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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Experimental evaluation on bearing performance of tire cell-geogrid reinforced subgrades</title>
      <link>https://trid.trb.org/View/2670022</link>
      <description><![CDATA[This study presents an experimental investigation of the bearing performance and deformation behavior of tire cell and tire cell-geogrid reinforced subgrades under static loading. Three physical models were tested: an unreinforced subgrade, a tire cell reinforced subgrade, and a tire cell-geogrid reinforced subgrade. Instrumentation, including pressure cells and strain gauges, was carefully calibrated to ensure accurate measurement of vertical stresses and reinforcement strains. The experiments quantified the effects of reinforcement configuration on surface settlement, vertical stress distribution within the reinforced zone. Results show that tire cells substantially reduced surface settlement and redistributed vertical stresses beneath the loading plate, while the addition of a geogrid layer further enhanced stress spreading and structural stiffness. Geogrid tensile strains peaked near the load center and gradually decreased outward, indicating the tensile force of reinforcement mobilization. Overall, the tire cell-geogrid system provided a more uniform stress field and higher load-bearing stiffness compared with the unreinforced or tire cell-only models. The observed synergistic interaction between tire cells and the geogrid highlights the potential of tire cell-geogrid reinforcement approach for sustainable subgrade stabilization in transportation engineering.]]></description>
      <pubDate>Tue, 12 May 2026 09:11:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2670022</guid>
    </item>
    <item>
      <title>Genetic programming-based closed-form solutions for predicting the compressive strength of cement-treated soils</title>
      <link>https://trid.trb.org/View/2670021</link>
      <description><![CDATA[This study presents closed-form predictive models for estimating the unconfined compressive strength (UCS) of cement-treated soils using two genetic programming techniques i.e., Gene Expression Programming (GEP) and Multi Expression Programming (MEP), addressing the limitations of existing closed-form predictive models that are often overly simplified, rely on a narrow set of input variables, or are tailored to specific soil types, thereby restricting their general applicability. An extended dataset comprising 328 data points was compiled from existing literature, covering both coarse- and fine-grained soils and incorporating key geotechnical and treatment-related parameters such as liquid limit (LL), fine content (FC), normalized compaction parameters (ρnorm, wnorm), cement dosage (C), curing time (T), and porosity-to-volumetric cement ratio (η/Civ). The dataset was pre-processed using min–max normalization and split evenly into training and testing sets. Through a systematic trial-and-error process, optimal configurations for GEP and MEP were identified. The optimal GEP and final MEP models demonstrated high predictive accuracy, achieving coefficients of determination (R²) of 0.86 and 0.92, respectively, and were further corroborated by low error room-mean-squared error, and mean absolute error. Closed-form mathematical expressions were derived from both models. Performance evaluation, including monotonicity and sensitivity analyses, confirmed the physical relevance of the models, with GEP showing higher physical consistency than MEP. Notably, feature importance varied between models: ρnorm was most influential in MEP, while FC had the highest impact in GEP. Overall, the developed models offer accurate and physically meaningful tools for predicting UCS in cement-stabilized soils, contributing to improved design practices in cement-soil stabilization applications.]]></description>
      <pubDate>Tue, 12 May 2026 09:11:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2670021</guid>
    </item>
    <item>
      <title>Experimental Study on the Accumulation Law of Creep Deformation in Rockfill Materials under Multistage Loading</title>
      <link>https://trid.trb.org/View/2670020</link>
      <description><![CDATA[This study investigates the coupling effect between stress loading and creep behavior in rockfill materials through a series of multistage loading creep tests using a weakly weathered granite from the Nuozhadu high rockfill dam. Specifically, the study examines the influence of different loading conditions—regular and small load increments—on subsequent creep behavior and explores the underlying accumulation law governing creep deformations. Experimental results reveal distinct patterns of creep accumulation under different loading conditions: after regular load increments, historical creep strain does not affect the subsequent creep process, necessitating the reset of current creep variables and restarting accumulation. Conversely, after small load increments, only a portion of the total creep strain—termed “hardening creep strain,” located between the yield surface of the