Pub Date : 2026-01-23DOI: 10.1016/j.trgeo.2026.101913
Tianzheng Fu, Stuart Kenneth Haigh
Biocementation, owing to its non-intrusive nature, holds great promise as a non-disruptive solution for improving road pavements, particularly for rehabilitating those experiencing deterioration. The present study provides a direct proof of concept for this application. Full-depth physical models of a three-layer pavement structure, uncemented and biocemented, were constructed and subjected to accelerated testing under increasing wheel loads, with laser scanning and particle image velocimetry (PIV) combined to monitor surface and subsurface deformation. The results showed that both models exhibited a depression in the wheel path and an upheave on the side. The enhanced structural integrity of the biocemented model allowed it to experience significantly reduced deformation while sustaining higher loads. PIV analysis of subsurface displacement and strain fields revealed distinct deformation mechanisms. The uncemented model experienced localized failure within the poorly compacted base with a predominantly contractive response, while the biocemented model involved an active, vertically displacing zone beneath the wheel that underwent volumetric dilation, which was laterally confined by a passive zone on the side. These findings clearly demonstrate the effectiveness of biocementation in improving the structural performance of pavements. However, low treatment efficiency under unsaturated conditions presents a critical challenge for field implementation and warrants further investigations.
{"title":"Biocementation of road pavements: An experimental investigation through physical modeling and accelerated testing","authors":"Tianzheng Fu, Stuart Kenneth Haigh","doi":"10.1016/j.trgeo.2026.101913","DOIUrl":"10.1016/j.trgeo.2026.101913","url":null,"abstract":"<div><div>Biocementation, owing to its non-intrusive nature, holds great promise as a non-disruptive solution for improving road pavements, particularly for rehabilitating those experiencing deterioration. The present study provides a direct proof of concept for this application. Full-depth physical models of a three-layer pavement structure, uncemented and biocemented, were constructed and subjected to accelerated testing under increasing wheel loads, with laser scanning and particle image velocimetry (PIV) combined to monitor surface and subsurface deformation. The results showed that both models exhibited a depression in the wheel path and an upheave on the side. The enhanced structural integrity of the biocemented model allowed it to experience significantly reduced deformation while sustaining higher loads. PIV analysis of subsurface displacement and strain fields revealed distinct deformation mechanisms. The uncemented model experienced localized failure within the poorly compacted base with a predominantly contractive response, while the biocemented model involved an active, vertically displacing zone beneath the wheel that underwent volumetric dilation, which was laterally confined by a passive zone on the side. These findings clearly demonstrate the effectiveness of biocementation in improving the structural performance of pavements. However, low treatment efficiency under unsaturated conditions presents a critical challenge for field implementation and warrants further investigations.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101913"},"PeriodicalIF":5.5,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080494","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}
Pub Date : 2026-01-23DOI: 10.1016/j.trgeo.2026.101914
Ke Wang , Tianxiao Tang , Shanzhen Li , Shuang Tian , Lianzhen Zhang , Shuang Liu , Xianzhang Ling
Frost heave and thaw settlement in frozen high-speed railway subgrades are governed by coupled water and heat migration in the soil, and may be further intensified by traffic-induced vibration. However, the underlying hydro-mechanical processes in frozen, partially saturated subgrades remain poorly quantified, especially when dynamic loading acts concurrently with freeze–thaw cycles. In this study, a custom one-dimensional freezing apparatus with superimposed cyclic loading was used to investigate water migration in unsaturated frozen soils representative of high-speed railway subgrades. A test matrix of ten soil samples was designed, varying freezing temperature (−5℃ to −20℃), soil compaction (90% vs 95% relative), initial moisture content (10%, 14%, 18%), and soil type (silty clay versus gravelly fill). Real-time measurements of temperature, unfrozen water content, water replenishment, and pore water pressure were obtained throughout the experiments. Substantial upward water migration into the freezing zone was observed in all tests. Lower freezing temperatures markedly increased both the volume and rate of water replenishment, whereas compaction (within 90–95%) had little influence. Soil type and layering controlled the magnitude and timing of upward flux: silty clay induced greater and faster water uptake than Group B fill, and layered profiles showed distinct stagewise behavior. Notably, a vibration-induced piston suction mechanism was identified: cyclic vehicular loading acting on a frozen, low-permeability upper layer generated excess pore water pressure in the underlying unfrozen zone, establishing a sustained hydraulic gradient that pumped unfrozen water toward the freezing front. This mechanism is different from mud pumping and pot cover effects. A unified conceptual framework is proposed that links matric suction, cryogenic suction, and vibration-induced piston suction, delineates their respective domains of dominance, and provides physically based guidance for modeling water migration in frozen high-speed railway subgrades and related cold region porous media.
