Transportation Geotechnics最新文献_第4页

Semi-Conv-DETR: A railway ballast bed defect detection model integrating convolutional augmentation and semi-supervised DETR Semi-Conv-DETR：集成卷积增强和半监督 DETR 的铁路道碴床缺陷检测模型

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-18 DOI: 10.1016/j.trgeo.2024.101334

{"title":"Semi-Conv-DETR: A railway ballast bed defect detection model integrating convolutional augmentation and semi-supervised DETR","authors":"","doi":"10.1016/j.trgeo.2024.101334","DOIUrl":"10.1016/j.trgeo.2024.101334","url":null,"abstract":"<div><p>Railway ballast bed defects, including subsidence, mud pumping, and abnormal water, pose significant safety risks by destabilizing the railway ballast beds. Timely detection and repair of railway ballast bed defects are vital for safeguarding the security of both the trains and their passengers. Ground-Penetrating Radar (GPR) is widely used for railway ballast beds inspection and evaluation owing to its high speed and non-destructive characteristics. However, GPR image data contain considerable noise, and the distinct shapes and sizes of each ballast bed defect renders it challenging to apply a unified data annotation standard, which hampers the development of railway ballast bed defect detection models. Considering the distinct wave-like characteristics of GPR data and the vaguely contours of the defects to be identified, we propose a convolutional augmentation operation tailored for GPR images. Furthermore, we also investigate Semi-Supervised Learning by employing limited annotated railway ballast bed inspection data along with a vast amount of unlabeled data to joint train the DETR detection model. To sum up, we proposed a semi-supervised DETR model supplemented with convolutional augmentation for railway ballast bed defect detection, termed as Semi-Conv-DETR model. Experimental outcomes indicate that Semi-Conv-DETR shows an improvement of 58.6 % in accuracy when compared to the classical Faster-RCNN model.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142048949","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}

引用次数: 0

Confinement effect of geocell on the mechanical characteristics of reinforced sand subgrade 土工格室对加固砂基层力学特性的约束效应

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-14 DOI: 10.1016/j.trgeo.2024.101336

{"title":"Confinement effect of geocell on the mechanical characteristics of reinforced sand subgrade","authors":"","doi":"10.1016/j.trgeo.2024.101336","DOIUrl":"10.1016/j.trgeo.2024.101336","url":null,"abstract":"<div><p>Geocell has a confinement effect, limiting the deformation of soil and enhancing the strength of reinforced soil, and has a wide range of application prospects in traffic transportation subgrade engineering. To investigate the confinement effect of geocell on the mechanical characteristics of reinforced sand subgrade, this paper analyzes the macro-mechanical properties of reinforced sand subgrade using triaxial tests, investigates the micro-reinforcement mechanism employing discrete element method (DEM)-based simulations. The potential macro–micro linkages are studied. The experimental results revealed that the volumetric strain of the geocell-reinforced samples increased with the material’s elastic modulus, exhibiting a shear shrinkage phenomenon. The deformation pattern of the reinforced samples presented “segmental deformation,” which differed from that of the unreinforced sand samples. The geocell enhanced the cohesion intercept of the sand samples while having a minimal impact on friction angle. Through the analysis of numerical simulation results, it was found that the geocell constrained the displacement of the soil particles, altering the shear band development trend of the sample and resulting in “segmental deformation”. The geocell facilitated the concentration of force chains, enhancing their stability and resulting in improving the strength in the macro. Additionally, it was observed that the confinement effect of the geocell significantly reduced the fabric and force anisotropy of the granular soil, promoting consistent vertical alignment of force chains. This, in turn, enhanced the vertical force transmission capacity of the sample, explaining the micro-mechanism by which the confinement effect of the geocell increases the peak shear strength of the samples.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141985180","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}

引用次数: 0

Prediction of thermal regime and frost heave deformations of subgrade soils during non-stationary heat and moisture transfer 非稳态热量和湿度传递过程中路基土的热制度和冻胀变形预测