current stress state and the yield surface expanded by creep—contributes to the hardening effect in subsequent loading. The proposed concept of hardening creep effectively explains the influence of creep on the subsequent loading-induced deformations. Building on these findings, a new accumulation law for the creep behavior of rockfill material is established, defining the current creep strain as equal to the hardening creep strain at any given moment, which induces additional hardening in the material. This law is universally applicable to creep accumulation calculations under complex loading conditions, encompassing both regular and small load increments. The interaction between the stress loading and creep behavior is mutually unified and symmetrically harmonious at the physical level, offering a comprehensive framework for understanding and predicting long-term deformation in rockfill materials.]]></description>
      <pubDate>Tue, 12 May 2026 09:11:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2670020</guid>
    </item>
    <item>
      <title>Analysis of dynamic response mechanism and control measures for tunnel crossing mountainous landslides: A shaking table test study</title>
      <link>https://trid.trb.org/View/2663878</link>
      <description><![CDATA[In seismically active mountainous regions, the dynamic response mechanisms and associated control measures of the earthquake–tunnel–landslide system (ETLS) have become a major research focus in the field of geotechnical engineering. In this study, a shock-absorbing layer (SAL) was adopted as a seismic control measure for the tunnel lining, and a physical model was developed in which the tunnel orthogonally undercrosses the main sliding surface of a landslide (TULS), and comparative seismic dynamic tests were subsequently conducted. In addition, the variational mode decomposition–Hilbert transform (VMD-HT) approach was employed to elucidate the seismic damage evolution of the TULS from the perspectives of energy distribution and frequency shift. The results demonstrate that the VMD-HT method exhibits clear advantages in the separation and extraction of the dominant frequencies of seismic signals, enabling precise decomposition of individual signal components. The dynamic failure of the TULS arises from the coupled interaction among the active movement of the sliding mass, the passive resistance of the tunnel, and seismic loading, and is characterized by a distinct four-stage evolutionary process. Among these, the concentration of shear stress along the main sliding surface is identified as the primary trigger for damage to the tunnel lining structure. With the incorporation of the SAL, the dynamic response of the tunnel lining is significantly reduced compared with the unprotected condition. The SAL effectively mitigates the energy impact of high-frequency components of seismic motions on the structure and slows the damage evolution of the tunnel lining.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663878</guid>
    </item>
    <item>
      <title>Active stability and probabilistic estimation of tunnel face in spatially variable and anisotropic soils</title>
      <link>https://trid.trb.org/View/2663873</link>
      <description><![CDATA[This study aims to develop an analytical approach for assessing the 3D active stability and failure probability of the tunnel face in spatially variable and anisotropic soils. An advanced failure mechanism based on discrete failure boundaries is first developed using the rigorous discretization technique. By taking the soil strata inclination as a priori condition, a non-stationary random field is proposed to represent the soil spatial variation. Comprehensive mathematical formulations are derived to denote the soil anisotropy. By incorporating spatially variable and anisotropic soils into the advanced failure mechanism, the critical support pressure and critical failure surface are determined to check the face stability using the limit analysis method. The proposed approach is validated through comparative analyses with analytical and numerical solutions. A systematic parametric investigation is then performed to discuss the effects of anisotropic and random field parameters on the face stability. Subsequently, the failure probability is derived under a specified supporting pressure, and a series of charts are provided to discuss the influence of random field parameters on the failure probability. The analysis results reveal that the proposed approach can be served as a reference methodology for the stability and probabilistic analysis of tunnel face under complex geotechnical scenarios.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663873</guid>
    </item>
    <item>
      <title>Image-traced flow behavior and frequency-dependent response of ballasted trackbed under dynamic loads</title>
      <link>https://trid.trb.org/View/2663870</link>
