Transportation Geotechnics最新文献

{"title":"DEM Simulations of Seismic Response of the Ballasted Track","authors":"Huan Wang ,&nbsp;Shanshan Ye ,&nbsp;Xiaolin Weng ,&nbsp;Dong Ding ,&nbsp;Siyu Chen","doi":"10.1016/j.trgeo.2024.101472","DOIUrl":"10.1016/j.trgeo.2024.101472","url":null,"abstract":"<div><div>Railway lines often intersect with seismic zones, making them susceptible to earthquake-induced damage. Ballasted tracks, widely used worldwide, have a complex dynamic response under seismic loading. However, the characteristics of these responses and the evolution of lateral ballast resistance (LBR) remain incompletely understood. This study aims to fill this gap by establishing a numerical model using the discrete element method to analyze the dynamic response and seismic-induced degradation of the LBR. The macroscopic and microscopic responses of ballasted track structures under varying peak ground accelerations (PGAs) are both analyzed including the displacement, force chain, particle flow, and LBR degradation under seismic conditions. It is found that the displacement amplitude of the ballast increases with rising PGA and shows a greater increase on the slope surface than at the center of the track bed. The LBR decreases as PGA increases, with reductions of 2.4 %, 7.8 %, and 16.5 % at PGAs of 0.1 g, 0.2 g, and 0.3 g, respectively. The disturbance range expands, and the number of force chains and dispersed ballast particles increases with higher PGA. In regions with varying seismic intensity, shoulder width and height have minor effects on LBR in low-intensity areas but significantly impact LBR in high-intensity areas. These insights provide valuable guidance for seismic prevention strategies and post-earthquake restoration efforts for ballasted tracks.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101472"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102347","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":"Intelligent classification of ballast bed defects using a bimodal deep learning model","authors":"Junjie Bu ,&nbsp;Guoqing Jing ,&nbsp;Xujie Long ,&nbsp;Lei Wang ,&nbsp;Zhan Peng ,&nbsp;Yunlong Guo","doi":"10.1016/j.trgeo.2024.101464","DOIUrl":"10.1016/j.trgeo.2024.101464","url":null,"abstract":"<div><div>The method of detecting ballast bed defects using ground penetrating radar (GPR) is an important method for guiding the maintenance of railway infrastructure. Currently, this technology primarily relies on time–frequency analysis to assess the condition of the ballast bed and manual interpretation of GPR images to identify defect areas and types, resulting in low automation levels. This paper proposes a bimodal deep learning classification model that enables intelligent classification of moisture and mud pumping defects in ballast beds. This model includes two channels, each processing a different data modality. One channel uses a Multilayer Perceptron (MLP) to extract features of A-scan data in the time domain. The other channel utilizes Short-Time Fourier Transform (STFT) to convert time domain signals into frequency domain signals, which are then processed by a ResNet18 to extract frequency domain features. By fusing the time and frequency features, the proposed Time-Frequency-Fusion ResNet model (TFF-ResNet) demonstrates superior performance. Experimental results show that TFF-ResNet outperforms the standalone MLP and ResNet18 models, with performance improvements of approximately 24% and 14% on the validation dataset, and 21% and 34% on the testing dataset, respectively.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101464"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on deformation characteristics and damage mechanisms of soil-red stratum soft rock mixture undergoing tunnel excavation unloading considering wetting","authors":"Shiqi Li ,&nbsp;Zhongping Yang ,&nbsp;Yuhao Gao ,&nbsp;Hongming Li ,&nbsp;Wenjie Xu ,&nbsp;Xiaoguang Jin","doi":"10.1016/j.trgeo.2024.101468","DOIUrl":"10.1016/j.trgeo.2024.101468","url":null,"abstract":"<div><div>Red stratum is widely distributed in Southwest China, and a large number of deep soil-red stratum soft rock mixed backfill areas were formed when the site was leveled by “high excavation and low filling” during the construction of mountain city in this area. Tunnels under construction inevitably go through backfill, which makes tunnel excavation under deep soil-rock mixture backfill become a common condition. Meanwhile, rainfall is frequent and concentrated in Southwest China, and the resulting wet disintegration of red stratum soft rock has a significant impact on the deformation and bearing characteristics of soil-rock mixture. As a result, it was decided in the present study to conduct a shear-unloading test on the soil-red stratum soft rock mixture, augmented by discrete element numerical simulations, to reveal the influence of wetting. This all-encompassing strategy seeks to examine the laws governing the deformation and progression of damage of the mixture, offering valuable insights into its response when subjected to unloading conditions. The findings indicate that the soil-red