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-14 DOI: 10.1016/j.trgeo.2024.101338

{"title":"Prediction of thermal regime and frost heave deformations of subgrade soils during non-stationary heat and moisture transfer","authors":"","doi":"10.1016/j.trgeo.2024.101338","DOIUrl":"10.1016/j.trgeo.2024.101338","url":null,"abstract":"<div><p>In order to ensure the safe operation of high-speed trains in cold regions, frost heave is one of the basic problems in the research for prediction and control roadbed deformation in such regions. In this paper, based on the classical hydrodynamic model we developed a method of studying thermal regime of soils and predicting frost heave deformations of subgrade soils. Our coupling model takes into account the mutual influence of temperature and soil moisture during non-stationary processes of heat and moisture transfer, calculation of frost heave deformation based on calculated result of the temperature and moisture fields of the roadbed. We have also observed the change of the soil temperatures and frost heave deformation in a freezing-thawing cycle at the geodesic center of PGUPS. The field observation results show that the soil temperature variations amplitude decreases with depth. The simulation verification results and the field observation data show good reproducibility, thus the reliability of the model is confirmed. At last, the paper presents the application of the method in improving high speed railway lines (HSRL) subgrade design in order to reduce frost heave deformations. Based on the results of calculations, it is recommended to lay a thermal insulation layer at the depth of 0.2 m below the subgrade and on the slopes to reduce frost depth and frost heave deformations of subgrade soils.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141997249","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}

引用次数: 0

Enhancing sand liquefaction resistance through microbial-induced partial saturation: An experimental study 通过微生物诱导部分饱和来增强砂土的抗液化能力：实验研究

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-13 DOI: 10.1016/j.trgeo.2024.101337

{"title":"Enhancing sand liquefaction resistance through microbial-induced partial saturation: An experimental study","authors":"","doi":"10.1016/j.trgeo.2024.101337","DOIUrl":"10.1016/j.trgeo.2024.101337","url":null,"abstract":"<div><p>The liquefaction potential of saturated sand can be significantly reduced by inducing partial saturation in the soil. Conventional soil liquefaction mitigation methods, namely soil densification, drainage, cementing, and groundwater lowering, pose environmental concerns and are challenging to apply to pre-existing structures. However, the microbially induced partial saturation (MIPS) method is emerging as a novel and eco-friendly approach to mitigate liquefaction. The MIPS method involves microbial denitrification, which produces nitrogen gas and results in a desaturating effect in the saturated soil. The current study conducted a series of stress-controlled undrained cyclic triaxial tests on saturated sandy soil and microbially-desaturated sandy soil under different relative densities and loading conditions. In addition, the study systematically analyzed the effects of temperature and pH on bacterial activity and the denitrification process. Batch experiments were conducted to establish a relationship between the initial nitrate concentration in the bacterial media and the resulting desaturation.Comprehensive analyses of cyclic resistance curves were performed to gain a thorough understanding. Additionally, the study conducts detailed analyses of the accumulation of excess pore pressure and the resulting axial strains and deformation patterns in both treated and untreated sand. This study demonstrates that the MIPS treatment considerably enhances the liquefaction resistance of treated sand.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142012245","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}

引用次数: 0

Hydraulic influences on the long-term performance of tunnels: A review 水力对隧道长期性能的影响：综述

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-07 DOI: 10.1016/j.trgeo.2024.101329

