Transportation Geotechnics最新文献

{"title":"Evaluation of rock cutting performance of conical cutting tool based on commonly measured rock properties","authors":"","doi":"10.1016/j.trgeo.2024.101318","DOIUrl":"10.1016/j.trgeo.2024.101318","url":null,"abstract":"<div><p>Efficiency of rock cutting process plays a critical role in performance of mechanical excavation units. The composition of cutting forces (normal and drag force acting on cutting tools) and the total force (F_T), specific energy (SE), and percent of fine material (FM) produced in cutting process are important indicators of efficient cutting process. The other key factors in assessment of machine performance are tool wear, energy consumption, dust production, and machine maintenance, availability, and utilization. In this study, small scale linear cutting experiments were performed with a conical pick on thirteen sedimentary and metamorphic weak to medium strength rock samples at a range of 0.5 to 6 mm cutting depths in unrelieved cutting mode. F_T was measured by using a 3D dynamometer and recorded by the data acquisition system, and FM was determined by sieve analysis. Finally, SE was calculated using both the cutting force signal and the volume of the cuttings for each test. Subsequently, an analysis of the effective cutting geometry was performed based on cutting depth, using the specific energy as an indicator of cutting efficiency. Statistical and regression analysis was used to correlate F_T, SE, and FM with the rock properties and cutting geometry. The results revealed that the uniaxial compressive strength, Schmidt rebound number, and density are the main parameters that affect F_T and SE, and the brittleness index is the main parameter that affects FM. A nonlinear predictive model is introduced that offers a reasonable estimate of F_T, SE, and FM to assist engineers in determining the effective operational cutting geometry for a given rock type for unrelieved cuts.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845689","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":"System reliability analysis of geogrid reinforced retaining wall using random finite element method","authors":"","doi":"10.1016/j.trgeo.2024.101316","DOIUrl":"10.1016/j.trgeo.2024.101316","url":null,"abstract":"<div><p>Stabilizing earthwalls is extremely important in geotechnical engineering projects and has become an integral part of transportation infrastructures. Meanwhile, geogrid reinforced retaining walls have been the attention of designers due to their advantages. On the other hand, the soil heterogeneity and the requirement of investigating the internal (geogrid rupture and geogrid pullout) and external (global and lateral displacement) stability modes of these structures have necessitated performing system reliability analysis. In this study, finite element in conjunction with random fields is used to evaluate the reliability of these walls. For this purpose, a finite element program is coded in MATLAB to obtain internal and external safety factors considering staged construction. The deterministic program is extended to a stochastic framework to account for spatial variability of soil parameters in retained backfill, foundation soil, and reinforced fill. In the last part of this study, reliability indices of stability modes are calculated to obtain the series system reliability index, utilizing the Sequential Compounding Method (SCM). The results indicated that the effect of soil heterogeneity is more significant on internal stability modes compared to external stability modes especially geogrid pullout. The results of the system reliability analysis demonstrated more critical conditions thus the reliability index of the system was less than the reliability index of individual components.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141638639","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":"An efficient framework of optimized ensemble paradigm for estimating resilient modulus of subgrades","authors":"","doi":"10.1016/j.trgeo.2024.101315","DOIUrl":"10.1016/j.trgeo.2024.101315","url":null,"abstract":"<div><p>This study employs an efficient framework of ensemble and <em>meta</em>-heuristic optimization algorithm for estimating resilient modulus (M_R) of subgrades with and without considering the influences of freeze–thaw cycles. Notably, M_R is one of the most important stiffness characteristics used in pavement design. The proposed framework combines an ensemble paradigm, random forest regression (RFR), and a widely used <em>meta</em>-heuristic optimization algorithm, grey wolf optimizer (GWO). The outcomes of the established RFR-GWO framework were compared with six regression and neural network-based paradigms namely linear regressor, Gaussian process