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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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <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>Three-dimensional modelling of drag anchor penetration using the material point method</title>
      <link>https://trid.trb.org/View/2711244</link>
      <description><![CDATA[Drag embedment anchors are a key threat to buried subsea linear infrastructure, such as power/data cables and pipelines. For cables, selecting a burial depth is a compromise between protecting the cable from anchor strike and the increased cost of deeper installation. This paper provides an efficient large deformation, elasto-plastic Material Point Method-based soil–structure interaction predictive tool for the estimation of anchor penetration based on Cone Penetration Test (CPT) site investigation data. The tool builds on earlier work by the authors supplemented by three key developments: modelling assemblies of rigid bodies (necessary for articulated anchors), a partitioned domain approach to enable accurate and efficient modelling of long anchor pulls, and an improved means of modelling rotational inertia. The numerical model is calibrated using CPT data and then used to predict the penetration behaviour of two different drag anchors across a range of relative density sands under drained conditions with validation against scaled geotechnical centrifuge physical tests. Numerical simulations both confirm assumptions in, and identify key issues with, the UK Carbon Trust’s Cable Burial Risk Assessment (CBRA) approach for estimating anchor penetration. In particular, the results confirm that anchor penetration scales linearly with fluke length but also that the penetration of drag anchors is highly dependent on both the relative density of the sand and the full geometry of the anchor. The numerical model presented in this paper enables site-specific anchor-penetration assessment along cable routes and can be used to evaluate the performance of different anchor designs and sizes in varied soil conditions.]]></description>
      <pubDate>Mon, 08 Jun 2026 08:37:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2711244</guid>
    </item>
    <item>
      <title>Strengthening Characteristics of Bottom Expansion and Backfilling Anchoring in Fractured Surrounding Rock Roadways</title>
      <link>https://trid.trb.org/View/2709178</link>
      <description><![CDATA[The weak anchoring force and inadequate stability of the anchoring system (AS) in fractured rock roadways frequently lead to anchor rod slip failures. To address this issue observed in a mine in Song County, this study employed a combination of theoretical analysis, laboratory experiments, numerical simulations, and field tests for a comprehensive investigation. Firstly, the study examined the load-bearing capacity, interactions between backfilling body and surrounding rock, and the force distribution exerted by the backfilling body on the surrounding rock under various bottom backfilling body shapes. The inverted wedge shape was identified as the optimal expansion configuration. Secondly, laboratory pull-out tests were conducted on anchor rods configured in three different forms. These tests aimed to compare and analyze the variations in anchoring force among the three anchoring configurations, as well as the interactions between backfilling body and surrounding rock. The results indicated that utilizing self-expanding head anchor rods for bottom backfilling and anchoring support yielded the most significant improvement in anchoring efficacy. Finally, a field test was conducted at a mine in Song County. The findings revealed that the utilization of self-expanding head anchor rods for bottom backfilling and anchoring support resulted in a transition of the surrounding rock deformation from axial to predominantly transverse. The maximum deformations of the roof, floor, and sidewalls were decreased by about 85%. The time required for the roadway to reach stability was advanced by ~150 days. Further evidence suggests that this anchoring support technology can achieve a significant increase in anchoring force with only a modest increase in engineering investment, thereby effectively ensuring the stability of the roadway.]]></description>
      <pubDate>Tue, 02 Jun 2026 13:56:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2709178</guid>
    </item>
    <item>
      <title>Design and analysis of shared anchor layouts for floating wind farms in deep waters</title>
      <link>https://trid.trb.org/View/2661539</link>
      <description><![CDATA[As floating wind farms for the U.S. West Coast are currently being explored, this study provides reference mooring system designs and anchor loads for farms with shared anchors in deep water (850 m), based on a 15 MW turbine, a size currently being deployed. It offers a comprehensive analysis of two shared anchor layouts, governed by 3-line and 6-line shared anchors, with mooring systems designed to maintain a minimum turbine spacing of 2000 m.A detailed loads analysis assesses line tensions, shared anchor forces, and force directionality under various environmental conditions. Suction caissons are designed for two soil profiles based on the loads analysis. A mooring cost analysis compares 54-turbine farm layouts with shared anchors to a baseline layout without shared anchors.Results show that while the 6-line anchor experiences higher loads due to additional platform connections, it exhibits lower inclination angles and less variability compared to the 3-line anchor. Suction caisson designs are primarily influenced by net force magnitude and inclination angle, resulting in similar dimensions for both layouts due to their higher horizontal resistance. Farms with shared anchors demonstrate mooring cost reductions of up to 36% compared to the baseline, with the 6-line layout offering the lowest mooring system costs, albeit with only marginal differences compared to the 3-line layout. Overall, this study highlights how taut mooring systems with shared anchors impact anchor loads, mooring system footprints, and overall farm layout, providing valuable insights for future deep-water floating wind projects.]]></description>
