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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
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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>Drag embedment anchor penetration in layered sands and through cable and pipeline trenches</title>
      <link>https://trid.trb.org/View/2725457</link>
      <description><![CDATA[Cable Burial Risk assessment (CBRA) is undertaken to identify risks to offshore renewable energy cable infrastructure. CBRA assumes uniform soil conditions and does not recognise the effect of the cable installation methods. Centrifuge model testing was undertaken to explore the performance of a shipping anchor (AC-14) when encountering layered sand soil profiles. In addition, anchor interaction with both cable plough trenches and backfilled V-shaped pipeline plough trench routes were investigated. For a specific anchor, in loose over dense sand layers, penetration is stopped with minimal penetration into the underlying dense layer irrespective of the thickness of the loose layer for the anchor size investigated. Testing a recent layered soil CBRA approach indicated that it performed well when inputs were based upon well-characterised model anchor performance. Anchor interaction with vertical cable plough trenches showed limited modification of anchor behaviour. Similar observations were made for the V-shaped backfilled trenches where the anchor approached at 90 or 45° to the trench. When the anchor followed the route of the trench it dived through the trench and backfilled material and into the underlying dense soil. For CBRA methods to improve there is a need for high-quality characterisation of different anchor types in a wider range of soil conditions where realistic installation practices are considered.]]></description>
      <pubDate>Mon, 27 Jul 2026 09:46:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2725457</guid>
    </item>
    <item>
      <title>Load carrying capacity of strip foundations on layered unsaturated soil media</title>
      <link>https://trid.trb.org/View/2692504</link>
      <description><![CDATA[Foundations are the primary structural elements that transfer loads from a superstructure to the underlying soil. Since structures are subjected to various forces, ensuring the stability of foundations is of critical importance. Most existing studies, however, have considered foundations resting either on fully dry or fully saturated soils, thereby neglecting key factors such as matric suction. Even in studies that address unsaturated conditions, the soil is typically assumed to be homogeneous. Field conditions often involve layered soil deposits, for example, clay over sand in riverbanks and floodplains, lacustrine (lake) deposits, or residual soil profiles formed from weathered rock. This study investigates the stability of a strip foundation on a layered unsaturated clay-sand medium. The numerical approach for determining the bearing capacity integrates lower bound theory, the finite element method, and second-order conic optimization. The analysis primarily explores the influence of foundation width, water table depth, depth of the clay layer above the sand layer, clay cohesion, internal friction angle of clay, and flow conditions. Additional parameters such as van Genuchten soil water retention properties, saturated unit weight of the layers, soil-foundation interface friction angle, and soil specific gravity are also examined. The outcomes are expressed in terms of a non-dimensional bearing capacity factor, and representative failure patterns are presented for selected cases.]]></description>
      <pubDate>Thu, 23 Jul 2026 09:14:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2692504</guid>
    </item>
    <item>
      <title>Prediction of Efficiency Factor of Strip Footing on Layered Soil Using Machine Learning Techniques</title>
      <link>https://trid.trb.org/View/2684134</link>
      <description><![CDATA[This study utilizes three machine learning (ML) models, namely artificial neural network (ANN), Gaussian process regression, and adaptive boosting, to predict the efficiency factor of a strip footing resting on layered soil. 400 datasets with six input variables, including the angle of shearing resistance of the upper and lower soil layer, the unit weight of upper and lower soil layers, the depth of the footing, and the thickness of the upper soil layer, were used to compute the output. To legitimize the precision of these ML models, different performance parameters were used. These performance parameters include coefficient of determination (R²), variance account factor, performance index, root mean square error (RMSE), mean absolute error, and maximum absolute error. Results showed that the ANN model had the most suitable outcomes among these three ML models, with the highest R² = 0.988 and the lowest RMSE = 0.02 in the training phase, and R² = 0.964 and RMSE = 0.035 in the testing phase, respectively. The first-order second moment technique was used to compute the reliability index. The efficacy of the models was also checked by using score analysis, regression plots, William’s plots, external validation, and comparative analysis. Sensitivity analysis was carried out to check the influence of each input parameter on the output.]]></description>
      <pubDate>Wed, 29 Apr 2026 17:05:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2684134</guid>