regression, support vector regressor, artificial neural network, emotional neural network, and multilayer perceptron neural network. For model design and validation, two datasets of A-4, A-6, and A-7–6 (as per AASHTO classification) soils were gathered from the literature. As per experimental results, the developed RFR-GWO achieved the highest degree of accuracy against both datasets with the coefficient of correlation ranging between 0.9970 and 0.9880. To demonstrate the robustness of the established RFR-GWO framework, the impact of the influencing parameters was also investigated via parametric analysis. Overall, the developed RFR-GWO has demonstrated its capability to assist engineers in estimating the subgrade M_R during the initial stage of engineering projects.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141714211","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":"Geogrid stabilization in ballasted trackbed for high-speed railways","authors":"","doi":"10.1016/j.trgeo.2024.101314","DOIUrl":"10.1016/j.trgeo.2024.101314","url":null,"abstract":"<div><p>Ballasted tracks are widely constructed worldwide both for normal, high-speed, and heavy haul railways, which consist of large amounts of diverse-sized gravel particles for a ballast layer of approximately 30 cm just below sleepers. With the increase in in-service time, various distresses, such as particle breakage, ballast fouling, hardening ballast bed, and excessive settlement occur. To clarify the occurrence and evolution mechanism behind these distresses and explore relevant countermeasures, element, model, and field tests have been extensively conducted in last decades, as well as numerical approaches. Geogrid that developed in geotechnical engineering region was found effective in constraining ballast movement and reducing particle breakage in railway engineering. The stabilization effect had also been extensively investigated by element tests and Discrete Element Method (DEM). However, the optimal location of paving geogrid in ballast layer remains unclear to date. Inspired by reproducing the service condition of ballast layer and verifying the obtained results from laboratories, several reduced-scale and full-scale model apparatuses were developed worldwide. One typical apparatus of them established in Zhejiang University has the capacity to mimic the actual train load up to the maximum train speed of 360 km/h and axle load of 30 tons, by which the effect of geogrid on ballasted track stabilization was further validated. It was found that the settlement of the ballast layer was reduced by more than 40 % as a triaxial geogrid was installed at the bottom of the ballast layer. Moreover, the vibration of ballast was significantly decreased even 15 cm above the geogrid. Afterward, field tests were conducted with the same triaxial geogrid installed at the bottom of the ballast layer, notable settlement and vibration reductions effectively proved the stabilization effect of the geogrid. In short, through an overall review on the development and application of geogrids for ballasted track stabilization, these discussions would contribute to a more comprehensive understanding of the internal stabilization mechanism and an efficient application in practice in future.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141706774","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":"Thermal imaging analysis of ballast fouling: Investigating the effects of parent rock and fouling materials through IRT passive camera","authors":"Mehdi Koohmishi ,&nbsp;Sakdirat Kaewunruen ,&nbsp;Guoqing Jing ,&nbsp;Yunlong Guo","doi":"10.1016/j.trgeo.2024.101313","DOIUrl":"https://doi.org/10.1016/j.trgeo.2024.101313","url":null,"abstract":"<div><p>This study explores the use of infrared thermography (IRT) technology for the non-destructive evaluation of ballast fouling in railway tracks, focusing on the influence of parent rock types and fouling materials. Utilizing thermal imaging, the research investigates how variations in ballast conditions affect surface temperature, which serves as an indicator of structural integrity and health. The experimental setup involved ballast samples derived from three different rock types—basalt, limestone, and andesite—fouled with commonly encountered materials like sand and clay at varying percentages. Results demonstrate that fouling level and type significantly influence the thermal signatures captured by IRT passive camera. Notably, ballast derived from darker rocks exhibited higher temperatures, indicating greater emissivity, while fouled ballast showed distinct temperature patterns compared to clean samples, emphasizing the potential of thermal imaging in detecting and quantifying fouling in ballast layers. This research underscores the viability of IRT passive camera in the routine maintenance and monitoring of railway infrastructure, providing a foundation for further development of integrated diagnostic tools for railway management systems.