冻土高速铁路路基的冻胀和融沉主要受土壤中水热耦合迁移的控制，并可能在交通振动的作用下进一步加剧。然而，在冻结的、部分饱和的路基中，潜在的水力学过程仍然很难量化，特别是当动力加载与冻融循环同时发生时。本文采用自定义的一维叠加循环加载冻结装置，对具有代表性的高速铁路路基非饱和冻土的水分迁移进行了研究。设计了10个土壤样品的测试基质，不同的冻结温度（- 5℃至- 20℃），土壤压实度（90% vs 95%相对），初始含水量（10%,14%,18%）和土壤类型（粉质粘土与砾石填充）。在整个实验过程中，实时测量温度、未冻水含量、补水和孔隙水压力。在所有试验中都观察到大量向上的水向冻结区迁移。较低的冻结温度显著提高了补水量和补水量，而压实（90-95%）对补水量影响不大。土壤类型和分层控制了上升通量的大小和时间：粉质粘土比B组填土吸收水分更多、更快，分层剖面表现出明显的阶段性特征。值得注意的是，研究人员确定了一种振动诱导的活塞吸力机制：循环车辆荷载作用于冻结的低渗透上层，在下层未冻结区产生超额孔隙水压力，建立持续的水力梯度，将未冻结水泵向冻结前沿。这种机理不同于泥浆泵送和罐盖效应。提出了一个统一的概念框架，将基质吸力、低温吸力和振动诱导活塞吸力联系起来，划定了各自的优势领域，为高速铁路冻土路基及相关寒区多孔介质的水迁移建模提供了基于物理的指导。
{"title":"Water migration in frozen high-speed railway subgrades under traffic vibration: Piston suction versus mud pumping and pot cover effect","authors":"Ke Wang , Tianxiao Tang , Shanzhen Li , Shuang Tian , Lianzhen Zhang , Shuang Liu , Xianzhang Ling","doi":"10.1016/j.trgeo.2026.101914","DOIUrl":"10.1016/j.trgeo.2026.101914","url":null,"abstract":"<div><div>Frost heave and thaw settlement in frozen high-speed railway subgrades are governed by coupled water and heat migration in the soil, and may be further intensified by traffic-induced vibration. However, the underlying hydro-mechanical processes in frozen, partially saturated subgrades remain poorly quantified, especially when dynamic loading acts concurrently with freeze–thaw cycles. In this study, a custom one-dimensional freezing apparatus with superimposed cyclic loading was used to investigate water migration in unsaturated frozen soils representative of high-speed railway subgrades. A test matrix of ten soil samples was designed, varying freezing temperature (−5℃ to −20℃), soil compaction (90% vs 95% relative), initial moisture content (10%, 14%, 18%), and soil type (silty clay versus gravelly fill). Real-time measurements of temperature, unfrozen water content, water replenishment, and pore water pressure were obtained throughout the experiments. Substantial upward water migration into the freezing zone was observed in all tests. Lower freezing temperatures markedly increased both the volume and rate of water replenishment, whereas compaction (within 90–95%) had little influence. Soil type and layering controlled the magnitude and timing of upward flux: silty clay induced greater and faster water uptake than Group B fill, and layered profiles showed distinct stagewise behavior. Notably, a vibration-induced piston suction mechanism was identified: cyclic vehicular loading acting on a frozen, low-permeability upper layer generated excess pore water pressure in the underlying unfrozen zone, establishing a sustained hydraulic gradient that pumped unfrozen water toward the freezing front. This mechanism is different from mud pumping and pot cover effects. A unified conceptual framework is proposed that links matric suction, cryogenic suction, and vibration-induced piston suction, delineates their respective domains of dominance, and provides physically based guidance for modeling water migration in frozen high-speed railway subgrades and related cold region porous media.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101914"},"PeriodicalIF":5.5,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189909","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}
Debris flow disasters pose an increasing threat to bridges, but the damage effect of debris flow impact on high-speed railway track-bridge systems is still not fully understood. This study conducted a comprehensive investigation into the dynamic response, damage evolution, and failure sequence of a CRTS II slab track-bridge system with high piers under debris flow impact. The effects of varying debris flow velocities and impact heights on the damage modes of key structural components, including bridge piers, bearings, sliding layers, and rails, were analyzed in detail. Results indicated that the debris flow acted on the bridge system by inducing pier bending and excessive pier-top lateral deformation, which propagated upward to the bridge and track structures. Peak deformation envelopes along the bridge were generally symmetric. However, the system exhibited significant asymmetric damage and residual deformation, which were mainly attributed to the non-uniform constraint effects of shear alveolars. The fixed bearing at the abutment was prone to early failure, thereby leading to lateral movement of the main girder. Sliding layer damage was concentrated in areas near longitudinal sliding bearings without the shear alveolar. The rails showed asymmetric stepped deformation under the debris flow impacts. A moderate modification of shear alveolars can hardly alleviate the impact damage. Increasing the fixed bearing stiffness at the abutment can restrain the lateral movement of the girder and reduce abnormal rail irregularity.