{"title":"Hydraulic influences on the long-term performance of tunnels: A review","authors":"","doi":"10.1016/j.trgeo.2024.101329","DOIUrl":"10.1016/j.trgeo.2024.101329","url":null,"abstract":"<div><p>Long-term performance of tunnels usually depends on their interaction with surrounding environment induced by various internal and external, natural and anthropogenic factors. Understanding these long-lasting impacts is paramount and crucial for the sustainable lifelong management of tunnel infrastructures. Considering prolonged rainfall, sea level rise and other extreme geohazards partly due to climate change, this paper specifically reviews previous studies examining the hydraulic influences on the long-term performance of tunnels. The variation in groundwater levels, changes in the hydraulic permeability of the surrounding ground and tunnel linings, water leakage, and tunnel deterioration are key hydraulic factors that critically affect the long-term performance of tunnels. The primary objective is to identify research gaps and limitations and provide insights for future research directions to improve our understanding of the long-term performance of tunnels under hydraulic influences. It is found that previous studies often fail to quantify these effects, exemplified by subjectively varying groundwater levels, ground and tunnel permeability and assuming random distribution of tunnel deteriorations. Therefore, future research should focus on adopting laboratory/field data-based, realistic assumptions, aiming to advance the understanding of the performance of tunnels across their lifespan and eventually enhance the principles of tunnel design, construction, and maintenance.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2214391224001508/pdfft?md5=4a6058743867ee2bca921976d13c55f1&pid=1-s2.0-S2214391224001508-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930754","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}

引用次数: 0

Experimental and numerical based model formulation for estimation of subgrade resilient modulus using the repeated load CBR test considering in situ state of stress 利用考虑原位应力状态的重复加载 CBR 试验估算路基弹性模量的实验和数值模型表述

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-05 DOI: 10.1016/j.trgeo.2024.101331

{"title":"Experimental and numerical based model formulation for estimation of subgrade resilient modulus using the repeated load CBR test considering in situ state of stress","authors":"","doi":"10.1016/j.trgeo.2024.101331","DOIUrl":"10.1016/j.trgeo.2024.101331","url":null,"abstract":"<div><p>Characterizing subgrade in terms of resilient modulus is a crucial aspect of flexible pavement design. This paper proposes a methodology and predictive model to estimate the resilient modulus with better consideration of subgrade soils’ in situ stress state using a simple Repeated Load CBR (RLCBR) test. RLCBR tests were conducted on eight subgrade soils at three moisture contents. Numerical studies were conducted by simulating the CBR test in the commercial package LS-DYNA® to understand the stress state under plunger loading concerning field conditions. A new model was proposed for the characterization of subgrade soils based on laboratory RLCBR tests and the FEM, considering the stress state experienced by subgrade soils in the field. The proposed model was validated using data from four other soils and showed good agreement. The study model showed a better predictive capacity for the low plastic subgrade soils than previously developed models. Practicing engineers can use the developed model for estimating the subgrade resilient modulus at the recommended stress state for mechanistic pavement design while understanding the soil’s load-deformation behavior.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930757","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}

引用次数: 0

Real-time pavement surface crack detection based on lightweight semantic segmentation model 基于轻量级语义分割模型的路面表面裂缝实时检测

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-05 DOI: 10.1016/j.trgeo.2024.101335

引用次数: 0

Assessment of the utilization of cement-treated geotextile as a reinforcement element for highway base layer under cyclic loading 评估水泥处理过的土工织物在循环荷载下作为公路基层加固材料的使用情况

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-05 DOI: 10.1016/j.trgeo.2024.101333

{"title":"Assessment of the utilization of cement-treated geotextile as a reinforcement element for highway base layer under cyclic loading","authors":"","doi":"10.1016/j.trgeo.2024.101333","DOIUrl":"10.1016/j.trgeo.2024.101333","url":null,"abstract":"<div><p>This study conducted large-scale cyclic loading experiments on the base layer overlying a weak subgrade soil. Geotextile and cement-treated geotextile were utilized to reinforce the base material and to separate the interface of soils between the base layer and the subgrade. The results obtained from the repeated loading tests using geotextile and cement-treated geotextile were analyzed and evaluated in terms of some benchmark indicators such as total deformation, permanent deformation, elastic deformation, percentage of elastic deformation, traffic benefit ratio (TBR), elastic modulus (M<sub>R</sub>), improvement factor (I<sub>f</sub>), and rut depth reduction ratio (RDR). Based on the experimental results, the use of cement-treated geotextile as a base layer reinforcement element or as an interfacial separation element demonstrated better performance compared to the use of geotextile. Utilization of a cement-treated geotextile as both reinforcement and separation element resulted in an RDR value of 49.26 % after 5000 cycles. Additionally, using a cement-treated geotextile for both reinforcement and separation increased the TBR value to 14.62 at 27 mm deformation, decreased the permanent deformation value from 53.67 mm to 27.23 mm, and approached approximately 2 improvement factor values, compared to using the geotextile solely for separation.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930756","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}

