Transportation Geotechnics最新文献

{"title":"Coupled DEM-FDM study on the dynamic performance of ballast-subgrade system under cyclic axle loading","authors":"Ting Li ,&nbsp;Yuqin Gao ,&nbsp;Yi Zhong ,&nbsp;Peng Xu ,&nbsp;Guangqing Yang","doi":"10.1016/j.trgeo.2025.101737","DOIUrl":"10.1016/j.trgeo.2025.101737","url":null,"abstract":"<div><div>The coupled Discrete Element Method − Finite Difference Method (DEM-FDM) offers a useful approach for comprehensively investigating the micro–macro behavior of ballast-subgrade systems. Previous research primarily focused on the mechanical characteristics of ballast particles, with subgrade response seldom reported simultaneously under cyclic axle loading. This study employs the coupled DEM-FDM method to investigate the dynamic response of the ballast-subgrade system under cyclic axle loading. The movement, contact force, and energy dissipation of the ballast, combined with the stress and settlement of the subgrade, were analyzed in detail to comprehensively understand the influence of axle load magnitude on system behavior.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101737"},"PeriodicalIF":5.5,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159686","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":"Discrete element method analysis on mechanical characteristics and response of prefabricated polyurethane solidified ballasted bed","authors":"Wei Chen ,&nbsp;Yushuo Zhang ,&nbsp;Zili Pan ,&nbsp;Shang Luo ,&nbsp;Weidong Wang ,&nbsp;Qiang Yuan","doi":"10.1016/j.trgeo.2025.101736","DOIUrl":"10.1016/j.trgeo.2025.101736","url":null,"abstract":"<div><div>Conventional ballasted beds (CBB) require frequent maintenance, posing significant economic and durability challenges for railway infrastructure. The prefabricated polyurethane solidified ballasted bed (PSBB) has emerged as a promising alternative, offering enhanced stability and reduced unrecoverable deformation. However, the incorporation of polyurethane foaming agents and prefabricated construction methods alters the mechanical properties of the ballasted bed. The influence of polyurethane module size on these properties and the mechanical response of PSBB under train loading remains insufficiently understood. This study develops a discrete element method (DEM)-based numerical model aligned with the PSBB construction process to investigate the effects of polyurethane module size on mechanical performance. Based on support stiffness considerations, an optimal module size is proposed and evaluated under varying train velocities and axle loads. Subsequent to parameter optimization, the model undertakes an evaluation of both macroscopic responses, including accumulated settlement and dynamic stiffness evolution of the track bed, as well as particle-scale behaviour under cyclic train loading. Compared to the CBB, the PSBB demonstrates reduced unrecoverable settlement and slightly lower dynamic stiffness. Increased train velocities and axle weights lead the PSBB to higher accumulated track settlement while insignificant changes in dynamic stiffness. A thorough examination at the particle level has been conducted, yielding noteworthy findings. The analysis has revealed that PSBB exhibits superior load dispersion characteristics in the vicinity of sleeper ends. This property contributes to a reduction in ballast breakage and track settlement. Above insights offer valuable guidance for the design and implementation of the PSBB in railway systems.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101736"},"PeriodicalIF":5.5,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160296","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":"Landslide susceptibility methodology for railway planning: a comparative analysis of statistical and machine learning methods in a case study of Marche region, Italy","authors":"Rodolfo Rani ,&nbsp;Marco Sciarra ,&nbsp;Stefano Rodani ,&nbsp;Gianluca Benedetti ,&nbsp;Matteo Berti","doi":"10.1016/j.trgeo.2025.101731","DOIUrl":"10.1016/j.trgeo.2025.101731","url":null,"abstract":"<div><div>Landslides pose serious risks to infrastructure, particularly railways, due to their rigid construction and essential transport role. Susceptibility mapping is a valuable tool during the feasibility phase of railway projects, helping identify high-risk areas and inform mitigation strategies. However, effective application requires both reliable classification of landslide types and robust reclassification methods for clear communication with stakeholders. This study presents a comprehensive workflow for landslide susceptibility mapping, combining Weight of Evidence (WoE) and a Generalized Additive Model with boosting (GAMB). We generated separate susceptibility maps for five landslide types and evaluated them using AUROC metrics. The maps were merged into an overall susceptibility map using a complementary probability approach, which also allowed assessment of each type’s sensitivity to the overall susceptibility. To improve threshold reliability, we implemented an ensemble reclassification method using six approaches and applied the statistical mode to define more objective class boundaries. Visualizations of susceptibility along the railway route and its adjacent sides were developed for practical application. The methodology was applied to a 22 km planned railway section in the Marche region (Italy). Results revealed high spatial variability: rockfall types showed the highest accuracy (AUC = 0.94 WoE, 0.98 GAMB), while slides performed poorest. GAMB consistently outperformed WoE in reliability and smoothness of results. Finally, a comparison with EGMS ground motion data showed no significant correlation (R2 ≈ 0.1), underscoring the temporal disconnect between long-term susceptibility and short-term ground deformation.