Transportation Geotechnics最新文献

{"title":"Performance assessment of 3D-printed scaled geocell-reinforced sandy soils under varying footing sizes","authors":"Ayhan Gurbuz ,&nbsp;Kaan Yunkul ,&nbsp;Sarper Demirdogen ,&nbsp;Huseyin Kalkan","doi":"10.1016/j.trgeo.2025.101751","DOIUrl":"10.1016/j.trgeo.2025.101751","url":null,"abstract":"<div><div>The dimensions of footings play a critical role in determining their ultimate bearing capacity. However, no study in the literature has examined the effect of aspect ratio (<em>AR</em>) under geocell-reinforced conditions. Moreover, previous studies have typically employed fabricated geocells designed for field applications or geogrid-based geocells, in which the geometric dimensions and tensile properties were not appropriately scaled for laboratory model testing. To address these gaps, the present study pioneers the use of 3D-printing technology, which enables the precise simulation of both the geometric dimensions and tensile stiffness of geocells in accordance with established scaling principles, thereby advancing the understanding of geocell-reinforced footings with varying aspect ratios. This study comprises laboratory footing model tests that examines the performance of both unreinforced, scaled 3D-printed geocell-reinforced loose and dense sandy soils to assess the impact of varying aspect ratios of 1, 3 and 10 on the ultimate bearing capacity (<em>q_ult</em>) in terms of footing pressure (<em>q</em>)-settlement ratio (<em>s/B</em>) behavior, critical settlement ratio ((<em>s/B</em>)<em>_cr</em>), soil surface displacement (<em>δ</em>), improvement factor (<em>I_f</em>), reduction in settlement (<em>RS</em>) and the shape factor (<em>S_γ</em>) based on unit weight of soil. The results from tests on dense and loose sandy soils revealed that the maximum ultimate bearing capacity (<em>q_ult)</em> occurred at an aspect ratio (<em>AR</em>) of 1 for reinforced cases and <em>AR</em> of 3 for unreinforced cases while the minimum <em>q_ult</em> was consistently observed at <em>AR</em> of 10 across all tests. Similarly, the maximum <em>S_γ</em> was recorded at <em>AR</em> of 1 for reinforced tests and at <em>AR</em> of 3 for unreinforced tests for both loose and dense sandy soil. Moreover, <em>S_γ</em> also increased for both unreinforced and geocell-reinforced conditions as the internal friction angle increased. It was observed that soil surface displacement (<em>δ</em>) profile was found to influence by <em>AR</em>. Although a linear relationship between the <em>If</em> and <em>RS</em> was evident in the reinforced loose sand cases, this correlation was not observed in the dense sand tests.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101751"},"PeriodicalIF":5.5,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223001","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":"Impact of load frequency on the laboratory transfer function for subgrade soil rutting behavior","authors":"Brayan-Gerardo Arévalo-Mendoza ,&nbsp;Jean-Pascal Bilodeau ,&nbsp;Erdrick-Leandro Pérez-González ,&nbsp;Farshad Kamran ,&nbsp;Papa-Masseck Thiam ,&nbsp;Syrine Chabchoub","doi":"10.1016/j.trgeo.2025.101742","DOIUrl":"10.1016/j.trgeo.2025.101742","url":null,"abstract":"<div><div>Subgrade soil performance and flexible pavement system responses are significantly influenced by loading parameters and environmental factors. The structural rutting in subgrades is especially important, as inadequate permanent strain rates may cause drainage issues that require costly rehabilitation. Unpaved roads are generally located in remote areas and characterized by heavy vehicles, exacerbating this problem. This study emphasizes how crucial load parameters—like amplitude and frequency—impact the accumulation of permanent strain under cyclic loading for different pavement subgrade soils. The research offers comprehensive insights into the behavior and interaction of two distinct subgrade materials, clay and silty sand, through cyclic triaxial testing under varying stress and moisture conditions. Analysis of the transfer curve reveals that frequency is critical in altering the function form, regardless of soil type, water content, or imposed load size. The findings underscore that frequency, more than any other factor, significantly impacts the behavior and characteristics of the pavement structure, making it a key parameter in understanding and predicting structure responses. Furthermore, for a maximum allowable resilient strain, the number of cycles may vary up to 70 times for frequencies ranging from 0.1 Hz to 0.3 Hz. This implies that damage can be accelerated by fewer heavy vehicle passes, especially when the road condition forces the speed to moderate speeds (low frequencies). Assessing the soil stability and rutting potential in situations involving large trucks travelling at slow speeds while carrying heavy loads is crucial. Designers should thus modify their damage criteria to account for these circumstances.