stratum soft rock mixture prior to and after wetting shows obvious strain hardening characteristics during the shear process. The residual strength after unloading has a linear correlation with unloading amplitude. The soil-red stratum soft rock mixture prior to wetting is loaded by the rock block bearing skeleton, and the rock block breakage is primarily caused by shear, while jointly loaded by soil and rock block in saturated sample, with the rock block breakage caused by wetting. After the unloading process, the dry sample’s bearing capacity no longer increases and eventually overall failure occurs. Conversely, the saturated sample’s bearing capacity can continue to increase and ultimately layered failure from the top to the bottom occurs. The unloading rate mainly affects the growth rate of load-bearing capacity after unloading of saturated samples.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101468"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102483","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":"Spatial and temporal changes in small-strain shear modulus of geogrid-stabilized crushed aggregate materials","authors":"Chelsey Yesnik ,&nbsp;Haithem Soliman ,&nbsp;Igor Morozov ,&nbsp;Ian Fleming ,&nbsp;Ethan Landry","doi":"10.1016/j.trgeo.2024.101457","DOIUrl":"10.1016/j.trgeo.2024.101457","url":null,"abstract":"<div><div>Geogrid stabilization can be used by transportation agencies to build durable roadways over soft subgrade soil. The performance of geogrid stabilization is highly dependent on the properties of the geogrid material, the aggregate material, and the interaction between the two materials when combined. Therefore, transportation agencies need to perform their own studies to assess the performance of geogrid stabilization for their local materials. Additionally, the current knowledge base needs to be continually expanded to a variety of aggregate-geosynthetic composites to develop performance-based design methods for geosynthetic-stabilization. This study evaluates the long-term performance of two geogrids used to stabilize a crushed aggregate material. A full-scale traffic loading system was built to simulate a full half-axle (40kN) traffic load for thousands of load cycles. Two trials were completed using the same crushed aggregate material. For each trial, two geogrid-stabilized sections, and one control section were evaluated. The performance of the test sections was monitored for 4000 load cycles by measuring surface rutting and completing multichannel analysis of surface waves (MASW) to measure aggregate stiffness. Results showed that the geogrid-stabilized sections had better long-term performance than the control sections with lower degradation of the as-built aggregate stiffness. There was good agreement amongst the MASW results, rutting measurements, and Shakedown analysis. It has been concluded that MASW is an effective method for evaluating the long-term performance of geogrid stabilization in aggregate layers with a customized instrumentation plan according to the targeted measurements.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101457"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102934","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":"Analysis of triaxial shear properties of mudstone coarse-grained soils considering penetrating erosion effects","authors":"Yunhao Chen ,&nbsp;Ling Zhang ,&nbsp;Zhaofeng Chen ,&nbsp;Zhongshu Liu ,&nbsp;Biao Luo ,&nbsp;Xianghong Ding ,&nbsp;Linrong Xu ,&nbsp;Zhixing Deng ,&nbsp;Zhiqiang Lu","doi":"10.1016/j.trgeo.2024.101469","DOIUrl":"10.1016/j.trgeo.2024.101469","url":null,"abstract":"<div><div>This investigation aims to elucidate the effects of penetrating erosion on the triaxial shear properties of mudstone coarse-grained soil (MCGS). The consolidated drained (CD) triaxial tests were conducted on medium-strong weathered siliceous MCGS specimens treated by various penetrating erosion stresses, comparing them with untreated specimens. The main outcomes are as follows: First of all, as the escalation of penetration erosion stress, peak shear strength diminishes, shear deformation intensifies, and the improved relative breakage potential <em>B</em>_r* of particles escalates, the critical state line rotates downward in the <em>p</em> − <em>q</em> plane, while it shifts downward in the <em>e</em> − (<em>p</em>/<em>p</em>_a)<em>^ξ</em> space. Meanwhile, the MCGS specimens treated by penetration erosion exhibit pronounced deterioration characteristics, and those variations induced by changes in penetrating erosion stress are more significant at low confining pressures, while these differences diminish progressively with increasing confining pressure. In addition, the structural stability of MCGS specimens was greatly affected by penetration erosion and dictates the susceptibility of MCGS to particle breakage, which in turn influences the triaxial shear features of MCGS. Furthermore, the equivalent correspondence between particle breakage and critical state under different treatments of penetration erosion enables the normalization of these test patterns, providing a foundation for developing a constitutive model that uniformly accounts for the influence of penetration erosion.