Transportation Geotechnics最新文献

{"title":"Multiphysics simulation of frost heave in unsaturated road systems under covering effect","authors":"Lin Li ,&nbsp;Zepeng Zhang ,&nbsp;Weiling Zu ,&nbsp;Panpan Li ,&nbsp;Weibing Gong","doi":"10.1016/j.trgeo.2025.101526","DOIUrl":"10.1016/j.trgeo.2025.101526","url":null,"abstract":"<div><div>The frost heave of road systems under the covering effect involves the coupled transport of water, heat, and gas, along with the dynamic phase transition of water, vapor, and ice, resulting in a complex multi-physical field coupling process. This study presents a multi-physics numerical model to investigate the frost heave process of road systems in cold regions. The model not only considers the pavement covering effect and the multi-layered structure of the road, but also represents the multi-field coupling and multiphase transitions involved in the system. The model validation is conducted by comparing it with experimental results from a well-documented sample experiment, which simplifies the initial and boundary conditions of the road system calculation profile model. Following the multi-field coupling analysis, a parametric analysis is conducted to explore the impact of different roadbed parameters on the covering effect. Special attention is given to the effects of initial moisture content, temperature gradient, cooling rate, and compactness of fillers on the frost heave process. The results show that the migration and phase transition of vapor impact the freezing process of road systems. In the stable phase of the freeze process, the moisture content at the top of the road substantially exceeds the initial level, a phenomenon driven by vapor migration. This multi-physics simulation can potentially serve as a guidance for studying the frost heave mechanism of road systems in cold regions.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101526"},"PeriodicalIF":4.9,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474835","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":"Research on the hydrothermal process and deformation law of the fill-cut transition section subgrade under dynamic load","authors":"Jinbang Zhai ,&nbsp;Ze Zhang ,&nbsp;Delong Zhang ,&nbsp;Kun Zhang ,&nbsp;Qihao Yu ,&nbsp;Yaqi Zhang","doi":"10.1016/j.trgeo.2025.101524","DOIUrl":"10.1016/j.trgeo.2025.101524","url":null,"abstract":"<div><div>The fill-cut transition section subgrade (FCTSS) is a weak point in subgrade damage. Indoor experiments were conducted to clarify the deformation damage mechanism. It was found that repeated dynamic load leads to upward migration of moisture along the fill-tangent interface and the formation of moisture migration channels. The overall moisture of the soil samples increased under the condition of continuous moisture migration and aggregation. The increase in moisture weakened the strength of the soil, resulting in an increase in moisture accumulation in the region corresponding to the location of greater compressive deformation, which is also the location where damage occurred. Therefore, in order to prevent the effect of dynamic load on the deformation damage of the subgrade, the external recharge of FCTSS should be controlled. This study can provide a valuable reference for the construction and protection of subgrade in the fill-cut transition section in loess areas.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101524"},"PeriodicalIF":4.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445237","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":"Frost heave evaluation and prediction of high-speed railway subgrade with coarse filler in high altitude seasonal frozen region, northwest China","authors":"Xuyang Wu ,&nbsp;Zhanju Lin ,&nbsp;Fujun Niu ,&nbsp;Xingwen Fan ,&nbsp;Minghao Liu ,&nbsp;Chunqing Li ,&nbsp;Yunhu Shang","doi":"10.1016/j.trgeo.2025.101520","DOIUrl":"10.1016/j.trgeo.2025.101520","url":null,"abstract":"<div><div>The subgrade frost heave problem in high altitude seasonal frozen regions is influenced by extreme climatic conditions, geological factors, subgrade structure, and other external variables. Consequently, controlling the frost heave issue becomes challenging. Based on 8 years field monitoring of Lanzhou-Xinjiang high-speed railway (LXHR), the engineering effectiveness of current subgrade anti-frost heave measures in seasonal frozen regions is comprehensively evaluated, and long-term frost heave of subgrade is predicted. The results demonstrate that Geological conditions exert a significant influence on both subgrade frost heave and frozen depth, and the specific manifestations of frost heave are as follows: intermountain basin &gt; Gobi desert &gt; diluvial plain, while the frozen depths are follows: diluvial plain &gt; Gobi desert ≈ intermountain basin. The frost heave in the middle and upper layer of the subgrade (above 1.5 m) constitutes approximately 80 %–87.5 % of the total frost heave. Considering the cumulative increase in subgrade frost heave over time, the subgrade with coarse particle material replacement, and the “two cloth and one film” technique may not be conducive to long-term stability. It is predicted that after 30 years of operation, the subgrade antifreeze layer may transition from being non-sensitive of frost heave to becoming sensitive.