    </item>
    <item>
      <title>Mapping the Underground: Geotechnical Physical Properties Insights from Bengkulu City</title>
      <link>https://trid.trb.org/View/2645991</link>
      <description><![CDATA[This study presents a three-dimensional engineering geology model of soil-layer physical parameters in Bengkulu City, Indonesia. The model provides an integrated understanding of the subsurface profile to support construction design and planning. Three-dimensional modelling is applied to identify subsurface geological layers and visualize key soil physical properties using colour-scaled parameter distributions. The analysed parameters include shear wave velocity, plasticity index, saturated unit weight, bulk unit weight, dry unit weight, water content, and degree of saturation. Data interpolation is performed using the Inverse Distance Weighting method, which is suitable for estimating parameter continuity within layers in 3D geological modelling. The resulting model identifies five generalised subsurface layers: sand, clay, soft rock, medium rock, and hard rock. Interpolated parameter variations are illustrated through geological profiles and Probability Density Function plots, enabling more straightforward interpretation of value distributions across the study area. Overall, the findings offer practical insights and essential baseline information for engineers and planners conducting soil investigations in Bengkulu City.]]></description>
      <pubDate>Mon, 26 Jan 2026 08:41:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2645991</guid>
    </item>
    <item>
      <title>Reassessment of post-construction residual settlement of a bridge approach embankment using Bayesian back analysis</title>
      <link>https://trid.trb.org/View/2592547</link>
      <description><![CDATA[As part of a highway upgrade project in northern New South Wales, Australia, a bridge was constructed over deep soft soils improved by preloading and prefabricated vertical drains (PVDs). Shortly after the bridge opened to traffic, the bridge approach slab settled beyond the serviceability limit. Although slab jacking was implemented, subsequent monitoring revealed settlement again exceeded the predicted upper bound, prompting a reassessment of long-term residual settlement and mitigation strategies. However, this reassessment is challenged by discontinuous monitoring data, instrumentation changes and uncertainty in settlement offsets. Early settlement measurements (May 2017 to February 2018) were taken away from the final embankment location due to a design-stage realignment that shifted the southern abutment. Monitoring was halted during abutment construction and resumed from July 2019. To overcome these challenges, a Bayesian back analysis framework was adopted to calibrate both dataset offsets and soil parameters. The analysis showed that using only the post-construction monitoring data provides the closest fit to the measurements and a reliable prediction of the ongoing settlement growth. The predicted residual settlement over the service life ranges from 306 to 444 mm, with an average value of 385 mm. Sensitivity analyses indicate that slight variations in fill unit weight, due to heavy compaction, and in soft soil thickness, influenced by bridge realignment, have limited impact on settlement predictions due to compensating effects within the Bayesian model. This study also demonstrates the value of probabilistic approaches for assessing long-term settlement under data discontinuities and soil uncertainty, providing insights for similar infrastructure projects.]]></description>
      <pubDate>Thu, 16 Oct 2025 17:02:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2592547</guid>
    </item>
    <item>
      <title>Influence of Soft Clay Depth and Thickness on the Combined Axial and Lateral Response of Bored Piles: A Numerical and Field Investigations</title>
      <link>https://trid.trb.org/View/2526575</link>
      <description><![CDATA[This paper investigates the behavior of reinforced concrete bored piles embedded in layered soils containing a soft clay layer under both axial and lateral loading. Experimental data from full-scale pile load tests, conducted on 0.6 m diameter and 16 m long piles, were used to validate a three-dimensional finite element model employing the Modified Mohr-Coulomb soil model. The validated model was then used to perform a parametric study, varying the depth and thickness of the soft clay layer. The results show that increasing the thickness of the soft clay layer significantly increases the settlement of axially loaded piles. In contrast, the depth of the soft clay layer from the ground surface had a negligible effect on the settlement. The soft clay layer’s depth critically influences the piles’ lateral response, with shallower depths (within five times the diameter of the pile) leading to increased lateral deflection and bending moments. A stiffer soil layer above the soft clay mitigates these adverse effects. Furthermore, the study reveals a significant interaction between axial and lateral loading. These findings underscore the importance of considering the depth and thickness of soft clay layers and the combined effects of axial and lateral loading in the design of pile foundations. The validated numerical model provides a valuable tool for predicting pile behavior in complex soil conditions, contributing to more efficient and reliable pile foundation designs.]]></description>