{"title":"Damage mechanism of high-pier high-speed railway track-bridge system under debris flow impact","authors":"Yujie Yu , Zhewei Fang , Yichuan Zhang , Zhipeng Lai , Lizhong Jiang","doi":"10.1016/j.trgeo.2026.101911","DOIUrl":"10.1016/j.trgeo.2026.101911","url":null,"abstract":"<div><div>Debris flow disasters pose an increasing threat to bridges, but the damage effect of debris flow impact on high-speed railway track-bridge systems is still not fully understood. This study conducted a comprehensive investigation into the dynamic response, damage evolution, and failure sequence of a CRTS II slab track-bridge system with high piers under debris flow impact. The effects of varying debris flow velocities and impact heights on the damage modes of key structural components, including bridge piers, bearings, sliding layers, and rails, were analyzed in detail. Results indicated that the debris flow acted on the bridge system by inducing pier bending and excessive pier-top lateral deformation, which propagated upward to the bridge and track structures. Peak deformation envelopes along the bridge were generally symmetric. However, the system exhibited significant asymmetric damage and residual deformation, which were mainly attributed to the non-uniform constraint effects of shear alveolars. The fixed bearing at the abutment was prone to early failure, thereby leading to lateral movement of the main girder. Sliding layer damage was concentrated in areas near longitudinal sliding bearings without the shear alveolar. The rails showed asymmetric stepped deformation under the debris flow impacts. A moderate modification of shear alveolars can hardly alleviate the impact damage. Increasing the fixed bearing stiffness at the abutment can restrain the lateral movement of the girder and reduce abnormal rail irregularity.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101911"},"PeriodicalIF":5.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080421","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}
Pub Date : 2026-01-20DOI: 10.1016/j.trgeo.2026.101908
Bo Liu , Xueqiang Gong , Yonghao Zhou , Xiewen Hu , Kun He , Jian Cui
Debris flow susceptibility assessment is critical for mitigating risks to large-scale infrastructure, yet existing models often lack dynamic capability by relying solely on static environmental factors. This study identified six environmental factors most closely related to debris flows from 20 static factors, establishing a catchment intrinsic indicator (CII) to reflect debris flow propensity. By integrating CII with hourly rainfall intensity (I60min), we developed a dynamic debris flow susceptibility model—the CII-I model. To demonstrate its applicability, the five rainfall scenarios corresponding to different return periods presented serve as applications. Results indicate that the CII-I model achieves an AUC of 0.926, outperforming Random Forest (RF, AUC = 0.861) and Support Vector Machine (SVM, AUC = 0.866). The high-susceptibility catchments are mainly concentrated in the K45–K65 section of the Fengsha railway (FSR), and all catchments are highly susceptible under the 100-year return period rainfall scenario, consistent with post-event field investigations. Overall, the CII-I model provides improved predictive performance and applicability, establishing a dynamic framework for susceptibility zoning under real rainfall events.