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101520"},"PeriodicalIF":4.9,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454118","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":"Probabilistic demand models and fragility analysis of railway embankments subjected to multi-pulse ground motions","authors":"Pan SI ,&nbsp;Liang TANG ,&nbsp;Shuang TIAN ,&nbsp;Yanfang LIU ,&nbsp;Xianzhang LING","doi":"10.1016/j.trgeo.2025.101522","DOIUrl":"10.1016/j.trgeo.2025.101522","url":null,"abstract":"<div><div>The pulse-like ground motion has a substantial impact on long-period structures such as railway embankments. However, previous studies have focused more on comparative analyses of ground motions with and without pulses, without distinguishing between multi-pulse and single-pulse ground motions. This study aims to quantitatively assess the differences in seismic damage to railway embankments when subjected to various pulse-like ground motions, utilizing the seismic fragility analysis method. We executed an incremental dynamic analysis of railway embankments to construct a probabilistic seismic demand model. The most effective intensity measures (IMs) were chosen from among 20 IMs using criteria of correlation, practicality, efficiency, and proficiency. The conditional probability function facilitated fragility curves by applying the optimal IMs and the engineering demand parameters, which represented the peak permanent settlement on the surface of the railway embankment. The results demonstrated the superiority of structure-specific IMs (e.g., velocity spectrum intensity and housner intensity) over acceleration-, velocity-, displacement-, and time-related IMs. The findings revealed that multi-pulse ground motions significantly impacted the uncertainty of railway embankment damage more than single-pulse ground motions, and ignoring their effects led to an underestimation of their fragility in all states of damage.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"52 ","pages":"Article 101522"},"PeriodicalIF":4.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628188","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 behaviors of the geocell reinforced graded aggregates under train loading: Based on Indoor tests and DEM","authors":"Rongwei Fan ,&nbsp;Junjie Huang ,&nbsp;Yanfei Pei ,&nbsp;Zhichao Huang ,&nbsp;Haokun Zhang ,&nbsp;Zongyu Zhang ,&nbsp;Aibo Luo ,&nbsp;Qian Su","doi":"10.1016/j.trgeo.2025.101514","DOIUrl":"10.1016/j.trgeo.2025.101514","url":null,"abstract":"<div><div>Usually, a graded-aggregates layer with a given thickness is laid between a rigid subgrade (box subgrade, pile-plank subgrade) and a ballastless track structure. Such a configuration is realized to achieve features such as dynamic buffering, vibration reduction, energy dissipation, and limitation of uneven settlement. Geocells are typically used to reinforce the graded aggregates layer by enhancing its strength and stiffness. A dynamic test device was independently developed to investigate the mechanical behavior of geocell-reinforced graded aggregates under train loading. The test device can simulate the cyclic train loading and lateral confining pressure on graded aggregates. Subsequently, a comparative test of graded aggregates with geocell and without geocell was carried out by using the device. The above said experiments were simulated by a 3D discrete-element approach that considered the actual shape of the graded aggregate particles. The macroscopic mechanical property changes of graded aggregate under train loads were analyzed from microscopic behaviors such as particle contact and particle migration. This study is intended to provide a basis for optimizing and improving the dynamic performance and evaluation of the ballastless track sandwich subgrade with an upper rigid layer, a middle flexible layer, and a lower rigid layer during long-term service.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101514"},"PeriodicalIF":4.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395380","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 sliding mechanism of slopes along railways in loess regions of China under the coupling effect of extreme rainfall and train vibration","authors":"Kai Han ,&nbsp;Jiading Wang ,&nbsp;Peng Xiao ,&nbsp;Dengfei Zhang ,&nbsp;Bo Cui ,&nbsp;Tao Xiao","doi":"10.1016/j.trgeo.2025.101513","DOIUrl":"10.1016/j.trgeo.2025.101513","url":null,"abstract":"<div><div>This study aims to investigate the sliding mechanism of slopes along railways in loess regions under the coupling effect of extreme rainfall and train vibration. Using the Baotou–Xi’an railway as a case study, a physical model of slopes along railways was developed to account for the impacts of dry-wet cycles, extreme rainfall, and train vibration. The experiments revealed that during the dry-wet cycle phase, the pore fractal dimension of the slope soil decreases from 2.95 to 2.81, indicating an increase in macropores, which enhances water transport efficiency in the soil. Following extreme rainfall, the pore water pressure and moisture content data of the soil approach peak levels, suggesting increased soil saturation and weakened stability. Subsequent vibration loading results in highly