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101742"},"PeriodicalIF":5.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222919","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":"Effects of non-homogeneity and anisotropy in the bearing capacity of geosynthetics-reinforced soil-strip foundations under unsaturated conditions","authors":"Xudong Kang ,&nbsp;Zilong Zhang ,&nbsp;Daniel Dias","doi":"10.1016/j.trgeo.2025.101748","DOIUrl":"10.1016/j.trgeo.2025.101748","url":null,"abstract":"<div><div>The ultimate bearing capacity of foundations is a key factor in ensuring the safety and reliability of critical transportation infrastructure. Field evidence shows that subgrade soils are often unsaturated, spatially variable, and anisotropic. However, most existing studies on reinforced soil foundations neglect these features, which can lead to notable discrepancies between theoretical predictions and actual performance. To address this gap, the present study develops a comprehensive framework for evaluating the bearing capacity of reinforced soil foundations. The approach incorporates the effects of soil anisotropy and non-homogeneity on effective cohesion, and introduces an anisotropic soil–water characteristic curve model to capture their influence on hydraulic behavior. Analytical expressions are derived for the shear strength at the reinforcement–soil interface, explicitly accounting for heterogeneity and anisotropy, and a depth-dependent failure mechanism is established. The ultimate bearing capacity is then obtained through the framework of the upper bound theorem. Results highlight that both soil non-uniformity and anisotropy strongly affect the bearing capacity and the optimal reinforcement embedment depth. The proposed method provides a practical and reliable reference for designing reinforced foundations in complex geological environments.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101748"},"PeriodicalIF":5.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222999","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 the superimposed effect of cyclic impact load on subgrade settlement by centrifuge modeling","authors":"Xingxu Yao ,&nbsp;Fangyue Luo ,&nbsp;Ga Zhang ,&nbsp;Yangping Yao","doi":"10.1016/j.trgeo.2025.101746","DOIUrl":"10.1016/j.trgeo.2025.101746","url":null,"abstract":"<div><div>Traffic loads frequently apply a multiple wheel superimposed effect to subgrade, leading to complex characteristics of subgrade settlement that differ from those caused by the single impact load. A series of centrifuge model tests is conducted to investigate the superimposed effect of cyclic impact load on subgrade settlement. The subgrade response is analyzed based on a full-field displacement measurement via image correlation analysis. It is found that the subgrade settlement under superimposed loads extends from the center line to the impact line, contrasting with the localized settlement seen under single loads, and the settlement profile shows an increase in the depth of influence with increasing spacing of superimposed loads but requires fewer impact numbers for settlement stabilization. The analysis of the impact loading mechanism reveals that the settlement exhibits periodic changes within each cycle, with the soil initially exhibiting predominantly plastic deformation, transitioning to predominantly elastic deformation in later stages. A loading influential zone is defined to distinguish the scope of area with loading-induced settlement and the effects of the superimposed load and its spacing are clarified subsequently. Stress propagation from impact loads is observed to be conical, with vertical strain diminishing linearly with depth, indicating basically the same diffusion characteristics across various conditions. The study categorizes loading influential zones into three subzones and further illustrates the superimposed effect.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101746"},"PeriodicalIF":5.