      <pubDate>Mon, 27 Apr 2026 14:57:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2661539</guid>
    </item>
    <item>
      <title>Developing failure envelopes of strip anchors under combined V-H-M loadings using FELA and ADABoost models</title>
      <link>https://trid.trb.org/View/2660820</link>
      <description><![CDATA[This paper investigates the failure envelopes of horizontal strip anchors under combined V-H-M loading conditions in both 2D (H/suTCB, M/suTCB2) and 3D (V/Vult, H/suTCB, M/suTCB2) spaces. It examines how the anisotropy strength ratio (re) and anchor embedment ratio (D/B) affect the behavior of strip anchors in clays using adaptive finite element limit analysis (FELA). Additionally, this study presents a novel soft-computing approach by developing a machine learning model that incorporates the adaptive boosting (ADABoost) technique to create surrogate models for predicting the failure envelope of horizontal strip anchors. The proposed ADABoost model is accurate and validated against the numerical FELA results, providing engineers with a practical tool for establishing the failure envelope of a strip anchor in anisotropic clay under general V‒H‒M loadings. The findings of this study are expected to contribute innovative and reliable solutions for optimizing standard strip anchors under general loading conditions.]]></description>
      <pubDate>Thu, 23 Apr 2026 09:12:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2660820</guid>
    </item>
    <item>
      <title>Numerical study on the yield surface of plate anchors in clay: Effect of soil-anchor interface tension</title>
      <link>https://trid.trb.org/View/2661444</link>
      <description><![CDATA[The growing demand for floating offshore wind turbines in deep-water environments has increased reliance on plate anchors to provide holding capacity. These anchors are subjected to combined normal, sliding, and rotational moment loadings during drag-in installation, keying processes, and long-term service as permanent mooring systems. Most previous studies have evaluated the combined loading capacity yield surface of plate anchors by assuming a fully bonded soil-anchor interface, equivalent to infinite interface tension – an assumption that may be unconservative. This study investigates the uniaxial bearing capacities and combined loading yield surfaces of plate anchors in clay under varying soil-anchor interface tension conditions using finite element modelling. A comprehensive parametric study was performed, considering embedment depth, anchor thickness ratio, anchor roughness, and, critically, soil-anchor interface tension. The results show that the yield surface evolves disproportionately in three-dimensional loading space, with pronounced enlargement in the normal direction as interface tension increases, until a critical value is reached. Parameterised design equations are proposed for the yield surface, enabling straightforward evaluation of combined loading capacities under varying interface tension conditions.]]></description>
      <pubDate>Thu, 23 Apr 2026 09:12:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2661444</guid>
    </item>
    <item>
      <title>Failure Envelopes of Helical Anchors in Sand</title>
      <link>https://trid.trb.org/View/2657930</link>
      <description><![CDATA[Helical anchors have emerged as an attractive alternative supporting offshore floating structures due to their low noise installation, high pullout capacity, and potential reusability. This paper investigates large-diameter (Dh=1–2  m) helical anchors subjected to inclined pullout at the mooring line using a critical-state-compatible bounding surface sand plasticity model (Sanisand04) within a three-dimensional finite-element (3D-FE) framework. With careful numerical implementation of the sand model, validation studies were performed with comparisons with theoretical solutions from the literature. A range of sand densities of practical interests were explored while documenting the sand state and displacements surrounding the anchor under complex V−H (vertical-horizontal) loading conditions. The model successfully captures the transition from shallow to deep failure mechanisms and provides visual evidence of the sand mobilized zone under varying mooring load angles over the range of sand densities studied. The affected zone decreases with increasing embedment depth and increases with higher relative density. A stepwise calculation framework is proposed for routine assessment of the V−H failure envelope for a single-helix anchor. An existing anchor pullout model for shallow embedment is systematically extended to deep helical anchors, allowing quick estimation of the vertical pullout capacity.]]></description>
      <pubDate>Tue, 21 Apr 2026 14:30:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2657930</guid>
    </item>
    <item>
      <title>The impact velocity of gravity installed anchors released in air at different height, added mass and scale conditions</title>
      <link>https://trid.trb.org/View/2660623</link>