      <description><![CDATA[The continuous movement of ballast particles beneath the sleeper under long-term dynamic train loads is a primary factor contributing to the development of trackbed settlement, which becomes more pronounced under high-speed train operations. However, due to the concealed nature of such phenomenon, it is challenging to observe experimentally. In this study, a full-scale model test incorporating image-assisted measurement techniques was conducted. Approximately 1000 dyed ballast particles of varying sizes were uniformly distributed over a representative section of the trackbed as tracer particles. A combination of digital and high-speed cameras (recording at 1000 frames per second) was used to capture and analyze the trajectories of ballast particles under varying train speeds, axle loads and long-term loading conditions. The testing results indicate that the ballast layer remained in a stable state with limited particle migration when the loading frequency was below 15 Hz (equivalent to 273 km/h). However, once this threshold was exceeded, ballast migration increased sharply, accompanied by a noticeable loss of stability. Furthermore, a positive correlation was observed between the axle load amplitude and the extent of ballast flow. For axle loads below 8 tons, ballast migration was primarily governed by contact forces between the ballast particles. Beyond this limit, movement near the sleeper end increased sharply, indicating a shift in the controlling mechanism from contact force dominance to interaction between contact forces and boundary constraints. The varying constraint conditions then caused regionalized flow pattern beneath the sleeper, leading to non-uniform compaction within the trackbed. Furthermore, this process induced a characteristic periodic settlement development of the sleeper. The initial stage was marked by rapid settlement due to particle rearrangement. This was followed by a second increase in the settlement rate as the high-frequency energy input caused the particle skeleton to disintegrate. Finally, as a new stable skeleton formed, the settlement approached a shakedown state without further significant development.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663870</guid>
    </item>
    <item>
      <title>Numerical investigation of train-induced ground vibrations in ballastless embankments considering wheel–rail geometric nonlinearity</title>
      <link>https://trid.trb.org/View/2663869</link>
      <description><![CDATA[Predicting train-induced ground vibrations is essential for assessing the environmental impact of high-speed rail systems. However, many existing numerical models rely on simplified wheel–rail interaction formulations, which can lead to unreliable predictions due to inaccurate representation of the excitation source. In this study, a novel three-dimensional (3D) Vehicle–Track–Embankment–Ground (VTEG) finite element (FE) model is developed, explicitly incorporating rail irregularities and fully coupled wheel–rail geometric interaction. The proposed model is validated against field measurements in terms of subgrade dynamic soil stresses and ground surface vibration velocities. A parametric case study identifies two characteristic velocities. Critical Velocity I (CV I) closely corresponds to the Rayleigh wave velocity of the weakest supporting soil layer, whereas Critical Velocity II (CV II), associated with the peak maximum dynamic displacement (MDD) of track, lies between the Rayleigh wave velocities of the softest ground layer and the embankment base. Comparative analyses show that a conventional 2.5D linear FE model provides adequate accuracy under weakly dynamic conditions (V ≤ CV I) but progressively underestimates the track MDD as train speed approaches CV II. At CV II, the peak MDD is underestimated by approximately 14.6% relative to the proposed 3D nonlinear model, with about 54% of this discrepancy attributable to reduced model dimensionality and the remaining 46% to linear wheel–rail contact assumptions. Furthermore, foundation reinforcement markedly increases both CV I and CV II and reduces the peak MDD by approximately 43.5%, thereby effectively mitigating resonance-like behaviour at ultra-high train speeds. In addition, foundation reinforcement significantly suppresses ground-borne vibrations and modifies the characteristics of surface wave propagation, producing more circular wavefronts within the reinforced zone while maintaining Mach-cone-type features outside. These findings provide quantitative guidance for vibration assessment, modelling strategy selection and mitigation design in high-speed railway engineering.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663869</guid>
    </item>
    <item>
      <title>Consolidation of unsaturated composite foundation with permeable short piles and impermeable long piles</title>
      <link>https://trid.trb.org/View/2663858</link>