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223003","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 study on monitoring model of bearing capacity characteristics of uplift piles based on flexible piezoelectric sensing","authors":"Jun Wang ,&nbsp;Xinzhe Tang ,&nbsp;Zhiming Liu ,&nbsp;Cheng Zhang ,&nbsp;Junfeng Ni ,&nbsp;Ziyang Gao ,&nbsp;Hongtao Fu ,&nbsp;Xueyu Geng ,&nbsp;Chaoyue Wu","doi":"10.1016/j.trgeo.2025.101743","DOIUrl":"10.1016/j.trgeo.2025.101743","url":null,"abstract":"<div><div>As an underground concealed project, pile foundations are often unable to effectively resist groundwater buoyancy, necessitating consideration of anti-floating measures. Given the limitations of current monitoring technologies in achieving real-time, full life-cycle monitoring of uplift piles, the development of distributed, high-precision, and cost-effective monitoring methods remains a key focus in the field. In this study, a sensor-enabled piezoelectric geocable (SPGC) based on flexible piezoelectric sensing is used to monitor the bearing capacity characteristics of uplift piles in a distributed manner. Strain gauges are installed for comparative analysis, and the influences of pile diameter in equal diameter uplift piles and the diameter of the enlarged bottom in enlarged-base uplift piles on their ultimate bearing capacity are investigated. The test results indicate that the variation trend of pile strain obtained from SPGC normalized impedance is generally consistent with that measured by strain gauges, and a linear calculation formula for impedance–strain correlation is established. Significant differences are observed in the axial force and side friction resistance between equal diameter uplift piles and enlarged-base uplift piles. Additionally, the ultimate bearing capacity of uplift piles increases markedly with larger pile diameters and diameter of enlarged bottom. Under the same pile diameter, the ultimate bearing capacity of equal diameter uplift piles is substantially lower than that of enlarged-base uplift piles, with the latter exhibiting a 16.7%-66.7% increase. These findings demonstrate that flexible piezoelectric sensing technology holds promise as a novel solution for the long-term operation and maintenance monitoring of pile foundation anti-floating systems.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101743"},"PeriodicalIF":5.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223006","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 DEM investigation of thermal effects on mechanical properties of biopolymer treated soil","authors":"Jiayu Gu ,&nbsp;Junjun Ni ,&nbsp;Guizhong Xu ,&nbsp;Yanhui Zhou ,&nbsp;Haoyu Zhang","doi":"10.1016/j.trgeo.2025.101744","DOIUrl":"10.1016/j.trgeo.2025.101744","url":null,"abstract":"<div><div>To address the adverse impact of high-temperature climates on soil subgrade and other earthen infrastructures, this study investigates the thermal effects on the mechanical properties of biopolymer treated soils. By conducting temperature-controlled direct shear tests and discrete element method (DEM) simulations, the study examines the influence of temperature on shear strength, deformation characteristics, and microstructural behavior of biopolymer treated soils. Two widely used biopolymers: xanthan gum (XG) and gellan gum (GG) are employed in this study. As the temperature rises from 5 °C to 65 °C, the shear strength of GG treated soil decreases by 50.1 %, whereas XG treated soil experiences a smaller reduction of 21.2 %. DEM simulations reveal that elevated temperatures result in broader shear bands and reduced inter-particle contact forces. Specifically, for untreated soil and XG treated soil, the shear band width increases by 25.9 % and 25.4 %, respectively, as the temperature increases from 5 °C to 65 °C. In contrast, for GG treated soil, the shear band width initially expands by 104.2 %, followed by a reduction of 66.8 %. Furthermore, as the temperature increases from 5 °C to 65 °C, the average contact force of untreated soil, XG and GG treated soil decreases by 15.0 kPa, 24.7 kPa, and 49.4 kPa, respectively. The GG treated soil shows a more significant loss in shear strength and more pronounced microscopic changes. These results suggest that both biopolymers effectively improve soil mechanical properties, while XG demonstrates superior thermal stability, making it more suitable for reinforcing subgrades and embankments in regions with substantial temperature fluctuations.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101744"},"PeriodicalIF":5.