      <description><![CDATA[For various types of gravity installed anchor (GIA) that rely on free fall to penetrate the seabed, it is vital before installation to accurately evaluate the velocity that the anchor impacts the seabed. However, challenges are arising when facing emerging engineering developments: (1) the GIA has to be released in air to ensure a sufficient falling distance when the water is not deep enough; (2) to enhance the penetration of GIAs in sandy seabed, auxiliary techniques are considered to apply such as adding extra mass to the anchor; (3) compared to conventional GIAs in deep waters, the GIA with smaller size is more often an option for offshore floating applications, such as renewable energy developments. To deal with the varieties and complexities in evaluating the impact velocity, a systematic study is performed to explore the effects of different factors, including the anchor type, the release heights both in water and in air, the added mass, and the anchor scale. Three typical types of GIAs, namely the finless, T98 and OMNI-Max anchors, are selected in the present study. By combing theoretical and computational fluid dynamics (CFD) analyses, a unified explicit expression of the falling velocity of GIAs is derived in terms of multiple factors, which can be simply and quickly used to calculate the impact velocity of GIAs for various applications.]]></description>
      <pubDate>Tue, 21 Apr 2026 14:30:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2660623</guid>
    </item>
    <item>
      <title>An assessment of model parameters for offshore torpedo anchors</title>
      <link>https://trid.trb.org/View/2660604</link>
      <description><![CDATA[Torpedo anchors offer a fast and cost-effective solution for floating wind turbine moorings. However, the application of torpedo anchors outside Brazil remains limited due to insufficient design guidance and uncertainty in model parameters. Therefore, the key objective of this paper is to critically assess and provide appropriate model parameters for practical design, including the hydrodynamic and geotechnical models. The paper presents the hydrodynamic model, the penetration model, and the holding capacity model separately with both existing data in the literature and new data. The key findings are: (1) an equivalent system drag coefficient of 1.0 can be used in the hydrodynamic model for predicting the anchor impact velocity in water; (2) a soil strain-rate parameter of 0.123 and an added mass coefficient of 2.0 can be used in the penetration model for predicting the anchor final embedment; (3) a closed-form failure envelope under inclined loading is assessed to be appropriate for the anchor holding capacity. Uncertainties observed in laboratory tests and field installations during the various anchor design stages are covered by the suggested low to high estimates of the model parameters for practical design. The paper ends with discussions and recommendations for current practice and future studies.]]></description>
      <pubDate>Tue, 21 Apr 2026 14:30:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2660604</guid>
    </item>
    <item>
      <title>Continuously Welded Rail Longitudinal Resistance Modeling</title>
      <link>https://trid.trb.org/View/2686808</link>
      <description><![CDATA[This research aimed to develop efficient 3D finite element (FE) models to simulate railroad longitudinal resistance in continuously welded rail (CWR). Using experimental data from the University Transportation Center for Railway Safety (UTCRS) and historical data from the Federal Railroad Administration’s (FRA's) 1997 report on CWR behavior and a 2022 FRA-sponsored study on frozen ballast conditions, the goal of this study was to replicate and predict real-world force-displacement behavior in varying rail conditions. In this regard, a parametric FE model, which consists of a 600-ft rail segment and focuses on rail–tie interaction, was developed in ABAQUS software to simulate such conditions. In a conventional railroad system, the rail is the steel element that guides train wheels, ties are horizontal supports that hold the rails in place and transfer loads, and anchors are steel clamps that attach to the rail and bear against the tie to resist longitudinal movement. This modeling approach simulates the anchors as nonlinear springs based on experimental data, enabling better predictions in untested or challenging scenarios. This project presented a unique opportunity, as UTCRS-University of Texas Rio Grande Valley (UTRGV) researchers have conducted relevant experimental work that could be directly utilized to inform and validate the finite element modeling, enhancing the accuracy and applicability of the results. The experimental setup involved a single rail segment approximately 26 inches in length mounted on a single tie with one anchor. A longitudinal load was applied to one side of the rail, while displacement was measured at the opposite end, allowing researchers to observe the railroad anchor resistance behavior under controlled conditions. These findings will aid in establishing anchor stiffness for future modeling of full rail resistance, including complex ballast conditions.]]></description>
      <pubDate>Fri, 10 Apr 2026 10:52:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2686808</guid>
    </item>
    <item>
      <title>A Case Study of Ground Anchor Effectiveness on Slope Stability in Red Basaltic Soil</title>
      <link>https://trid.trb.org/View/2680103</link>