      <description><![CDATA[Multi-pile composite foundation technology is widely used to reinforce layered unsaturated ground. In such foundations, impermeable piles enhance bearing capacity, while permeable piles accelerate consolidation. The integration of long and short piles provides improved construction adaptability and cost efficiency over single pile configurations. However, given that most natural soils exist under unsaturated conditions, the consolidation characteristics of foundations with mixed pile types remain insufficiently understood under such conditions. This study introduces a consolidation model with a centrally located permeable short pile (PSP) surrounded by impermeable long piles (ILP). Under the assumption of equal strain, governing equations are formulated to analyze the consolidation characteristics of unsaturated composite foundations with PSP and ILP. The Laplace transform and transfer matrix technique are used to obtain semi-analytical solutions for excess pore pressures and settlement. Subsequently, time-domain analytical solutions for excess pore air pressure (EPAP), excess pore water pressure (EPWP), and settlement are obtained using Crump’s method. The accuracy of these solutions is validated by comparison with degeneration methods and numerical simulations. Finally, the consolidation performance of the PSP-ILP foundation is examined through parametric studies. The results indicate that increasing the length ratio of PSP to ILP, as well as enhancing the area replacement ratios and compression moduli of both pile types, significantly accelerates the dissipation of excess pore pressures and reduces overall settlement. Furthermore, variations in ILP parameters exert a more pronounced influence on the consolidation behavior than those of the PSP.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663858</guid>
    </item>
    <item>
      <title>Numerical investigation of electrokinetic geosynthetics-assisted vacuum preloading combined with electroosmosis for consolidation and remediation of dredged sediments</title>
      <link>https://trid.trb.org/View/2663857</link>
      <description><![CDATA[The combination of vacuum preloading and electroosmosis (VPE) enables simultaneous consolidation and remediation of dredged sediments, supporting the sustainable development of global dredging industry. However, the lack of a coupled model for dredged sediments improvement under VPE has become an obstacle to the optimisation of VPE. Therefore, a coupled model integrating electrical, hydraulic, mechanical, and chemical fields was established in this study. The numerical simulations using different consolidation equations were compared with the experimental results, including electric field intensity, excess pore water pressure, settlement, and Cu concentrations. The results indicated that the adoption of Biot’s consolidation equation in the coupled model enabled a more accurate prediction of dredged sediments consolidation and remediation performance. The numerical simulations further revealed that a lower electric potential combined with a longer treatment time resulted in a more uniform treatment effect, whereas a higher electric potential combined with a shorter treatment time accelerated Cu removal. The removal of pollutants in the deeper dredged sediment layers was markedly enhanced as the applied vacuum pressure increased. An early intervention of vacuum pressure enhanced the consolidation of dredged sediments; however, this effect gradually diminished as the treatment progressed.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663857</guid>
    </item>
    <item>
      <title>Frost Heave Characteristics of Qinghai–Xizang Silty Clay: Experimental and Numerical Modeling</title>
      <link>https://trid.trb.org/View/2667267</link>
      <description><![CDATA[The station platforms of the Qinghai–Xizang Railway are subject to persistent frost heave due to severe cold, large temperature fluctuations, and groundwater-rich conditions. To investigate the governing mechanisms and evaluate mitigation strategies, a one-dimensional thermal–hydraulic coupled freezing system was developed, and staged freezing tests with unconfined water replenishment were conducted on silty clay from Chumar River Station. Three mitigation measures—conventional geomembrane, composite geomembrane, and a 20  mm gravel isolation layer—were assessed. The results show that frost heave is primarily driven by the migration of unfrozen water toward the freezing front, where a moisture-enriched zone forms and segregated ice lenses develop. After freezing, the water content below the freezing front becomes nearly uniform, while the upper soil exhibits a unimodal increase due to moisture redistribution. Among the mitigation measures, the composite geomembrane is the most effective, reducing the frost heave ratio by 5.81%, followed by the conventional geomembrane (5.21%) and the gravel isolation layer (2.12%). Numerical models successfully reproduce the observed variations in temperature, moisture, and displacement. These findings provide practical guidance for mitigating frost heave at station platforms along the Qinghai–Xizang Railway.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2667267</guid>
    </item>
    <item>
      <title>Mechanical responses and reinforcement assessment of non-typical in-situ enlargement for closely spaced tunnel groups in weak surrounding rock</title>
      <link>https://trid.trb.org/View/2667258</link>