      <pubDate>Thu, 03 Apr 2025 09:07:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2526575</guid>
    </item>
    <item>
      <title>Vibration of the track-soil system due to a harmonic moving load on railway tracks resting on layered soils by 2.5D approach</title>
      <link>https://trid.trb.org/View/2509461</link>
      <description><![CDATA[Research on the vibrations of track-soil coupling system has been enhanced by the rapid construction of high-speed railways worldwide. As part of the effort to address this problem, a dynamic analysis model composed of the track and soil subjected to a harmonic moving load is analyzed by the 2.5D approach. Focus is placed on the response of the track-soil system caused by the harmonic moving load at sub-critical, critical, and super-critical speeds. The track is modeled as a three-layered structure comprising the rails, sleepers and ballast and the underlying soil is simulated by the 2.5D finite and infinite elements. The train load is treated as a single moving load oscillating with self frequency f₀. A thorough investigation is presented for the effects of the moving load with various self frequency f₀ at the sub-critical, critical, and super-critical speeds on the ground response. In addition, the effects of the rail and soil properties on the rail response were assessed, as well as on the differential responses of the rails and the ground. The findings of the paper include: (1) The critical speed of the soil is deeply affected by the material properties of the soil and the track, as well as the self frequency f₀ of the load. Particularly, using a stiffer soil or a lighter track helps to mitigate the ground response, while increasing the critical speed ccr. (2) A decrease in the shear wave speed ratio of the soil tends to enhance the fluctuation of the ground vibration. At zero self-frequency, increasing soil layer depth H may increase the maximum displacement, while decreasing the vibration fluctuation; as the self-frequency f₀ rises, the effect of soil layer depth H on ground response further diminishes. (3) An increase in the self frequency f₀ of the moving load tends to decrease both the ground response and the level of fluctuation. (4) The higher-frequency rail response for a lighter track on stiffer soils is pronounced prior to arrival of the load at t = 0 s, while the lower-frequency rail response for a heavier track on a softer soil is more significant after t = 0 s.]]></description>
      <pubDate>Wed, 26 Mar 2025 16:37:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2509461</guid>
    </item>
    <item>
      <title>Three-Dimensional Slope Failure Response Based on Limit Equilibrium Method</title>
      <link>https://trid.trb.org/View/2437733</link>
      <description><![CDATA[Three-dimensional slope stability study is preferable to 2D stability assessments since all slopes are three-dimensional. Based on 3D extensions of the ordinary slice method and simplified Bishop’s method, this study presents 3D slope stability analysis results for homogeneous and heterogeneous soil slopes. The geometry of the slope is built with the help of the Digital Elevation Modelling (DEM) technique. Both the ordinary column method (OCM) and simplified Bishop’s method (SBM) in 3D satisfy the moment equilibrium of the failure mass. The obtained FS values for all three problems match the published results closely. The effects of pore water pressure applications and seismic loadings are further investigated by considering different combinations. The pore pressure ratio and horizontal seismic coefficient, with values ranging from 0.25 to 0.50 and 0.05 to 0.10, respectively, have been considered in the present analysis. The detailed variations of normal and shear forces acting on the base of the 3D columns, as well as the variations of other important parameters such as true dip angle and apparent dip angles along the longitudinal and lateral direction of the failure surface, are shown to highlight the mechanisms of generation of internal forces inside the failure mass, both along longitudinal and lateral directions of the slope. The plots of normal and shear forces along the longitudinal direction of the slope follow a symmetric distribution. In contrast, these plots along the lateral direction of the slope follow an asymmetric profile. It is further seen that when pore pressure and earthquake forces are considered, the normal forces increase, and the mobilised shear forces decrease along both longitudinal and lateral directions of the 3D slope.]]></description>
      <pubDate>Wed, 09 Oct 2024 10:20:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2437733</guid>
    </item>
    <item>
      <title>Analytical method for free vibration of steel pipe piles partially submerged in water and penetrated in layered soil</title>
      <link>https://trid.trb.org/View/2420490</link>