saturated soil, as evidenced by fluctuations in volumetric moisture content (from 48 % to 50.7 %) and pore water pressure (from 1.6 to 1.8 Kpa). Train vibration contributes to crack formation and expansion, while water infiltration establishes a pore-crack-seepage network. This network, combined with rainfall and train vibrations, destabilizes the soil structure and triggers landslides in loess regions along railways. The continuous application of vibration load further expands the sliding range. Meanwhile, an equation was derived to determine the sliding distance in relation to the number of vibratory loads applied. The sliding mechanism of slopes along railways under the combined influence of rainfall and train vibration has been preliminarily verified through micro, meso, and macroscopic perspectives.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101513"},"PeriodicalIF":4.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402637","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":"Vibration of the track-soil system due to a harmonic moving load on railway tracks resting on layered soils by 2.5D approach","authors":"Y.B. Yang ,&nbsp;L.T. Xie ,&nbsp;D.S. Yang ,&nbsp;J. Li ,&nbsp;Y.Z. Liu ,&nbsp;Z.L. Wang","doi":"10.1016/j.trgeo.2025.101519","DOIUrl":"10.1016/j.trgeo.2025.101519","url":null,"abstract":"<div><div>Research on the vibrations of track-soil coupling system has been enhanced by the rapid construction of high-speed railways worldwide. As part of the effort to address this problem, a dynamic analysis model composed of the track and soil subjected to a harmonic moving load is analyzed by the 2.5D approach. Focus is placed on the response of the track-soil system caused by the harmonic moving load at sub-critical, critical, and super-critical speeds. The track is modeled as a three-layered structure comprising the rails, sleepers and ballast and the underlying soil is simulated by the 2.5D finite and infinite elements. The train load is treated as a single moving load oscillating with self frequency <span><math><msub><mi>f</mi><mn>0</mn></msub></math></span>. A thorough investigation is presented for the effects of the moving load with various self frequency <span><math><msub><mi>f</mi><mn>0</mn></msub></math></span> at the sub-critical, critical, and super-critical speeds on the ground response. In addition, the effects of the rail and soil properties on the rail response were assessed, as well as on the differential responses of the rails and the ground. The findings of the paper include: (1) The critical speed of the soil is deeply affected by the material properties of the soil and the track, as well as the self frequency <span><math><msub><mi>f</mi><mn>0</mn></msub></math></span> of the load. Particularly, using a stiffer soil or a lighter track helps to mitigate the ground response, while increasing the critical speed <span><math><msub><mi>c</mi><mrow><mi>c</mi><mi>r</mi></mrow></msub></math></span>. (2) A decrease in the shear wave speed ratio of the soil tends to enhance the fluctuation of the ground vibration. At zero self-frequency, increasing soil layer depth <em>H</em> may increase the maximum displacement, while decreasing the vibration fluctuation; as the self-frequency <span><math><msub><mi>f</mi><mn>0</mn></msub></math></span> rises, the effect of soil layer depth <em>H</em> on ground response further diminishes. (3) An increase in the self frequency <span><math><msub><mi>f</mi><mn>0</mn></msub></math></span> of the moving load tends to decrease both the ground response and the level of fluctuation. (4) The higher-frequency rail response for a lighter track on stiffer soils is pronounced prior to arrival of the load at <span><math><mi>t</mi><mo>=</mo><mn>0</mn><mspace></mspace><mi>s</mi></math></span>, while the lower-frequency rail response for a heavier track on a softer soil is more significant after <span><math><mi>t</mi><mo>=</mo><mn>0</mn><mspace></mspace><mi>s</mi></math></span>.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101519"},"PeriodicalIF":4.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402638","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":"Strength evolution mechanism of solid-waste binder solidified sludge soil under drying-wetting/freezing-thawing cycles","authors":"Wen-Jing Sun ,&nbsp;Zhuo-Fan Zhang ,&nbsp;Xiang-Wei Kong ,&nbsp;Qian-Tong Tang ,&nbsp;Yu Xiao ,&nbsp;Anthony Kwan Leung ,&nbsp;Chuang Yu","doi":"10.1016/j.trgeo.2025.101518","DOIUrl":"10.1016/j.trgeo.2025.101518","url":null,"abstract":"<div><div>Binders can enhance soil properties and improve their suitability as subgrade fillers; however, the cementing effect and strength properties of solidified soil are highly susceptible to external environmental factors. This study evaluated the strength and durability of solidified sludge soil (PSCS) with varying binder (PSC) contents through unconfined compressive strength (UCS) tests combined with drying-wetting (D-W) and freezing-thawing (F-T) cycles, and identified the optimal binder content for performance enhancement. Additionally, mercury intrusion porosimetry (MIP) tests were conducted to analyze pore structure changes and explore the synergistic effects between hydration reactions and moisture variations induced by D-W/F-T