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101731"},"PeriodicalIF":5.5,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223005","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":"Experimental and numerical insights into geosynthetic behavior in pile-supported embankments","authors":"Atefeh Tardast ,&nbsp;S. Hamid Lajevardi ,&nbsp;Laurent Briançon ,&nbsp;S. Mohammad Mirhosseini","doi":"10.1016/j.trgeo.2025.101733","DOIUrl":"10.1016/j.trgeo.2025.101733","url":null,"abstract":"<div><div>Pile-supported embankments on soft soil are currently reinforced by geosynthetics. Many analytical methods have been developed to design geosynthetics, but they are simplistic and do not consider all of the complexity of the developed mechanisms. Despite all of the difficulties met when simulating the behavior of pile-supported embankments in a laboratory, it has been shown that 1 g physical modeling tests can help in understanding this behavior. A new small-scale model is developed to reproduce the behavior of a pile-supported embankment at a scale of 1/10. A study is conducted to find and qualify a foam simulating the behavior of soft soil. The first tests validate the ability of the device to simulate the behavior of a pile-supported embankment correctly. The numerical procedure could also be used to define the load distribution mechanism in geosynthetic pile-supported embankment. Accurate reproduction of stress mechanisms in pile-supported systems requires strict experimental control. Laboratory tests revealed edge and toe stress concentrations, while numerical simulations showed an inverse distribution. These results underscore the necessity of isolating the central grid and realistically modeling soft soil behavior.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101733"},"PeriodicalIF":5.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121165","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":"Macro-meso mechanical behavior and degradation mechanisms of silty clay subgrade subjected to coupled traffic loading and dry-wet cycles","authors":"Kangyu Wang ,&nbsp;Ziliang Qiu ,&nbsp;Haibo Hu ,&nbsp;Miaomiao Sun ,&nbsp;Jiangjing Wang","doi":"10.1016/j.trgeo.2025.101725","DOIUrl":"10.1016/j.trgeo.2025.101725","url":null,"abstract":"<div><div>Existing studies on subgrade soil degradation predominantly isolate traffic loading or dry-wet cycles, neglecting their synergistic impacts and leaving microscale mechanisms underlying macroscale weakening poorly quantified. This study addresses these gaps through a multiscale investigation of silty clay subgrades under coupled traffic loading and cyclic hydration-dehydration using direct shear tests, dynamic triaxial tests, and advanced imaging techniques (computed tomography [CT], scanning electron microscopy [SEM], and mercury intrusion porosimetry [MIP]). Key findings reveal biphasic strength degradation: cohesion (<em>c</em>) decreases by 13.02–21.68 % after five cycles, stabilizing after the second cycle, while the internal friction angle (<em>φ</em>) maintains 89.49 % of the initial capacity. Dynamic resilience modulus (<em>M_R</em>) decreases by 33 % during the initial cycles, with cumulative strains reaching 12.16 % under low confinement (20 kPa) and high moisture (22 %). CT quantification identifies macropores (&gt;100 μm) as dominant (99.95 % porosity), driven by micropores coalescence, linearly correlating with axial strain (0.27 % per 1 % porosity increase at 20 kPa. A refined hyperbolic model, distinct from standard formulations by incorporating moisture-dependent decay parameters (<em>a, b</em>) that capture cyclic hydration effects, accurately predicts strain stabilization (<em>R</em>² &gt; 0.96), validated against experimental data. These results establish explicit linkages between pore network dynamics and mechanical degradation, offering a paradigm shift from isolated to coupled conditioning frameworks and providing practical implications for designing climate-resilient subgrades.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"55 ","pages":"Article 101725"},"PeriodicalIF":5.