      <description><![CDATA[In weak surrounding rock, the closely spaced tunnel group in this study adopts a downward in-situ enlargement restricted to the overlapping segment between the existing and the new tunnels, where the interaction of evolving excavation paths and construction sequences markedly amplifies deformation and stability challenges. To examine the applicability of a non-typical stepwise “remove–backfill–downward enlargement” scheme (hereafter abbreviated as fill–then-excavate) for such settings, an ongoing closely spaced tunnel group in weak surrounding rock project along the new Chengdu–Chongqing Central Line was investigated. Laboratory tests were performed to characterize the mechanical behavior of mudstone interbedded with sandstone, and numerical simulations were integrated with in-situ monitoring to compare ground and structural deformations. Alternative backfilling strategies prior to enlargement and reinforcement options for the inter-tunnel rock pillar were assessed for construction optimization. Results indicate that stress–strain curves remain similar in shape across confining pressures, while triaxial strength and deformation characteristics vary markedly; bedding and sand-lens heterogeneity leads to pronounced mechanical anisotropy. Rightward advancement after backfilling induces early unloading in the upper-right transition zone, shifting the settlement center toward the upper-right and forming an asymmetric, unimodal pattern aligned with the enlargement contour. Excavation of the upper-bench core triggers a jump in circumferential displacement around the enlarged tunnel, with a peak of 7.79 mm. Distinct backfilling schemes perturb the surrounding rock at different stages and thereby affect both surface and lining deformations; the full backfill followed by unified enlargement scheme reduces crown settlement by 3 mm. Moreover, small-pipe grouting lowers crown settlement by approximately 20%, raises the cumulative vertical stress at the core of the middle rock pillar to 3.77–4.43 MPa, and—with simple procedures and low disturbance—emerges as a preferred option for reinforcing the pillar in closely spaced tunnels within weak rock.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2667258</guid>
    </item>
    <item>
      <title>A digital-twin LiDAR simulator for performance assessment of railway ballast geometry inspections</title>
      <link>https://trid.trb.org/View/2667257</link>
      <description><![CDATA[High-speed railways are increasingly preferred for medium-distance travel, thanks to their efficiency and convenience. However, the growing frequency of services accelerates infrastructure wear, raising inspection and maintenance demands. To address this, autonomous inspection solutions based on LiDAR (Light Detection and Ranging) systems and onboard cameras have recently been proposed, but their testing and deployment remain challenging due to regulatory constraints and the difficulty of accessing representative railway environments. This work presents a LiDAR digital twin that realistically replicates sensor behaviour in real railway track environments. The simulator incorporates CAD (Computer-Aided Design) models of the track vehicle and sensor installation, enabling the assessment of installation-related limitations and sensor field-of-view occlusions. Two commercial sensors, the Livox Avia and Livox HAP, were metrologically calibrated using experimental data acquired on a real railway track. Good agreement between simulated and experimental data was observed, with deviations of only ≃2 points/cm2 in point density and centimetre-level differences in reconstructed ballast geometry. The digital twin was subsequently used to assess the suitability of this technology for ballast geometry measurement at different travel speeds, showing centimetre-order errors for both sensors at speeds of up to 120 km/h.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2667257</guid>
    </item>
    <item>
      <title>Influence of interface flow field on slope deterioration mechanism under freeze–thaw cycles: insights from physical model testing</title>
      <link>https://trid.trb.org/View/2667256</link>
      <description><![CDATA[The process of forced convection heat transfer at the atmosphere-soil interface modifies thermal boundary conditions, thereby influencing internal thermo-hydro-mechanical (THM) responses and triggering progressive slope instability. While existing studies on freeze–thaw-induced slope deterioration either employ natural convection boundary or conductive heat transfer boundary to investigate soil responses, yet the effects of forced convection on slope degradation processes have rarely been considered. To address this gap, a novel freeze–thaw cycling apparatus was developed to simulate convective heat transfer boundaries at the atmosphere-soil interface. Physical model tests were conducted under two distinct flow fields characterized by different convection directions: upper-blowing (UB) and lower-blowing (LB), wherein the airflow is applied at the upper and lower regions of the slope, respectively. Results indicate that the rate of temperature variation in the shallow soil layer subjected to forced convection is