunnel face, but the increase of maximum specific discharge at tunnel face <em>q</em>_face,max can expand this influence range from 0.5<em>D</em> to 2<em>D</em>. Due to the seepage force directed toward the tunnel face, tunnel face unloading induces a loosening zone with a shape of wedge and inverted frustum shape, where the inclination angle decreases as <em>q</em>_face,max increases. Meanwhile, although the pressure afforded by the tunnel face can be alleviated by the soil arching effect, the TFS can weaken the soil arching effect and raise the limit support pressure (LSP). Based on the numerical results, the distribution of seepage force was derived and introduced into an equilibrium analysis. Thereby, an innovative analytical model for the estimation of LSP under TFS was proposed and verified. Additionally, the parametric study on the analytical model indicates that the pore pressure on the tunnel face center is inversely proportional to <em>q</em>_face,max, with the decreasing ratio negatively correlated to the void ratio <em>e</em> and the spherical seepage reduction factor <em>η</em>₀. Moreover, the LSP is positively correlated with <em>q</em>_face,max, <em>e,</em> and <em>C</em>, and negatively correlated with <em>η</em>₀ and internal friction angle.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107232"},"PeriodicalIF":5.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747652","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}

{"title":"Two-point MPM study of fluidized grains in internal erosion around metro tunnel characterized by an erosion law","authors":"Tianxin Qin ,&nbsp;Zhu Song ,&nbsp;Chen Wang ,&nbsp;Fayun Liang","doi":"10.1016/j.compgeo.2025.107227","DOIUrl":"10.1016/j.compgeo.2025.107227","url":null,"abstract":"<div><div>Groundwater infiltration through openings in tunnel linings can lead to the migration of fine soil particles from the coarse particle framework due to seepage forces known as internal erosion. However, current numerical methods face limitations in capturing the key process of the fluidization of fine particles surrounding tunnel linings within acceptable computational costs. To address these challenges, we introduce an erosion law into the two-point material point method where (i) the initiation of the fluidization of fine particles is based on the relative velocity between the solid and fluid phases and (ii) the fluidized soil mass is transferred to the fluid phase and migrated by the seepage force. After the verification of the present method, the internal erosion due to tunnel leakage is analyzed, with parametric analyses of the initial fine particle content, groundwater level, internal friction angle, and opening location. The results indicate that internal erosion accelerates the soil loss during tunnel seepage, highlighting the need for significant attention regarding this issue.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107227"},"PeriodicalIF":5.3,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725390","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}

{"title":"Seismic bearing capacity of foundations incorporating excess pore water pressure generation during an earthquake","authors":"Jyant Kumar,&nbsp;Sudipto Mukherjee","doi":"10.1016/j.compgeo.2025.107226","DOIUrl":"10.1016/j.compgeo.2025.107226","url":null,"abstract":"<div><div>Considering the occurrence of an earthquake, the bearing capacity of a strip footing placed on a saturated cohesive-frictional soil mass has been computed by performing a pseudo-static rigorous analysis incorporating the existence of (i) excess pore water pressures, and (ii) additional seismic- tractions and body forces. The analysis has been carried out by using lower and upper bounds finite elements limit analysis (FELA) in conjunction with the second order cone programming (SOCP) using the Mohr-Coulomb (MC) yield criterion. The generation of the excess pore water pressure in the event of an earthquake has been incorporated by defining a pore pressure coefficient <span><math><msub><mi>r</mi><mi>u</mi></msub></math></span> − a ratio of the excess pore water pressure to the total vertical overburden stress at any point. The analysis has revealed that the bearing capacity reduces considerably with an increase in the magnitude of horizontal earthquake acceleration. For a given magnitude of earthquake acceleration, the bearing capacity reduces extensively further with an increase in the value of <em>r</em>_u. All the computational results have been presented in a non-dimensional manner, and for the validation purpose, necessary comparisons have also been made. The study will be useful for designing foundations in a seismically active zone.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107226"},"PeriodicalIF":5.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714893","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}