cycles. Results indicate that binder content &gt; 15 % significantly enhances PSCS strength and durability, with 15 % content (PSCS15) demonstrating the best economic advantage. During D-W/F-T cycles, the synergy between hydration reactions and moisture variations affects the pore structure, resulting in strength changes. For example, during D-W cycles, moisture movement causes the collapse of pores &gt; 30 μm, while hydration products fill the pores, decreasing the porosity of 5–30 μm. Subsequently, moisture variations weaken the cementation effect, leading to a increase in the porosity of 5–30 μm. This process causes the strength to fluctuate, showing a first decrease, followed by an increase, and then another decrease, with an overall reduction of 21.6 %. During the drying stage of D-W cycles, moisture evaporation inhibits hydration reactions in soil. In contrast, during F-T cycles, moisture remains in different physical states (e.g., solid ice crystals and liquid water). These moisture variations causing the collapse of pores &gt; 30 μm, while hydration products fill the larger pores, increasing the porosity of 1–10 μm. The strength first decreases and then increases, with an overall increase of 38.7 %. Furthermore, this study demonstrates that until the hydration process is completed, D-W cycles have a more significant negative impact on PSCS compared to F-T cycles.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101518"},"PeriodicalIF":4.9,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421520","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":"Geotechnical characterisation and sustainability assessment of plastic waste inclusions on a cement-treated fine-grained soil for pavement applications","authors":"Charakho N. Chah ,&nbsp;Sreedeep Sekharan ,&nbsp;Vimal Katiyar","doi":"10.1016/j.trgeo.2025.101515","DOIUrl":"10.1016/j.trgeo.2025.101515","url":null,"abstract":"<div><div>Global economic growth leads to massive plastic waste increase, posing severe environmental challenges worldwide. Addressing it demands innovative solutions like repurposing plastics for construction. Extensive engineering and environmental assessments can accelerate their adoption. This study explores the potential incorporation of plastic waste (in flake and pellet forms) into a cement-treated fine-grained soil through a comprehensive geotechnical experimental testing program and Life Cycle Assessment (LCA) study to assess their environmental sustainability. Experimental investigations were conducted on four distinct plastic types, namely polypropylene (PP), high-density polyethylene (HDPE), polylactic acid (PLA), and polyethylene terephthalate (PET), with varying weight percent inclusions of 2 %, 4 %, and 6 %. Results revealed a decreasing trend in maximum dry densities and strength (both unconfined compressive strength (UCS) and split tensile strength (STS)) with increasing plastic content. Sorptivity of soil generally increased with plastic inclusions, yet in the case of PET, for plastic content &gt; 4 %, a notable drop in the rate of increase was observed. California bearing ratio (CBR) test results indicated a reduction in the CBR values by up to 18.33 % for 6 % plastic inclusions. LCA study findings favoured plastic flakes over pellets as a more sustainable material choice, exhibiting a lower environmental impact across all assessed indicators. This research findings offer insights into the potential utilization of plastic waste and promote sustainable geomaterial choices in road pavement construction.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101515"},"PeriodicalIF":4.9,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387716","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":"Assessment on eco-solidified alkali residue reinforced soft soils for intelligent subgrade constructions","authors":"Jianhua Li ,&nbsp;Zicheng Zhang ,&nbsp;Xu Liu ,&nbsp;Xiaolei Jiao ,&nbsp;Jiale Li","doi":"10.1016/j.trgeo.2025.101516","DOIUrl":"10.1016/j.trgeo.2025.101516","url":null,"abstract":"<div><div>The realization of carbon neutrality can be effectively promoted by the utilization of industrial solid waste in road construction. The alkali residue (AR) is used to modify the soft soil to fulfill the requirement of subgrade construction. A series of compaction tests is performed by considering the coarse- and powdered-reinforced AR soils. The unconfined compressive strength (UCS) is tested with various contents of AR and curing ages. A dataset is established by summarizing the data from literature and laboratory tests. An intelligent model is proposed to design the treatment plan of filling soils in terms of UCS. The environmental impact of chloride diffusion is analyzed. Soluble chloride ions are immobilized using ground granulated blast slag (GGBS) and steel slag to achieve eco-friendly reinforcement of soft soil. The results of the study provide guidance for optimizing soft soil reinforcement performance for subgrade construction, improving resource utilization and reducing soil salinity.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"51 ","pages":"Article 101516"},"PeriodicalIF":4.9,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387718","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}