泥石流易感性评估对于降低大型基础设施的风险至关重要，但现有模型往往仅依赖静态环境因素，缺乏动态能力。本研究从20个静态因素中识别出与泥石流关系最密切的6个环境因素，建立了反映泥石流倾向性的流域内在指标（CII）。通过将CII与逐时降雨强度（I60min）相结合，建立了动态泥石流易感性模型——CII- i模型。为了证明其适用性，本文给出了对应于不同回归期的五种降雨情景作为应用。结果表明，ci - i - i模型的AUC为0.926，优于随机森林（RF, AUC = 0.861）和支持向量机（SVM, AUC = 0.866）。高易感流域主要集中在丰沙铁路k45 ~ k65段，在100年回归期降雨情景下，所有流域都是高易感流域，与事件发生后的野外调查结果一致。总体而言，ci - i - i模型提供了更好的预测性能和适用性，建立了真实降雨事件下敏感性分区的动态框架。
{"title":"Dynamic approach-based assessment of debris flow susceptibility in the mountainous area of North China","authors":"Bo Liu , Xueqiang Gong , Yonghao Zhou , Xiewen Hu , Kun He , Jian Cui","doi":"10.1016/j.trgeo.2026.101908","DOIUrl":"10.1016/j.trgeo.2026.101908","url":null,"abstract":"<div><div>Debris flow susceptibility assessment is critical for mitigating risks to large-scale infrastructure, yet existing models often lack dynamic capability by relying solely on static environmental factors. This study identified six environmental factors most closely related to debris flows from 20 static factors, establishing a catchment intrinsic indicator (CII) to reflect debris flow propensity. By integrating CII with hourly rainfall intensity (I<sub>60min</sub>), we developed a dynamic debris flow susceptibility model—the CII-I model. To demonstrate its applicability, the five rainfall scenarios corresponding to different return periods presented serve as applications. Results indicate that the CII-I model achieves an AUC of 0.926, outperforming Random Forest (RF, AUC = 0.861) and Support Vector Machine (SVM, AUC = 0.866). The high-susceptibility catchments are mainly concentrated in the K45–K65 section of the Fengsha railway (FSR), and all catchments are highly susceptible under the 100-year return period rainfall scenario, consistent with post-event field investigations. Overall, the CII-I model provides improved predictive performance and applicability, establishing a dynamic framework for susceptibility zoning under real rainfall events.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101908"},"PeriodicalIF":5.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039520","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}
Pub Date : 2026-01-19DOI: 10.1016/j.trgeo.2026.101903
O. Guerrero-Bustamante , A. Guillen , F. Moreno-Navarro , M.C. Rubio-Gámez , M. Sol-Sánchez
This research presents an experimental evaluation of diverse bituminous materials for high-performance sub-ballast in railway tracks, produced through various manufacturing technologies including hot, warm, and cold mix asphalt, focusing on mixtures with 100% reclaimed asphalt pavement (RAP). The research addresses a strategic line toward more sustainable materials for railway tracks, while covering key gaps in understanding the mechanical and vibrational behavior of bituminous sub-ballast specifically used in railway applications. A comprehensive testing program was designed to evaluate crucial characteristics of these materials validating their functionality and suitability, like indirect tensile strength and stiffness, permanent deformation, vibration-damping capacity, permeability, and bearing capacity. Among the findings, RAP-based hot and warm mix asphalt (HMA-R and WMA-R) showed superior mechanical performance, with increases of up to 73% in strength and 84% in stiffness compared to conventional HMA. However, HMA-R exhibited increased brittleness due to excessive stiffening. In contrast, the temperature reduction in WMA-R helped restore mixture ductility and toughness, offering a more balanced behavior despite its high RAP content. In terms of vibration mitigation, WMA-R achieved a 31% reduction in acceleration and maintained a damping performance comparable to conventional granular references. Bituminous RAP mixtures also exhibited appropriate subgrade protection, with up to 70% lower infiltration rates, water sensitivity ratios exceeding 90%, and excellent bearing capacity. To facilitate performance comparison, a multi-criteria framework was developed, integrating weighted improvement indicators across four behavioral categories. WMA-R emerged as the most technically balanced solution, offering a favorable compromise between structural performance and vibration control for modern, sustainable railway infrastructures.