{"title":"Predicting steady-state seepage flow in complex half-space using a modified scaled boundary finite element method","authors":"Chuhao Huang ,&nbsp;Jun Liu ,&nbsp;Zhiqiang Hu ,&nbsp;Lei Xiong ,&nbsp;Zhi Liu ,&nbsp;Lei Gan ,&nbsp;Wenbin Ye ,&nbsp;Gao Lin","doi":"10.1016/j.compgeo.2025.107228","DOIUrl":"10.1016/j.compgeo.2025.107228","url":null,"abstract":"<div><div>Seepage problems in half-space domains are crucial in hydrology, environmental, and civil engineering, involving groundwater flow, pollutant transport, and structural stability. Typical examples include seepage through dam foundations, coastal aquifers, and levees under seepage forces, requiring accurate numerical modeling. However, existing methods face challenges in handling complex geometries, heterogeneous media, and anisotropic properties, particularly in multi-domain half-spaces. This study addresses these challenges by extending the modified scaled boundary finite element method (SBFEM) and using this method to explore steady seepage problems in complex half-space domain. In the modified SBFEM framework, segmented straight lines or curves, parallel to the far-field infinite boundary, are introduced as scaling lines, with a one-dimensional discretization applied to them, thereby reducing computational costs.Then the weighted residual method is applied to obtain the modified SBFEM governing equations and boundary conditions of steady-state seepage problem according to the Laplace diffusion equation and Darcy’s law. Furthermore, the steady seepage matrix at infinity is obtained by solving the eigenvalue problem of Schur decomposition and then the 4th-order Runge-Kutta algorithm is used to iteratively solve until the seepage matrix at the boundary lines is reached. Comparisons between the present numerical results and solutions available in the published work have been conducted to demonstrate the efficiency and accuracy of this method. At the same time, the influences of the geometric parameters and complex half-space domain on the seepage flow characteristics in complex half-space domain are investigated in detail.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107228"},"PeriodicalIF":5.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714894","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}

{"title":"Interpretative framework for CPT p-y module tests in drained sands: a practical model for end effect elimination considering sand relative density and surcharge pressure","authors":"Kai Wen ,&nbsp;David J. White ,&nbsp;Benjamin Cerfontaine ,&nbsp;Susan Gourvenec ,&nbsp;Andrea Diambra","doi":"10.1016/j.compgeo.2025.107205","DOIUrl":"10.1016/j.compgeo.2025.107205","url":null,"abstract":"<div><div>Accelerating the current timeline of offshore wind projects is imperative to achieve global decarbonisation plans. In response, a novel in-situ site characterisation tool ROBOCONE is being developed to make the geotechnical design of offshore pile foundations more efficient by directly providing lateral <em>p</em>-<em>y</em> response data, reducing the need for offshore sampling and onshore laboratory testing. This device expands the kinematic range of standard cone penetrometer testing by integrating a robotic cylindrical section capable of horizontal translation, referred to as a p-y module. However, due to the finite length of p-y module, it is necessary to quantify ‘end effects’ to accurately derive <em>p</em>-<em>y</em> curves from the direct measurements of the p-y module. This paper presents detailed three-dimensional finite element analyses of the p-y module in sands, utilizing a bounding surface elastoplastic model that accounts for variations in stress–strain behaviour due to relative density and stress level. The resulting end effect model is underpinned by a two-stage optimisation process that considers key factors such as overburden pressure and relative density. The model’s predictive accuracy is proven through additional finite element analyses different to the calibration cases. The research outcomes offer a robust interpretative framework to accurately determine <em>p</em>-<em>y</em> curves for the design of laterally loaded offshore piles, using the ROBOCONE p-y module.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107205"},"PeriodicalIF":5.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Micromechanical and energetic investigation of shear behavior of sand-rubber mixtures: Effect of rubber content and normal pressure","authors":"Zheng Hu ,&nbsp;Qi Liu ,&nbsp;Beibing Dai","doi":"10.1016/j.compgeo.2025.107221","DOIUrl":"10.1016/j.compgeo.2025.107221","url":null,"abstract":"<div><div>This paper presents a numerical investigation into the effect of rubber content and stress level on the mechanical behavior and energy transformation of sand-rubber mixtures (SRMs) under simple shear condition using a multibody meshfree method. The results reveal that the presence of rubber particles reduces interparticle contact forces, inhibits the formation of strong force chains, and promotes a more uniform force network. The input work is predominantly transformed into strain energy, damping energy, and slipping energy, with the transformation mode heavily dependent on the rubber content and normal stress, which govern the compressibility of SRMs in relation to rubber particles' deformability and the frictional dissipation capacity associated with interparticle friction conditions. The incorporation of rubber particles also enhances the strain energy storage capacity, which is attributed to the restricted particle slipping and rolling behaviors, as well as the diminished particle surface asperity due to rubber particle deformations. These findings provide insights into the macro- and micro-mechanical behavior of SRMs, bridging the gap between the energy transformation and the mechanical response of SRMs, and contributing to the development of more efficient and sustainable geomaterials.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"183 ","pages":"Article 107221"},"PeriodicalIF":5.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714896","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}