      <description><![CDATA[This paper presents a novel analytical method for dynamic characteristics of steel pipe piles submerged in water based on the thin shell theory by using the state space method. The state equation with respect to the length direction is first derived by idealizing the steel pipe pile in water as a thin cylindrical shell, where the soil around the pile is modelled as an elastic foundation with stiffnesses in three directions and the surrounding seawater is considered through added equivalent mass. The governing equations for the free vibration of steel pipe piles are derived after the expansion of Fourier series for the state vectors along the circumferential direction. The frequency equation for free vibration and its corresponding mode shapes are then obtained, which is used to analyze the dynamic characteristics of steel pipe piles in water. Due to the advantage of the state space method, arbitrary boundary conditions of the steel pipe pile are conveniently achieved as well as the effects of seawater, soil, the piling hammer and guiding frame. Finally, the present analytical method is verified and demonstrated in detail by several numerical examples, and results show its simplicity and efficiency.]]></description>
      <pubDate>Wed, 28 Aug 2024 17:20:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2420490</guid>
    </item>
    <item>
      <title>Deep Learning–Based Prediction of Tunnel Face Stability in Layered Soils Using Images of Random Fields</title>
      <link>https://trid.trb.org/View/2387377</link>
      <description><![CDATA[The stability analysis of tunnel faces in multilayered soils presents challenges due to the inherent variability in natural soils. Although the random field finite-element methods offer a reliable approach to address such variability, their heavy computational demands have been a significant drawback. To overcome this limitation, this study presents a novel deep learning–based method for efficient tunnel face stability analysis in layered soils with spatial variability. By combining the merits of convolutional neural networks (CNNs) and U-Net, the proposed method trains surrogate models using a small but sufficient number of random field images to effectively learn high-level features that encompass spatial variabilities, which significantly enhances computational efficiency. In particular, U-Net generates precise displacement field images based on random field images, enabling the discrimination of tunnel face collapse failure modes. To validate the effectiveness of this proposal, a comprehensive case study involving layered soils with spatial variabilities is conducted. The remarkable agreement between the outputs of CNNs and U-Net and the predictions of finite-element simulations underscores the promising potential of using deep-learning models as a surrogate for analyzing the stability of tunnel faces in spatially variable layered soils. Last but not least, the key innovation of this work lies in the pioneering application of U-Net for geotechnical reliability analysis.]]></description>
      <pubDate>Fri, 12 Jul 2024 10:56:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2387377</guid>
    </item>
    <item>
      <title>Behavior of Laterally Loaded Piles Installed in Layered Soils with a Soft Clay Layer</title>
      <link>https://trid.trb.org/View/2366829</link>
      <description><![CDATA[This paper presents the behavior of a laterally loaded concrete bored pile installed in layered soils with a soft clay layer using a full-scale pile load test and the finite element analysis. The first part of the study consisted of conducting a full-scale pile load test. A three-dimensional finite element model was developed and compared with the results of the full-scale pile load test. The numerical model showed good agreement with the results of the full-scale test. Parametric studies using the numerical model showed that the deformations of the laterally loaded piles depend on the location of the soft clay layer below the ground surface. The lateral deformations increase significantly with the thickness of the soft clay layer when the soft clay layer is within 5 times the pile diameter below the ground surface. Stiffer soil above the soft clay reduces the lateral deformation compared to the case where the soft clay layer extends from the ground surface.]]></description>
      <pubDate>Fri, 10 May 2024 16:50:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2366829</guid>
    </item>
    <item>
      <title>Consolidation of multilayered soil with fractional derivative viscoelasticity due to surface loading and internal pumping</title>
      <link>https://trid.trb.org/View/2227575</link>
      <description><![CDATA[Classical Terzaghi’s solution provides a useful tool to predict the one-dimensional consolidation of homogeneous elastic soil layer with fully drained/undrained boundary condition under instantaneous loading. Due to the sedimentation process and complex internal structure, natural soils usually exhibit multilayered inhomogeneity and viscoelastic behavior. In practical cases, the drainage capacity of the boundaries can change with time. Thus, these practical factors should be well in considered for accurate prediction of the consolidation. This paper extends the classical Terzaghi’s solution to multilayered viscoelastic soil with continuous drainage boundaries and subjected to time dependent loading. The fractional derivative Kelvin-Voigt model is used to describe the viscoelasticity of soil. Two loading cases namely surface loading and internal pumping are considered. The consolidation problem is solved by Laplace transform technique and a transfer matrix formulation. Analytical solutions for excess pore water pressure, effective stress and settlement are given. The present solution is general and can reduce to existing solutions available in the literatures. Numerical studies are conducted to investigate the effects of viscoelastic parameters, boundary drainage capacity and loading rate on the consolidation behavior. It is shown that the multilayered soil system with large viscosity coefficient and small fractional order can consolidate fast. For the consolidation due to internal pumping, the drainage parameters have no influence on the consolidation process.]]></description>