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101469"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102463","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":"Quantifying the relative contributions of particle crushing and ITZ damage to the strength of cement-stabilized pervious recycled aggregate base materials: Laboratory testing and refined DEM simulation","authors":"Xiaoming Wang ,&nbsp;Yuanjie Xiao ,&nbsp;Tao Yang ,&nbsp;Yuliang Chen ,&nbsp;Zhiyong Li","doi":"10.1016/j.trgeo.2024.101480","DOIUrl":"10.1016/j.trgeo.2024.101480","url":null,"abstract":"<div><div>Driven by the sponge city initiative and zero net carbon emission strategy, recycled brick and mortar aggregates from building demolition wastes (BDWs) have emerged as partial or full substitutes for increasingly depleted natural aggregates to construct cement-stabilized pervious recycled aggregate base materials (CPRABMs). These recycled aggregates feature lower particle crush strength, greater variability, and lower durability, thus jeopardizing the long-term stability of CPRABMs. This study aimed to reveal the micromechanical mechanisms that influence the macroscopic compressive strength of CPRABMs by focusing on damage to the interfacial transition zone (ITZ) and the behavior of particle crushing. First, single-particle crushing experiments were conducted on various types of aggregates in the laboratory, along with unconfined compression tests on CPRABM specimens, to ascertain the statistical distribution characteristics of the single-particle strength and modulus, as well as the crack propagation patterns throughout the experiments. A refined discrete element method (DEM) model was subsequently constructed to simultaneously account for particle crushing and ITZ damage, quantifying the contribution rate of each component within the material to the overall strength of the specimens. The results show that the single-particle crush strength and modulus exhibit significant size effects, with their magnitudes decreasing in the order of natural gravel, recycled mortar, and recycled brick aggregates. The macroscopic compressive strength of CPRABMs is strongly controlled by the ITZ strength, but the controlling role is weakened by the increasing degree of crushing of recycled aggregates. The aggregates within the grain size range of 4.75-9.50 mm experienced the most profound particle crushing, thus necessitating a reduction in their proportion and/or replacement by natural aggregates. The maximum content of recycled aggregates is recommended to not exceed 50 %. The findings could provide theoretical basis and technical guidance for the design optimization of CPRABMs.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101480"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102927","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":"Interface friction behavior between soil and steel considering offshore pile driving process by ring shear tests","authors":"Sumin Song ,&nbsp;Ruslan Khamitov ,&nbsp;Sangseom Jeong","doi":"10.1016/j.trgeo.2024.101481","DOIUrl":"10.1016/j.trgeo.2024.101481","url":null,"abstract":"<div><div>Driven steel piles are commonly used in civil and offshore structures due to their high load-bearing capacity. The interface angle between steel piles and soils is a critical factor in determining pile foundation capacity. This study investigates the interface behavior between sand/clay soils and steel piles using ring shear tests, focusing on the impact of the Imperial College Pile (ICP) design method, which includes a driving impact simulation followed by slow testing. The results revealed that the fast-shearing stage recommended by the ICP method significantly affected the soil-steel interface behavior. Sand demonstrated varied responses based on relative density, with dilation occurring after fast shear due to particle redistribution. In contrast, clay exhibited consistent compaction. With a single slow shearing phase, the sand’s residual interface angle aligned with the CUR (2001) recommendation of 29 degrees, whereas with fast shearing pulses, higher angles were observed. For clay, the residual interface angle decreased with increasing confining pressure, regardless of the testing method, apparently due to changes in water content. These findings suggest that considering pile-driving effects by fast-shearing stage recommended by ICP method, is essential for accurate frictional behavior assessment in foundation design, especially for offshore structures.