{"title":"Comparative evaluation of high-RAP bituminous and granular sub-ballast mixtures for railway infrastructure","authors":"O. Guerrero-Bustamante , A. Guillen , F. Moreno-Navarro , M.C. Rubio-Gámez , M. Sol-Sánchez","doi":"10.1016/j.trgeo.2026.101903","DOIUrl":"10.1016/j.trgeo.2026.101903","url":null,"abstract":"<div><div>This research presents an experimental evaluation of diverse bituminous materials for high-performance sub-ballast in railway tracks, produced through various manufacturing technologies including hot, warm, and cold mix asphalt, focusing on mixtures with 100% reclaimed asphalt pavement (RAP). The research addresses a strategic line toward more sustainable materials for railway tracks, while covering key gaps in understanding the mechanical and vibrational behavior of bituminous sub-ballast specifically used in railway applications. A comprehensive testing program was designed to evaluate crucial characteristics of these materials validating their functionality and suitability, like indirect tensile strength and stiffness, permanent deformation, vibration-damping capacity, permeability, and bearing capacity. Among the findings, RAP-based hot and warm mix asphalt (HMA-R and WMA-R) showed superior mechanical performance, with increases of up to 73% in strength and 84% in stiffness compared to conventional HMA. However, HMA-R exhibited increased brittleness due to excessive stiffening. In contrast, the temperature reduction in WMA-R helped restore mixture ductility and toughness, offering a more balanced behavior despite its high RAP content. In terms of vibration mitigation, WMA-R achieved a 31% reduction in acceleration and maintained a damping performance comparable to conventional granular references. Bituminous RAP mixtures also exhibited appropriate subgrade protection, with up to 70% lower infiltration rates, water sensitivity ratios exceeding 90%, and excellent bearing capacity. To facilitate performance comparison, a multi-criteria framework was developed, integrating weighted improvement indicators across four behavioral categories. WMA-R emerged as the most technically balanced solution, offering a favorable compromise between structural performance and vibration control for modern, sustainable railway infrastructures.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101903"},"PeriodicalIF":5.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996325","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}
Pub Date : 2026-01-19DOI: 10.1016/j.trgeo.2026.101906
Junchen Zhang , Liufeng Su , Wang Wu , Yanliang Du , Qixiang Yan , Yu Zhao
The performance status of circular Tunnel Boring Machine tunnels predominantly relies on qualitative evaluations using limited indicators, which fail to fully utilize high-volume field data from modern detection technologies, resulting in suboptimal specificity and reliability of the analysis outcomes. This study proposed a new assessment method for safety status of circular tunnels considering the integration of analytical models with displacement data. The assessment method fully considered the multisource data including the geological information, tunnel dimensions, actual lining displacements, lining reinforcement, and nonlinear constitutive relationships of the lining materials. The internal forces and stresses of the circular tunnel were calculated by the analytical models. Numerical modeling validation confirmed the model’s reliability. The applicable scope of the assessment method was clarified through the parameter sensitivity analyses. A safety evaluation index and its classification derived from the assessment method were subsequently established. The research findings reveal that the correlation coefficients (between test values and analytical values) of lining displacement, bending moment and axial force are more than 98 %, 97 % and 86 % respectively under the shallow and deep buried tunnel scenarios, which verified the reliability of the integration between analytical models and displacement data. The mechanical behaviors of a circular tunnel are influenced by factors such as the geological types, tunnel dimensions, lining displacements, lining reinforcement and lining material types. The ratio of lining stress to its yield strength (stress-strength ratio) ultimately determines the safety of the tunnel. It is worth mentioning that the safety state of the lining ring cannot be identified separately by the ovality of displacement, which should be determined jointly by the major and minor axes of the elliptical deformation. According to parameter sensitivity analysis, the order of sensitivity influence on the stress-strength ratio is: structural displacement > lining thickness > tunnel diameter > lining strength > soil lateral pressure coefficients. The assessment method synergizes with detection technology advancements, which provides theoretical foundations for predicting the mechanical performance of service tunnels.
{"title":"A new assessment method for safety status of circular tunnels considering the integration of analytical models with displacement data","authors":"Junchen Zhang , Liufeng Su , Wang Wu , Yanliang Du , Qixiang Yan , Yu Zhao","doi":"10.1016/j.trgeo.2026.101906","DOIUrl":"10.1016/j.trgeo.2026.101906","url":null,"abstract":"<div><div>The performance status of circular Tunnel Boring Machine tunnels predominantly relies on qualitative evaluations using limited indicators, which fail to fully utilize high-volume field data from modern detection technologies, resulting in suboptimal specificity and reliability of the analysis outcomes. This study proposed a new assessment method for safety status of circular tunnels considering the integration of analytical models with displacement data. The assessment method fully considered the multisource data including the geological information, tunnel dimensions, actual lining displacements, lining reinforcement, and nonlinear constitutive relationships of the lining materials. The internal forces and stresses of the circular tunnel were calculated by the analytical models. Numerical modeling validation confirmed the model’s reliability. The applicable scope of the assessment method was clarified through the parameter sensitivity analyses. A safety evaluation index and its classification derived from the assessment method were subsequently established. The research findings reveal that the correlation coefficients (between test values and analytical values) of lining displacement, bending moment and axial force are