      <pubDate>Mon, 28 Aug 2023 17:10:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2227575</guid>
    </item>
    <item>
      <title>A New Approach to Estimate Bearing Capacity of Strip Footings on Geogrid-Stabilised Granular Layer over Clay</title>
      <link>https://trid.trb.org/View/2211510</link>
      <description><![CDATA[In this study, the finite element method (FEM) is used to estimate the bearing capacity of strip footing on a non-stabilised and geogrid-stabilised granular layer over clay. The FEM model was developed using ABAQUS software that accommodates a range of angles of internal friction and thicknesses of overlying stronger granular layer and strength of underlying weaker clay layer. The results are used to develop design charts with dimensionless parameters in terms of linear-gradient (m) and the ratio of undrained shear strength of clay to effective vertical stress at the base of the granular layer (c[subscript u]/p[subscript 0]). The proposed charts also contain trend lines with simple power-rule equations for different angles of internal friction of the granular layer. The charts are validated and compared with the published results in the literature and found to be closely similar. A design example is provided to illustrate the comparison of the design curves and to benchmark with other established design methods. The comparative results reveal that the proposed approach yields a comparable outcome and predicts reasonable bearing capacity. Moreover, the developed design charts and the associated equations are relatively simple and easy to use. A typical result of the analysis indicates that the use of a geogrid-stabilised granular layer provides a capacity improvement factor (CIF) of 1.1 to 1.6 depending on the soil parameters and the thickness of the granular layer.]]></description>
      <pubDate>Wed, 23 Aug 2023 10:14:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2211510</guid>
    </item>
    <item>
      <title>Numerical Estimation of Bearing Capacity of Shallow Footings Resting on Layered Sand</title>
      <link>https://trid.trb.org/View/2211509</link>
      <description><![CDATA[In the present study, estimation of bearing capacity of strip footing and circular footing resting on layered sand following the non-associated flow rule (ψ < ϕ) is carried out by finite element analysis. This study provides insight into the variation of bearing capacity at the failure of the footing with change in footing’s shape, dense sand layer’s thickness, and friction angle of sand layers. The bearing capacity of footing on layered sand was expressed in terms of BCR (ratio of bearing capacity of the footing on layered sand to bearing capacity of homogeneous bottom layer). The magnitude of BCR for a selected range of friction angles was in the range of 2.48–20.28 for strip footing and 4.44–44.34 for circular footing. Furthermore, footing settlement on layered sand decreased up to 68.75% and 90.6% for strip and circular footing, respectively. The obtained results were compared with the literature wherever applicable.]]></description>
      <pubDate>Wed, 23 Aug 2023 10:14:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2211509</guid>
    </item>
    <item>
      <title>Numerical Investigations on Evolution Mechanism of Contact Erosion in Layered Soils Considering Particle-scale Parameters</title>
      <link>https://trid.trb.org/View/2173929</link>
      <description><![CDATA[Internal erosion is one of the leading causes of failures in transportation infrastructures including bridges and road embankments. For layered subsoil conditions, contact erosion may occur if the gradation of soil in different layers is not properly selected, and is controlled by the speed of inflowing water and the particle sizes. This phenomenon is difficult to observe on-site or in the laboratory and the underlying mechanism still needs to be clarified as it occurs inside the subsoil layer. This paper presents a particle-scale study that utilizes physical tests and representative volume CFD-DEM simulations to explore the contact erosion process at the interface between soil layers consisting of coarse-grained and fine-grained particles. It is first calibrated and validated by comparing the simulation results with experimental observations. Then the influences of contributing factors on contact erosion initiation and progression from the view of particle scales are analyzed. The results show that particle size ratio is a significant factor that determines the occurrence and development of contact erosion. The specific gravity of particles affects their erosion resistance, while the effect of particle friction is not obvious since the transport of fine non-cohesive particles does not involve significant particle sliding. Particle shape has a major influence on the contact erosion process. Meanwhile, the critical inflow velocity and particle size ratio for contact erosion occurrence can be determined via the coupled model presented in this study.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2173929</guid>
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