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101481"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102932","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":"MPM-FEM based numerical analysis on responses of stratum and twin tunnels to water-soil gushing","authors":"Xiao-Chuang Xie ,&nbsp;Francesca Ceccato ,&nbsp;Dong-Mei Zhang ,&nbsp;Ming-Liang Zhou ,&nbsp;Wu-Zhou Zhai ,&nbsp;Zhong-Kai Huang ,&nbsp;Xue-Liang Zhang","doi":"10.1016/j.trgeo.2024.101471","DOIUrl":"10.1016/j.trgeo.2024.101471","url":null,"abstract":"<div><div>Water-soil gushing presents significant challenges in shield tunnel engineering, notably large soil deformations and complex interactions between the tunnel structure and surrounding strata. Hence, this study proposed a comprehensive numerical analysis procedure using MPM and FEM to examine the whole-process responses of strata and twin tunnels to water-soil gushing. To tackle the difficulties in simulating large soil deformations, a two-phase MPM approach is first introduced and validated through a detailed case study, and then soil and water pressures obtained from the MPM model are transferred to a FEM model for tunnel structures by utilizing a data interface. The findings of a case study reveal that the gushing significantly affect the surrounding soils, particularly in terms of variations in pore pressure and soil stress within the flow zone, which could lead to significant changes in shear forces and bending moments of tunnel lining. A parametric study investigated the influence of gushing location on the tunnel. The results indicate that lower gushing locations in the tunnel lead to larger variations in the effective soil stress distribution and flow zone patterns, causing a more dramatic joint opening and dislocation. This study provides key insights into the evolutionary responses of the strata and tunnels due to the water-soil gushing, offering valuable guidance for designing and maintaining shield tunnels in water-rich sandy layers.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101471"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102459","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":"Simplified numerical simulation of vibrocompaction in sand","authors":"C.E. Grandas-Tavera ,&nbsp;M. Tafili","doi":"10.1016/j.trgeo.2024.101406","DOIUrl":"10.1016/j.trgeo.2024.101406","url":null,"abstract":"<div><div>Loosely deposited granular soils can be strengthened through cyclic loading, with vibrocompaction being a widely used and effective method. However, the lack of rational design methods stems from the complex interaction between soil and vibrator, as well as the inaccurate description of plastic accumulation caused by small strains in soil regions distant from the vibrator. In this work, we investigate Osinov’s hypothesis which suggests that the soil densification primarily results from numerous cycles of small-amplitude strains rather than wave propagation effects (including reflection and dispersion). In this way, the complex dynamic interaction between vibrator and soil (contact forces, large deformations around the vibrator, high frequency waves emanating from the vibrator, resonance effects, soil flow, etc.) is replaced by the effect of the vibrator on the soil: cyclic deformations applied repeatedly to the soil, with amplitudes varying both spatially and temporally. Quasi static finite element simulations using a combined hypoplastic and high cyclic accumulation model, with a prescribed field of strain amplitudes, show that the proposed simplified approach is able to qualitatively capture in-situ observations. The impact of different factors such as probe spacing, insertion depth, probe movement, and even the sequence in which the probe are driven can be reproduced by the model. The model’s predictions may complement on-line compaction control methods.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101406"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102464","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":"Application of a combined arching model in the load transfer platform of rigid inclusion system with raft through FEM evaluation","authors":"Boyoung Yoon ,&nbsp;Woojin Lee ,&nbsp;Hyunwook Choo ,&nbsp;Changho Lee","doi":"10.1016/j.trgeo.2024.101459","DOIUrl":"10.1016/j.trgeo.2024.101459","url":null,"abstract":"<div><div>This study introduces a novel combined arching model for the load transfer platform (LTP) layer beneath a rigid raft within a rigid inclusion (RI) system. RI systems with different pile configurations and different LTP layer thicknesses (<em>H_LTP</em>) were simulated via a 3-dimensional finite element method. Within the central unit cell of each case, vertical stress, horizontal stress, and lateral earth pressure coefficients were compared. The inflection points of horizontal stress were determined as the upper boundary of soil arch. Additionally, nonuniform stress distribution on the LTP layer is analyzed, revealing concentration above inclusion heads. The study identifies the relative spacing (<em>H_LTP</em> / (<em>S</em> – <em>D</em>), where <em>S</em> = inclusion spacing and <em>D</em> = inclusion diameter) as a significant parameter capturing stress variation. This study concludes by proposing a “combined arching” approach for soil arching under a rigid raft, which considers a multi-arch mechanism for uniformly distributed stress and vertical slip surface for concentrated stress.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101459"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102478","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}