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607437","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":"Heavy rainfall and moisture susceptibility of pavement foundation: A case study coupling finite element method and MnROAD moisture monitoring data","authors":"Md Jibon ,&nbsp;Md Abdullah All Sourav ,&nbsp;Masrur Mahedi ,&nbsp;Sunghwan Kim ,&nbsp;Halil Ceylan ,&nbsp;Raul Velasquez","doi":"10.1016/j.trgeo.2024.101312","DOIUrl":"https://doi.org/10.1016/j.trgeo.2024.101312","url":null,"abstract":"<div><p>The Midwest region, including Minnesota, has been experiencing increased heavy precipitation events due to climate change, and the Minnesota Department of Transportation (MnDOT) is currently investigating the effect of climate change on pavement foundation and other transportation assets. As part of this effort, a study was conducted to investigate the impact of heavy rainfall on pavement foundation performance by focusing on moisture dynamics and resilient modulus changes in the pavement base layer. This study is aimed at understanding the adverse effects of heavy rainfall on moisture fluxes within pavement foundation and corresponding stiffness of the base aggregate layer. A two-step approach was adopted for predicting changes in saturation when estimating corresponding resilient modulus values using the resilient modulus prediction equation employed in AASHTOWare Pavement Mechanistic-Empirical (ME) Design. PLAXIS 3D, a finite-element analysis tool, was utilized to simulate the movement of moisture within the pavement layers under varying heavy rainfall scenarios. By incorporating predicted saturation from PLAXIS 3D simulations into the Pavement ME equation, corresponding resilient modulus values were estimated for the base layer. To ensure its accuracy and reliability, the model was validated using field sensor data from the MnROAD facility. Multiple linear regression models were developed to provide a means for estimating resilient modulus changes due to heavy rainfall. This study highlights the importance of considering moisture effects in pavement design and maintenance in regions prone to heavy rainfall events, and findings can be used by transportation agencies as part of their transportation/geotechnical asset management programs.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607436","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":"Towards automated field ballast condition evaluation: Field validation of the ballast scanning vehicle capabilities","authors":"Jiayi Luo ,&nbsp;Kelin Ding ,&nbsp;Haohang Huang ,&nbsp;Issam I.A. Qamhia ,&nbsp;Erol Tutumluer ,&nbsp;John M. Hart ,&nbsp;Hugh Thompson ,&nbsp;Theodore R. Sussmann","doi":"10.1016/j.trgeo.2024.101311","DOIUrl":"https://doi.org/10.1016/j.trgeo.2024.101311","url":null,"abstract":"<div><p>Ballast degradation can lead to adverse effects such as inadequate drainage, track settlement and reduced lateral stability, which could compromise track safety, daily functionality, and long-term maintenance. Field inspection of ballast for monitoring degradation and functional performance is a challenging task. Current state-of-the-practice methods for evaluating ballast primarily depend on subjective visual inspection, labor-intensive sampling, laboratory sieve analyses or Ground Penetrating Radar (GPR) technology. These methods fall short in providing an in-depth assessment of ballast, specifically in determining the degradation level and aggregate size and shape characteristics at various depths. In this regard, this research developed an innovative ballast investigation platform, the Ballast Scanning Vehicle (BSV), to automate the processes of acquiring detailed ballast inspection data. The BSV utilizes a deep learning-based pipeline for image segmentation to evaluate task-specific metrics such as coarse aggregate gradation, Fouling Index (FI), and continuous track FI depth profiles. This paper provides a detailed overview of the BSV’s functions as well as the different modules of the deep learning-based pipeline. Validation of the BSV’s capabilities was conducted at the Transportation Technology Center (TTC) and is discussed in detail. Based on the field results, the BSV is capable of providing accurate and near real-time evaluation of in-service ballast conditions, serves as a robust means for inspecting long sections of track, and can be used to investigate persistent trouble-spots related to track performance.