nearly an order of magnitude higher compared to natural convection, leading to accelerated freezing front migration and the initiation of shallow cracks. These cracks gradually evolve into shallow transverse tensile fractures and deep multi-layered slip surfaces. The direction of convection alters the THM response within the slope, ultimately controlling the slope failure process: Upper-blowing flow fields generate non-uniform conditions that activate crest-originated ratcheting effects, inducing downward arcuate sliding failures, whereas lower-blowing flow fields create quasi-uniform temperature gradients that suppress localized stress concentrations, resulting in stepwise potential slip surfaces parallel to the slope. This study underscores the importance of accurately modeling the atmosphere-soil interface for slope maintenance and hazard mitigation in cold regions.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2667256</guid>
    </item>
    <item>
      <title>X-ray CT-based investigation of mesoscopic pore structure and macro-meso coupled damage model for anisotropic lean clay under a freeze–thaw cycle</title>
      <link>https://trid.trb.org/View/2667387</link>
      <description><![CDATA[The mechanical properties of frozen soil in different orientations significantly affect both the strength of frozen walls and the stability assessment of subway shield-driven tunnels constructed through geological formations using artificial ground freezing (AGF) techniques. Given that such differences resulted from depositional conditions and the arrangement of skeleton particles within clay soils, it is essential to investigate the effect of anisotropy on the strength characteristics of sedimentary clay. This study investigates the influence of inherent anisotropy and freezing temperature on the mechanical characteristics of frozen lean clay. To reduce the randomness, discreteness inherent and improve repeatability in undisturbed soil sampling, an apparatus and its methodology were developed to prepare anisotropic clay specimens with controlled sampling angles (0°, 30°, 45°, 60° and 90°). Uniaxial compressive strength (UCS) tests were conducted under varying subzero temperatures, and results showed that UCS exponentially increased with the decreasing sampling angles. Three-dimensional (3D) computed tomography (CT) scanning technology was employed to reconstruct the pore structure of specimens, revealing the lowest porosity along the natural sedimentation direction and a nonlinear trend with the increasing sampling angle. Pore parameters, including equivalent radius, throat length, and coordination number, followed a normal distribution and exhibited obvious sampling angle-dependent variations. Furthermore, the influence of freeze–thaw (F–T) cycles on UCS, elastic modulus and porosity were quantified. The damage parameters were extracted using macroscopic elastic modulus and microscopic fractal dimension as independent variables, and a coupled macro-meso damage model was established. These findings provide an effective means to quantify the degree of deterioration in soils subjected to one F–T cycle, offering a precise basis for strength parameter determination, which is essential for structural safety design and stability evaluation in AGF-reinforced engineering applications.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2667387</guid>
    </item>
    <item>
      <title>Small-scale test on the response of adjacent piles caused by shield tunnel excavation in sand</title>
      <link>https://trid.trb.org/View/2667382</link>
      <description><![CDATA[Additional settlement and stress of the surrounding high-rise buildings, bridges, high-speed railways and other pile-supported structures will be caused by the excavation process of shield tunnel, and there is a need to evaluate the influence of tunneling excavation on adjacent pile-supported structures and surrounding soil. This paper presents a small-scale test for the response of adjacent piles with different pile lengths, diameters, and pile-tunnel relative positions caused by tunnel excavation in sand. A testing machine for the precise simulation of shield tunneling process was developed, and the concrete piles of different specifications were made. The data on the displacement of surrounding sandy soil and axial force of adjacent piles induced by tunnel excavation were collected and analyzed by utilizing specially designed sensors and data collection and analysis software. Furthermore, the influence of pile length, pile diameter, pile-tunnel relative distance, and pile head load on surrounding sandy soil’s displacement caused by tunnel excavation was revealed, and the variation of axial force of adjacent piles caused by tunnel excavation with different pile lengths, pile diameters, and pile-tunnel relative distances was clarified. The relevant achievements can provide scientific guidance and practical support for disaster prevention and control of adjacent in-service piles during tunnel excavation in sand.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2667382</guid>
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