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120942","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":"Stabilising expansive subgrades with agro-industrial waste: An experimental investigation","authors":"Hamed Faizi,&nbsp;David Airey,&nbsp;Abbas El-Zein","doi":"10.1016/j.trgeo.2025.101729","DOIUrl":"10.1016/j.trgeo.2025.101729","url":null,"abstract":"<div><div>Reusing aluminosilicate wastes in subgrade stabilisation offers three benefits: improving subgrade performance, minimising waste, and reducing dependence on carbon-intensive stabilisers. Previous studies have focused on cement or high NaOH concentrations to achieve strength gains, often at environmental and economic costs. This study explores an alternative approach using low activator doses to control swelling and enhance the viability of aluminosilicate wastes for subgrade stabilisation. An extensive program of one-dimensional free-swell tests under monotonic and cyclic wet–dry conditions was conducted to assess the effects of low activator dosages on soil behaviour, underlying mechanisms, performance, and durability. Mercury intrusion porosimetry, scanning electron microscopy, unconfined compressive strength, x-ray fluorescence, x-ray diffraction, and pH tests were performed to provide deeper insight into the stabilisation process. Results show that swelling stabilisation relies on a distinct but complementary mechanism to strength development, requiring much lower activator concentration (1 M NaOH) and shorter curing (1 day). Swelling in five soils, initially ranging from 24 % to 53 %, was consistently reduced to below 3 %. A fourfold increase in 7-day strength was achieved, driven by activator content and initial dry density. Microstructural analyses show that stabilisation produces denser, less porous material. Stable pH and reduced leachability are recorded over 30-day wetting cycles. pH levels in adjacent soils resemble those in concrete, neutralising over time due to carbonation and dilution. The study hence shows that using aluminosilicate waste for stabilising soils is more likely to be environmentally and economically viable if geopolymerisation is used for swelling reduction and mechanical compaction for strength development, to avoid reliance on expensive high-molarity systems.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"55 ","pages":"Article 101729"},"PeriodicalIF":5.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099258","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":"Evolution and mechanism of passive arching in sand: physical and numerical modeling trapdoor problem","authors":"Yu Zhao ,&nbsp;Yao-Jie Wu ,&nbsp;Jun-Chen Zhang ,&nbsp;Zhi-Yao Tian ,&nbsp;Quan-Mei Gong ,&nbsp;Wei-Jian Li","doi":"10.1016/j.trgeo.2025.101718","DOIUrl":"10.1016/j.trgeo.2025.101718","url":null,"abstract":"<div><div>Uplift or pullout problem in geotechnical engineering issues involve passive soil arching effect. This study presents a series of experimental and numerical investigation on passive arching behavior in sand over a trapdoor. A transparent trapdoor test box, particle image velocimetry technique, and a series of sensors were used to capture the soil mass displacement, shear strain, stress, and load displacement curve during passive arching process. The surface upheaval, horizontal displacement, and volumetric change of sand layer as the passive arching process were quantified. Combining with a series of finite element limit analysis and multiplier elastoplastic finite element analysis, the passive arching behavior of load–displacement response, progressive failure, and stress transfer behavior have been comprehensively presented and evaluated. Initially, companied by compression deformation, a linear increase in load has been recorded. A pair of shear bands formed from the edges of the trapdoor, acquiring an approximately rectangular or inverted trapezoidal failure zone with weak intensity of shear strain. Then, pairs of shear bands with larger inclination angle, surrounding a trumpet-shaped influence zone. When the maximum arching is mobilized, the shear bands extended the surface with maximum inclination angle. The study can provide useful visualized data for modelling a displacement dependent uplift resistance and predicting the sand deformation above an uplifting structure.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"55 ","pages":"Article 101718"},"PeriodicalIF":5.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120941","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":"A novel filter cake formation model for slurry shield excavation integrating slurry seepage-particles clogging and deposition-soil skeleton compression","authors":"Yanbo Chen ,&nbsp;Yandong Lv ,&nbsp;Daosheng Ling ,&nbsp;Xiaowei Ye ,&nbsp;Hao Liu","doi":"10.1016/j.trgeo.2025.101732","DOIUrl":"10.1016/j.trgeo.2025.101732","url":null,"abstract":"<div><div>Current filter cake formation models for slurry shield tunneling fail to take into account the bentonite particle grain size distribution and particle clogging mechanisms, and neglect the effects of skeleton compression caused by soil stiffness variations. However, during the filter cake formation, the particles with different diameters can reduce the pore volume through deposition and clogging, thereby increasing the soil stiffness and reducing permeability. This study considered the effects of bentonite grain size distribution and established a novel filter cake formation model including the coupling behavior of slurry seepage, particle deposition and clogging, and soil skeleton compression with stiffness variations. The proposed model was validated through the experimental results in Yin et al. [<span><span>48</span></span>]. The influences of particle deposition and clogging, and soil stiffness variations on filter cake properties were also investigated. The results show that the particle sieving- and bridging-induced pore clogging play the key role in the reduction of soil porosity and permeability at excavation face before filter cake formation. The volumes of sieved and bridged particles are 61.5 % and 33.7 % of the soil porosity loss, respectively. Neglecting the particle clogging and particle size distribution causes an overestimation of filter cake formation time by 89 %, potentially triggering the excavation face instability. After the filter cake formation, the pore volumes reduced by particle sieving (2.1 %), bridging (1.4 %) and deposition (2.9 %) have slight changes, whereas there is a significant increase in pore compression volume (71.4 %). The proposed model offers a possibility for the construction parameters optimization of slurry shield tunneling.