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2214391224001326/pdfft?md5=9c0babc3599313f71c9d0a5fceefac7a&pid=1-s2.0-S2214391224001326-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141594299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geosynthetic stabilization of road pavements, railroads, and airfields","authors":"E. Tutumluer, M. Kang, I. Qamhia","doi":"10.1016/j.trgeo.2024.101321","DOIUrl":"https://doi.org/10.1016/j.trgeo.2024.101321","url":null,"abstract":"","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847207","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":"Stability assessment of jointed rock capturing roughness degradation under cyclic loading with special reference to railway formation","authors":"Majid Jazebi ,&nbsp;Buddhima Indraratna ,&nbsp;Rakesh Sai Malisetty ,&nbsp;Cholachat Rujikiatkamjorn","doi":"10.1016/j.trgeo.2024.101310","DOIUrl":"https://doi.org/10.1016/j.trgeo.2024.101310","url":null,"abstract":"<div><p>Repeated train loading on a jointed rock subgrade can cause excessive displacements of certain discontinuities leading to instability. Repeated shearing of discontinuities leads to a gradual reduction in joint roughness (i.e. wearing of asperities), which is quantified by the change in the joint roughness coefficient (JRC). This process reduces the joint shear strength over time. In this study, the classical shear strength criterion proposed by Barton and Choubey (1977) is extended to capture the influence of cyclic loading on joint degradation and the corresponding shear strength reduction, also considering the scale effect. This modified cyclic shear strength is implemented in FLAC-3D and validated with conventional cyclic triaxial data available from selected past studies. The model is applied to a simulated real-life track operating over a jointed sandstone formation commonly found towards the eastern coast of NSW. A modified limit equilibrium approach based on an Equivalent Factor of Safety (EFOS) is introduced and adopted to quantify the extent of instability, whereby an increase in the number of loading cycles affects a decrease in the EFOS of an unstable block. For a specific joint strike inclined to the track, the potential adversities are exacerbated when the joint dip angle is greater and when the initial JRC is smaller. In this paper, alternative geometrical combinations and different initial joint properties are considered to determine the worst combination of JRC and joint orientation upon cyclic train loading. As most past studies adhere to traditional static load analyses, the extended shear strength criterion described in this study is novel, and it offers significant practical benefit for railways that are subjected to prolonged cyclic loading.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141482469","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":"Enhanced theoretical approach for predicting the tunnel response due to deep excavation above","authors":"Guohui Feng ,&nbsp;Changjie Xu ,&nbsp;Zhi Ding ,&nbsp;Mingwang Tey ,&nbsp;Zhigang Cao ,&nbsp;Luju Liang ,&nbsp;Xiaozhen Fan ,&nbsp;Kaifang Yang","doi":"10.1016/j.trgeo.2024.101309","DOIUrl":"https://doi.org/10.1016/j.trgeo.2024.101309","url":null,"abstract":"<div><p>The deep excavation will inevitably cause the surrounding soil to move freely, which will have a significant impact on the existing tunnel’s response. The majority of theoretical studies focus on the mechanical equilibrium analysis of tunnel units, rather than selecting the energy method to analyse the soil-tunnel interaction. In this paper, the Rayleigh-Ritz method is utilized to replicate the distortion of the existing tunnel by considering the energy relationship. Moreover, the establishment of the potential energy equation for the existing tunnel can be achieved through the utilization of the Kerr foundation. The variational tunnel deformed energy solution is solved by selecting the minimum potential energy principle, and then the analytical resolution of the tunnel response resulting from the excavation above is obtained. The suggested method’s soundness is evaluated by contrasting it with two field case studies taken from prior research. When compared to the Winkler- and Pasternak-foundation model, which deviated from the proposed method, the outcomes obtained through the proposed method exhibit a closer resemblance to the measured data. According to additional parameter studies, the diameter and depth of the existing tunnel, as well as the elastic modulus of the soil, are significant factors that contribute to the tunnel response caused by the excavation above. The suggested theoretical solution can be utilized to anticipate the potential hazard of the existing tunnel caused by the excavation above in a pertinent engineering project.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141595816","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}