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223000","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 study on the failure of a dike foundation caused by backward erosion piping under gradual and sudden hydraulic loads","authors":"Jie Kang ,&nbsp;Jie Ren ,&nbsp;Lei Gan ,&nbsp;Jun Liu ,&nbsp;Zhi Liu ,&nbsp;Lei Xiong ,&nbsp;Cheng Liao","doi":"10.1016/j.trgeo.2025.101738","DOIUrl":"10.1016/j.trgeo.2025.101738","url":null,"abstract":"<div><div>Backward erosion piping (BEP) is a common type of internal erosion that is an important cause of dike failure. To date, research on BEP has been mainly carried out under the action of a gradually increasing hydraulic load, which does not fully represent the actual engineering situation. In this work, the effects of gradually increasing and suddenly applied hydraulic loads on the BEP of double-layer dike foundation are comprehensively studied through laboratory tests. The influences of the exit hole diameter and different types of hydraulic loads on BEP were quantitatively analyzed in terms of the morphological characteristics of the erosion channel, particle loss amount, flow rate of the exit hole and average development speed of the erosion channel. The results show that the occurrence and development process of BEP can be divided into four phases: stabilization, soil expansion, particle erosion and reverse erosion. With the increase of the diameter <em>D</em> of the exit hole, the critical hydraulic gradient <em>i</em>_cr increases, but the local critical hydraulic gradient <em>i</em>_5cm-cr near the exit hole decreases. Compared with that under gradual hydraulic loading, the degree of erosion of a sample under sudden hydraulic loading is higher. The erosion channel depth and width, particle loss rate and exit hole flow rate increase with increasing exit hole diameter <em>D</em>, subcritical coefficient <em>λ</em> and sudden load coefficient <em>µ</em>. The average development rate of the erosion channel increases with larger values of the subcritical coefficient <em>λ</em> and the sudden load coefficient <em>µ</em>, and with smaller values of the exit hole diameter <em>D</em>.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101738"},"PeriodicalIF":5.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159684","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":"Mechanism of the inclined and advanced rockbolt support system and dynamic evaluation of its reinforcement range in mechanized tunneling for high-speed railways","authors":"Jiamin Du,&nbsp;Chuan He,&nbsp;Guowen Xu,&nbsp;Bo Wang,&nbsp;Xu Chen,&nbsp;Gaoyu Ma","doi":"10.1016/j.trgeo.2025.101739","DOIUrl":"10.1016/j.trgeo.2025.101739","url":null,"abstract":"<div><div>To tackle the challenges of tunnel over-excavation, the Chongqing-Kunming High-speed Railway has optimized rockbolt arrangements by replacing traditional radial rockbolts near the tunnel face with pre-stressed inclined rockbolts that are positioned more forward and set at angles of 45° to 60°. This adjustment thereby aims to enhance the stability of the tunnel face, delay steel arch installation, and expand operational space for drilling equipment. Focusing on the case of the Jinyunshan Tunnel, this study employs finite difference modeling (FDM) to analyze the distribution of support stress fields under varying conditions, thereby enabling a quantitative assessment of the rockbolt-reinforced zones. This quantitative evaluation allows for an effective assessment of the feasibility and safety of implementing delayed support sections. Furthermore, triaxial compression simulations that incorporate prestressed rockbolts reveal the impact of confining pressures on the properties of anchored rock masses. Additionally, field and laboratory tests were conducted to further evaluate the effectiveness of tunnel deformation control, the enhancement of surrounding rock stress, and the practical support capabilities of inclined rockbolts. The research results indicate that: (1) The support system establishes an elevated minimum principal stress zone near the tunnel face, enhancing physico-mechanical parameters of the anchored rock as the minimum principal stress increases. (2) With diminishing tunnel face spatial effects, prestress diffusion extends from the vault to the surrounding rock. (3) In the early stages of excavation (0 ∼ 4 m from the tunnel face), inclined rockbolts outperform radial rockbolts by providing more timely support to improve the stress state of the delayed support zone. (4) Critical factors such as burial depth, lateral pressure coefficients, prestress, and rockbolt angle significantly influence the stress field. When the stress in the rockbolts does not exceed their yield strength, optimal support efficiency and cost-effectiveness can be achieved by using 5-meter-long rockbolts installed at a 60° angle.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101739"},"PeriodicalIF":5.