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"55 ","pages":"Article 101732"},"PeriodicalIF":5.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099256","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":"Mechanical response and spray technology for corrosion and voids concrete drainage pipes under traffic loads: simulation and full-scale testing","authors":"Xijun Zhang ,&nbsp;Hongyuan Fang ,&nbsp;Mingrui Du ,&nbsp;Kangjian Yang ,&nbsp;Bin Li ,&nbsp;Chaojie Wang ,&nbsp;Huan Yang ,&nbsp;Junfeng Guan","doi":"10.1016/j.trgeo.2025.101724","DOIUrl":"10.1016/j.trgeo.2025.101724","url":null,"abstract":"<div><div>In various drainage pipeline projects, people widely employ the reinforced concrete drainage pipelines with bell and spigot. Deterioration of drainage pipelines made from reinforced concrete, including bell-and-spigot misalignment, inner wall corrosion and wall bending, can lead to structural failure. Traffic loads is one of the main factors causing pipeline failure. As for the reinforced concrete pipeline, understanding its bending moment becomes very important for pipeline safety evaluation under traffic load. An array of the full-scale tests conducted on buried corroded and void concrete pipeline under traffic loads are introduced in this research. One model of full-scale test parameters is established through numerical simulation analysis, which is adopted with the aim of studying the bending moment of the pipeline made from the reinforced concrete, caused by traffic loads. Firstly, a traffic heavy load model of a pipeline with 1000 mm diameter under a maximum of 300kN was established. Additionally, as for the numerical model, its correctness was verified by full-scale tests. Then, these impacts of traffic load flow, soil cover depth, and position on pipeline bending moment is studied. In order to make the corroded pipeline achieve the original structural performance, this study used this newly developed PVA reinforced cement composite material with early strength and good durability to spray repair the pipeline. The results show that the most unfavorable condition is that with the heaviest traffic load, the vehicle rear axle acts directly on bell-and-spigot joints. If the depth of the soil cover is deeper, the initial pipeline stress will be higher, the influence of traffic loads on the pipeline will be lessened. However, even if a 3 m soil cover depth, heavy trucks still cause a large bending moment, and large-diameter rigid pipelines is designed to be shallow in the cover of the soil, the traffic loads will not be conservative enough in the congested. As to the corroded pipeline repaired by spraying, its structural performance is sufficient to fulfill the original pipeline structure property, which verifies feasibility of the material and technology.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"55 ","pages":"Article 101724"},"PeriodicalIF":5.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099254","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":"Shear properties of breakable soil-rock mixture: effects of shearing scheme and particle concavity","authors":"Cangqian Sun ,&nbsp;Fujiang Chen ,&nbsp;Xiangyang He ,&nbsp;Feng Zeng ,&nbsp;Meiben Gao ,&nbsp;Wuyue She","doi":"10.1016/j.trgeo.2025.101726","DOIUrl":"10.1016/j.trgeo.2025.101726","url":null,"abstract":"<div><div>Soil-rock mixtures (SRM) serve as crucial engineering fill materials, with their shear properties being vital to the stability of infrastructure. To further refine the numerical shear testing scheme for SRM, this study proposes a PFC-FLAC coupling method integrated with a stochastic concave polyhedron generation technique. This approach systematically investigates: (1) the effects of different shearing schemes (stacked ring shear tests versus direct shear testing, SRST versus DST); and (2) the role of gravel particle concavity and breakability on the shear behavior of SRM. Results demonstrate that SRST outperforms DST in capturing the formation of a progressive shear zone, exhibiting a thicker shear zone that yields more realistic mechanical responses and shear strength parameters. Particle concavity simultaneously enhances interlocking mechanisms but promotes particle breakage, collectively governing the shear properties of SRM. Moderately concave gravel particles exhibit optimal compaction efficiency and shear strength, making them the preferred choice for transportation infrastructure fill materials. These findings provide critical insights for optimizing embankment designs in SRM-rich geological environments.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"55 ","pages":"Article 101726"},"PeriodicalIF":5.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099261","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}