more than 98 %, 97 % and 86 % respectively under the shallow and deep buried tunnel scenarios, which verified the reliability of the integration between analytical models and displacement data. The mechanical behaviors of a circular tunnel are influenced by factors such as the geological types, tunnel dimensions, lining displacements, lining reinforcement and lining material types. The ratio of lining stress to its yield strength (stress-strength ratio) ultimately determines the safety of the tunnel. It is worth mentioning that the safety state of the lining ring cannot be identified separately by the ovality of displacement, which should be determined jointly by the major and minor axes of the elliptical deformation. According to parameter sensitivity analysis, the order of sensitivity influence on the stress-strength ratio is: structural displacement > lining thickness > tunnel diameter > lining strength > soil lateral pressure coefficients. The assessment method synergizes with detection technology advancements, which provides theoretical foundations for predicting the mechanical performance of service tunnels.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101906"},"PeriodicalIF":5.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039521","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}
Pub Date : 2026-01-11DOI: 10.1016/j.trgeo.2026.101902
Min Wang , Kaiyi Li , Jie Wang , Zhuowei Li , Hui Lv , Lulu Hu
Epoxy chip seal as an effective means to improve the anti-skid performance of concrete pavements is increasingly widely used, its skid resistance is significantly affected by its surface texture, but its skid resistance performance and durability analysis method is single. To address the these issues, a high toughness modified epoxy resin chip seal structure was developed to carry out indoor accelerated abrasion test, selecting the material bearing area curve and three-dimensional power spectrum function to study the surface texture structure and decay law of the epoxy chip seal specimen with different abrasion time, analyze the relationship between the three-dimensional surface roughness power spectrum function and the coefficient of friction, and study the effect of the different contact area ratios and wavelengths on the dynamic friction. The results show that in the abrasion process, the degree of abrasion at the top of the aggregate is larger than that at the bottom, and the influence of the surface micro-texture structure on the coefficient of kinetic friction is larger than that of the macro texture, the effective contact area of epoxy chip seal specimens with two aggregate sizes of 2–3 mm and 3–5 mm are 30∼40 % and 20∼40 % respectively, and the corresponding optimal wavelengths are 0.2 mm–5.04 mm, 0.3 mm–5.04 mm, at the same time, the correlation coefficient of the dynamic friction coefficient model based on the surface roughness power spectrum function and abrasion time under the multi-scale texture structure reaches 0.8, which shows that the use of the surface texture power spectrum density function can effectively evaluate the anti-skidding performance of the pavement.
{"title":"Analysis of skid resistance of epoxy chip seal based on three-dimensional power spectrum","authors":"Min Wang , Kaiyi Li , Jie Wang , Zhuowei Li , Hui Lv , Lulu Hu","doi":"10.1016/j.trgeo.2026.101902","DOIUrl":"10.1016/j.trgeo.2026.101902","url":null,"abstract":"<div><div>Epoxy chip seal as an effective means to improve the anti-skid performance of concrete pavements is increasingly widely used, its skid resistance is significantly affected by its surface texture, but its skid resistance performance and durability analysis method is single. To address the these issues, a high toughness modified epoxy resin chip seal structure was developed to carry out indoor accelerated abrasion test, selecting the material bearing area curve and three-dimensional power spectrum function to study the surface texture structure and decay law of the epoxy chip seal specimen with different abrasion time, analyze the relationship between the three-dimensional surface roughness power spectrum function and the coefficient of friction, and study the effect of the different contact area ratios and wavelengths on the dynamic friction. The results show that in the abrasion process, the degree of abrasion at the top of the aggregate is larger than that at the bottom, and the influence of the surface micro-texture structure on the coefficient of kinetic friction is larger than that of the macro texture, the effective contact area of epoxy chip seal specimens with two aggregate sizes of 2–3 mm and 3–5 mm are 30∼40 % and 20∼40 % respectively, and the corresponding optimal wavelengths are 0.2 mm–5.04 mm, 0.3 mm–5.04 mm, at the same time, the correlation coefficient of the dynamic friction coefficient model based on the surface roughness power spectrum function and abrasion time under the multi-scale texture structure reaches 0.8, which shows that the use of the surface texture power spectrum density function can effectively evaluate the anti-skidding performance of the pavement.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101902"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039519","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}
Pub Date : 2026-01-10DOI: 10.1016/j.trgeo.2026.101898
Hao Liu , Yiheng Pan , Xinqiang Gao , Song Hu
Researchers had presumed different failure mechanisms for calculating the load on culverts, but the research on summarizing, comparing, and evaluating these failure mechanisms was limited. This paper estimates the failure surface and shear stress along the failure surface by numerical analysis, following a brief summary of the methods for calculating the load on the culvert. From the simulation, three types of failure surfaces, i.e., internal, vertical, and external failure surfaces, were observed in the fill. Among them, the dominant surface depended on the friction angle and height. In addition, the lateral earth pressure coefficient at the vertical and dominant failure surface decreased with the fill height and friction angle, contrary to the assumption that the lateral earth pressure coefficient was only influenced by the fill friction angle. Furthermore, when the external and dominant failure surface was simplified as the vertical failure surface with an equivalent settlement surface (ESS), the vertical earth pressure in the interior fill could be accurately calculated if an appropriate value for the ESS height was chosen.