引用次数: 0

Real-time detection of the lateral resistance of ballast bed during track realigning in tamping: A novel test method based on track shifting operation 在捣固过程中实时检测轨道调整时无砟道床的横向阻力：基于轨道移动操作的新型测试方法

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-04 DOI: 10.1016/j.trgeo.2024.101332

{"title":"Real-time detection of the lateral resistance of ballast bed during track realigning in tamping: A novel test method based on track shifting operation","authors":"","doi":"10.1016/j.trgeo.2024.101332","DOIUrl":"10.1016/j.trgeo.2024.101332","url":null,"abstract":"<div><p>Real-time detection of the mechanical state of ballast bed during the tamping operation in railway maintenance is of great significance for improving the effectiveness of operations. In this study, a novel test method named the track shifting test was proposed based on the track realigning operation of the tamping vehicle. The track panel was pushed by the shifting device. Moreover, the lateral resistance of ballast bed was reflected through easily measured indexes. An accurate coupling model of the shifting device and the ballasted track was constructed. Based on the model, the mechanical response of ballast and the track panel induced by the shifting load was analyzed. Results indicated that at an effective loading displacement of <span><math><mrow><mn>2</mn><mrow><mspace></mspace><mtext>mm</mtext></mrow></mrow></math></span>, the lateral resistance of ballast bed within a detectable range of up to five sleepers can be inverted by the shifting force and the displacement of sleepers. A machine learning model was established to obtain the mapping relationship between the shifting force, the displacement of sleepers, and the lateral resistance of ballast bed. Therefore, real-time detection of the lateral resistance was achieved by combining the proposed test method and the machine learning algorithm. This study can contribute to the synchronous detection of the mechanical state of ballast bed during tamping operation.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953548","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}

引用次数: 0

A hybrid methodology for the prediction of subway train-induced building vibrations based on the ground surface response 基于地表响应的地铁列车诱发建筑物振动混合预测方法

IF 4.9 2区工程技术

Transportation Geotechnics Pub Date : 2024-08-02 DOI: 10.1016/j.trgeo.2024.101330

{"title":"A hybrid methodology for the prediction of subway train-induced building vibrations based on the ground surface response","authors":"","doi":"10.1016/j.trgeo.2024.101330","DOIUrl":"10.1016/j.trgeo.2024.101330","url":null,"abstract":"<div><p>The numerical simulation and theoretical methods for the subway train-induced vibration of the shallow foundation buildings often suffer from high cost, unstable prediction accuracy, and lack of clarity of important parameters. Therefore, a hybrid prediction method based on the <em>Z</em>-vibration level at the ground surface was proposed to rapidly obtain the vibration characteristics of the shallow foundation building adjacent to the subway. The numerical simulation was first used to obtain the subway train-induced vibration of the shallow foundation building under different working conditions. Then, a hybrid model was established and retrained by combining the field measurement data of the soil and building vibration along the subway line. Finally, the prediction accuracy of the hybrid model with different numbers of measurement points as input layers was explored, and a case study was performed. The results show that the most noticeable effect on subway train-induced building vibration is the length of the building span among the shallow foundation building parameters. Three measurement points of the <em>Z</em>-vibration level at the ground surface are suggested as the training set data for the input layer of the hybrid model in consideration of computational efficiency and accuracy. The prediction accuracy of the hybrid model gradually increases as the number of data sets increases, and the fully trained hybrid model performs more stable across the frequency range compared to the traditional model, with the majority of its predictions in the 90% confidence interval, which provides the possibility of simplifying the analysis and fast prediction of subway train-induced building vibration.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930758","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}

引用次数: 0