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223004","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":"Shakedown limit analysis for heavy-haul railway tracks","authors":"Jinglei Liu ,&nbsp;Shiqi Feng ,&nbsp;Tengfei Wang ,&nbsp;David P. Connolly ,&nbsp;Jing Guo ,&nbsp;Erjun Guo ,&nbsp;Qingzhi Ye","doi":"10.1016/j.trgeo.2025.101741","DOIUrl":"10.1016/j.trgeo.2025.101741","url":null,"abstract":"<div><div>The lower-bound shakedown theorem provides a useful framework for evaluating the long-term stability of structures subjected to cyclic loading by defining both the shakedown limit and critical depth. However, its application in freight railway engineering remains relatively limited. To overcome this gap, shakedown theory has been integrated into the design of heavy-haul railway trackbed systems, enabling assessment of substructure stability under repeated loading. The stress distributions along the longitudinal and transverse axes of the sub-ballast surface, induced by a four-axle loading pattern, were quantified and validated through Gaussian curve fitting. Additionally, a methodology based on the Mohr–Coulomb yield criterion was developed to estimate the shakedown limit of the subgrade, employing the corresponding shakedown axle load as the primary evaluation index. Parametric analyses examined the effects of three key design parameters: the internal friction angle of the sub-ballast, the elastic modulus of the engineered subgrade, and the thickness ratio between the sub-ballast and engineered subgrade. Findings consistently showed that increases in these parameters lead to higher shakedown axle loads. Among them, the internal friction angle of the sub-ballast has the most pronounced influence, whereas the thickness ratio plays a relatively minor role. For example, elevating the internal friction angle from 25° to 40° produces a significant 47.5% rise in the shakedown axle load, highlighting its pivotal contribution to enhancing the substructure’s resilience against cyclic loads.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101741"},"PeriodicalIF":5.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223008","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 characteristics and confinement behavior of geogrid-stabilized railway ballast during tamping operations","authors":"Long Chen ,&nbsp;Juntong Li ,&nbsp;Yujie Feng ,&nbsp;Fengzhuang Tong ,&nbsp;Jie Zhang ,&nbsp;Zixuan Wang ,&nbsp;Yang Yang","doi":"10.1016/j.trgeo.2025.101740","DOIUrl":"10.1016/j.trgeo.2025.101740","url":null,"abstract":"<div><div>Ballasted railway tracks exhibit inherently discrete mechanical behavior, and ballast settlement has become increasingly prominent during long-term railway operations. Geogrid reinforcement has shown significant potential in mitigating ballast settlement; however, the mechanical interaction mechanisms between geogrids and heavy tamping machinery remain insufficiently explored. This study established a coupled model based on the Discrete Element Method (DEM) and Multi-Body Dynamics (MBD) to investigate the micromechanical responses and confinement behavior of geogrid-stabilized ballast during tamping operations. Key findings are as follows: (1) During tamping, the geogrid bears its maximum load in the clamping phase, mainly concentrated beneath the sleeper. This phase is identified as the critical stage for geogrid damage, with a 0.41% higher damage increment than the insertion phase. (2) The contact force distribution of ballast across different horizontal planes demonstrates pronounced anisotropy throughout the tamping process. Among these, the upper sleeper-bottom region and the upper inter-sleeper region are the most sensitive to variations in anisotropy. Ballast in the upper layers beneath and between sleepers exhibits peak contact forces at the beginning of the insertion phase, while the bottom layers are less affected. Middle-layer ballast beneath sleepers shows higher sensitivity during the early clamping phase, whereas middle-layer ballast between sleepers is more sensitive from the end of insertion to the beginning of clamping. (3) Geogrid reinforcement effectively reduces the angular velocity and peak contact force of ballast particles during tamping, thereby lowering the risk of ballast breakage due to high-energy impacts. This enhancement contributes to improved tamping quality, as well as better stability and durability of the trackbed. (4) After twelve tamping operations, the geogrid damage ratio reaches 14.06%, yet its restraining effect remains significant, with an average efficiency of 43.3% (56.5% in the first six cycles and about 30% in the latter six), demonstrating robust stability and long-term durability. This research clarifies the mechanical response and confinement behavior of geogrid-stabilized ballast under tamping operations and provides theoretical guidance for improving the long-term performance of ballasted railway tracks.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"56 ","pages":"Article 101740"},"PeriodicalIF":5.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159685","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}