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The dynamic interaction between pile and saturated soil governs pile settlement in soft soil foundation, which is strictly controlled in high-speed railways. However, the underlying mechanisms governing the transformation of dynamic load within the pile-soil system and their evolution over time remain inadequately understood. Therefore, conventional design methods that rely solely on static pile capacity and neglect dynamic interaction effects are inapplicable. In this study, a series of centrifuge modelling tests were conducted using a self-developed dynamic loading device and an instrumented model pile. The setup adequately satisfied the similitude requirements for intensified loading frequency and stress wave propagation along pile. Various static and dynamic loads were applied to the pile embedded in saturated silty soil, with frequencies reaching 360 Hz and cycles up to 5 × 105. Complementary numerical analyses were also performed to elucidate the mechanisms of dynamic pile-soil interaction. Experimental and numerical results demonstrate that stress waves propagated from the pile shaft into the surrounding soil in the form of Mach cone, driven by the differences in wave velocities between pile and soil. Moreover, soil vibration attenuated with increasing distance from the pile, a trend predictable using Bornitz’s approach even under loading frequencies as high as 360 Hz. The evolution of pore water pressure and the corresponding redistribution of axial force along the pile reveal distinct pile-soil interaction responses under different loading amplitudes: (1) Under low-amplitude loads (CLR ≤ 0.3), pore water pressure accumulation was negligible, shaft resistance carried most of the pile-head load without significant degradation, and base resistance remained minimal; (2) Under moderate loads (0.4 ≤ CLR ≤ 0.5), pore pressure accumulated noticeably, shaft resistance gradually degraded, axial force was transmitted to deeper pile segments, and base resistance increased but remained below its ultimate threshold; (3) Under high-amplitude loads (CLR ≥ 0.6), buildup of pore water pressure was most pronounced, shaft resistance degradation was substantial, base resistance increased significantly compared with moderate load levels, and deformation of the soil beneath the pile tip accumulated rapidly. Ultimately, these micromechanical processes led to distinct macro-scale settlement behaviours, i.e., stable, metastable, and unstable developments, which can be consistently explained by the evolving dynamic pile-soil interaction.
{"title":"Load transfer mechanism and interaction evolution in pile-soil system to high-frequency axial load: Centrifuge modelling and numerical analysis","authors":"Feng Qin , Xuecheng Bian , Zizhuang Yan , Yu Zhao , Chuang Zhao","doi":"10.1016/j.trgeo.2026.101904","DOIUrl":"10.1016/j.trgeo.2026.101904","url":null,"abstract":"<div><div>The dynamic interaction between pile and saturated soil governs pile settlement in soft soil foundation, which is strictly controlled in high-speed railways. However, the underlying mechanisms governing the transformation of dynamic load within the pile-soil system and their evolution over time remain inadequately understood. Therefore, conventional design methods that rely solely on static pile capacity and neglect dynamic interaction effects are inapplicable. In this study, a series of centrifuge modelling tests were conducted using a self-developed dynamic loading device and an instrumented model pile. The setup adequately satisfied the similitude requirements for intensified loading frequency and stress wave propagation along pile. Various static and dynamic loads were applied to the pile embedded in saturated silty soil, with frequencies reaching 360 Hz and cycles up to 5 × 10<sup>5</sup>. Complementary numerical analyses were also performed to elucidate the mechanisms of dynamic pile-soil interaction. Experimental and numerical results demonstrate that stress waves propagated from the pile shaft into the surrounding soil in the form of Mach cone, driven by the differences in wave velocities between pile and soil. Moreover, soil vibration attenuated with increasing distance from the pile, a trend predictable using Bornitz’s approach even under loading frequencies as high as 360 Hz. The evolution of pore water pressure and the corresponding redistribution of axial force along the pile reveal distinct pile-soil interaction responses under different loading amplitudes: (1) Under low-amplitude loads (CLR ≤ 0.3), pore water pressure accumulation was negligible, shaft resistance carried most of the pile-head load without significant degradation, and base resistance remained minimal; (2) Under moderate loads (0.4 ≤ CLR ≤ 0.5), pore pressure accumulated noticeably, shaft resistance gradually degraded, axial force was transmitted to deeper pile segments, and base resistance increased but remained below its ultimate threshold; (3) Under high-amplitude loads (CLR ≥ 0.6), buildup of pore water pressure was most pronounced, shaft resistance degradation was substantial, base resistance increased significantly compared with moderate load levels, and deformation of the soil beneath the pile tip accumulated rapidly. Ultimately, these micromechanical processes led to distinct macro-scale settlement behaviours, i.e., stable, metastable, and unstable developments, which can be consistently explained by the evolving dynamic pile-soil interaction.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"57 ","pages":"Article 101904"},"PeriodicalIF":5.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978090","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}
Pub Date : 2026-01-08DOI: 10.1016/j.trgeo.2026.101901
Daxiang Liu , Yexiong Zhou , Zhihai Xu , Qiangbing Song , Yuliang Qin , Zuosen Luo , Yao Xiao , Xudong Hu , Dong Xia , Liming Liu , Mingtao Zhou , Huafeng Deng , Wennian Xu , Yueshu Yang
Engineering damaged exposed slopes often experience severe soil degradation, with soils predominantly composed of weathered bedrock. When such soils are used as ecological slope protection substrates, they commonly exhibit inadequate geotechnical strength and low fertility, which severely restrict the effectiveness and long-term durability of ecological slope protection engineering. Addressing this challenge, this study investigates the potential of combining biochar (BC) and microbially induced calcium precipitation (MICP) to enhance the structural and ecological performance of sandy ecological substrates (SSs). A series of pumping-grouting and plant cultivation experiments were conducted to evaluate the individual and synergistic effects of BC and MICP. Results showed that BC improved porosity and plant growth but reduced dry density, shear strength, and disintegration resistance. MICP significantly increased mechanical strength but inhibited plant growth. When combined, BC facilitated microbial adhesion and CaCO3 precipitation, enhancing MICP performance while reducing BC degradation. However, excessive BC content negatively impacted substrate strength and mineralization efficiency. Optimization experiments identified ideal conditions: 1-2% BC by mass, bacterial concentration at OD600 = 1.0, and calcium acetate and urea at 1.0 mol/L. This optimized scheme significantly improves the structural and ecological performance of SSs with minimal adverse effects on vegetation, demonstrating strong potential for practical ecological slope engineering applications.
{"title":"Efficient improvement of physicochemical properties and plant growth in sandy ecological substrates: performance and mechanisms of biochar-based materials","authors":"Daxiang Liu , Yexiong Zhou , Zhihai Xu , Qiangbing Song , Yuliang Qin , Zuosen Luo , Yao Xiao , Xudong Hu , Dong Xia , Liming Liu , Mingtao Zhou , Huafeng Deng , Wennian Xu , Yueshu Yang","doi":"10.1016/j.trgeo.2026.101901","DOIUrl":"10.1016/j.trgeo.2026.101901","url":null,"abstract":"<div><div>Engineering damaged exposed slopes often experience severe soil degradation, with soils predominantly composed of weathered bedrock. When such soils are used as ecological slope protection substrates, they commonly exhibit inadequate geotechnical strength and low fertility, which severely restrict the effectiveness and long-term durability of ecological slope protection engineering. Addressing this challenge, this study investigates the potential of combining biochar (BC) and microbially induced calcium precipitation (MICP) to enhance the structural and ecological performance of sandy ecological substrates (SSs). A series of pumping-grouting and plant cultivation experiments were conducted to evaluate the individual and synergistic effects of BC and MICP. Results showed that BC improved porosity and plant growth but reduced dry density, shear strength, and disintegration resistance. MICP significantly increased mechanical strength but inhibited plant growth. When combined, BC facilitated microbial adhesion and CaCO<sub>3</sub> precipitation, enhancing MICP performance while reducing BC degradation. However, excessive BC content negatively impacted substrate strength and mineralization efficiency. Optimization experiments identified ideal conditions: 1-2% BC by mass, bacterial concentration at OD<sub>600</sub> = 1.0, and calcium acetate and urea at 1.0 mol/L. This optimized scheme significantly improves the structural and ecological performance of SSs with minimal adverse effects on vegetation, demonstrating strong potential for practical ecological slope engineering applications.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"58 ","pages":"Article 101901"},"PeriodicalIF":5.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190112","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}
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