      <description><![CDATA[This study optimizes the design of ground anchor systems to reinforce slopes in the red basaltic soil region of DaLat, Vietnam, addressing the critical risk of landslides. The Finite Element Method (FEM) and the Shear Strength Reduction (SSR) techniques are employed to investigate the effects of anchor spacing and inclination angles on the stability of slopes with varying gradients. The present findings indicate that the Factor of Safety (FoS) increases significantly as anchor spacing decreases. To achieve high reinforcement efficiency, it is recommended to prioritize spacing configurations not exceeding 4 m. The optimal inclination angle α is determined to depend directly on the slope gradient: for steeper slopes with gradients not exceeding 1H:1.5V, inclination angles ranging from 30° to 40° are recommended, whereas for gentler slopes with gradients of 1H:2V and above, higher inclination angles ranging from 40° to 45° are preferred.]]></description>
      <pubDate>Wed, 25 Mar 2026 11:44:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2680103</guid>
    </item>
    <item>
      <title>Reliability Analysis of Anchor-Reinforced Slopes Based on Nonlinear Mohr-Coulomb Failure Criterion</title>
      <link>https://trid.trb.org/View/2675949</link>
      <description><![CDATA[Slope stability is crucial to engineering safety, and traditional single safety factor design methods fail to account for parameter variability and nonlinear strength characteristics. This study employs the nonlinear Mohr-Coulomb (M-C) failure criterion to establish safety factor and reliability index constrained optimization models for searching potential slip surfaces. It also proposes a theoretical analysis method for reinforcing slopes with anchor bolts based on reliability theory. The study reveals that potential slip surfaces vary under different failure criteria, with those derived from the nonlinear M-C failure criterion exhibiting deeper slip surfaces. The nonlinearity of strength parameters and their variability significantly impact anchoring force calculations, resulting in notable discrepancies between anchoring forces determined through reliability theory analysis and traditional deterministic analysis. Incorporating the variability and nonlinearity of parameters is of importance for geotechnical engineering computations and design practices. When reinforcing slopes based on reliability theory, it is essential to search for slip surfaces corresponding to the minimum reliability index to ensure slope safety.]]></description>
      <pubDate>Wed, 25 Mar 2026 11:44:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2675949</guid>
    </item>
    <item>
      <title>Numerical investigation of inclined loading and failure envelopes of helical anchors in clay over sand</title>
      <link>https://trid.trb.org/View/2679748</link>
      <description><![CDATA[Helical anchors are increasingly recognised as a promising anchoring solution for tethering offshore floating facilities, owing to their silent installation process and substantial pullout resistance. This paper examines the behaviour of helical anchors subjected to inclined loading in clay over sand deposits. The investigation was carried out through three-dimensional finite element analyses, employing the critical state-compatible bounding surface plasticity model for sand. The results were validated against published data from the literature. A series of parametric analyses were performed to investigate the influence of clay layer thickness, sand layer relative density, mudline loading inclination, and helix-to-pitch diameter ratio on the anchor performance. Compared with the single-layer sand case, the presence of an overlying clay layer significantly reduces the pullout capacity of helical anchors. The maximum vertical and horizontal capacities decrease by 80% and 90%, respectively. A framework is established for estimating the failure envelopes for helical anchors embedded in clay over sand deposits. Unlike existing approaches that mainly focus on vertical loading or homogeneous soil conditions, the proposed framework integrates the combined effects of load inclination and soil stratification. It can provide a practical and straightforward tool for engineering design applications.]]></description>
      <pubDate>Wed, 25 Mar 2026 11:44:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2679748</guid>
    </item>
    <item>
      <title>Experimental and numerical investigation of offset and trajectory during descent of a shell–line–anchor single-point mooring system</title>
      <link>https://trid.trb.org/View/2679740</link>
      <description><![CDATA[The exploration and development of marine resources, as well as advances in marine research, have drawn increasing attention to the deployment dynamics of underwater facilities in complex marine environments. In this study, the descent behavior of a single-point mooring (SPM) system, which consists of a shell structure, mooring lines and gravity anchors, was investigated through a combination of experiments and numerical simulations, and the motion characteristics of the system during the descent process were analyzed in detail. As the current velocity increases, the offset distance also increases significantly. This trend becomes more pronounced at greater depths. During the initial water entry stage, the unsteady motion of the shell reduces the deviation of the anchor, reducing the final offset distance by more than 20%. In addition, the coupling effect of the load ratio and the water depth has a significant impact on the descent trajectory. Under the two water depth conditions of 30 m and 150 m, the favorable parameter range for controlling the distance offset of the structure used in this study is: flow velocity 0-0.1 m/s, load ratio 40%-60%.]]></description>
      <pubDate>Wed, 25 Mar 2026 11:44:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2679740</guid>
    </item>
    <item>
      <title>Cyclic response analysis of suction anchors for floating wind turbine in clays under inclined loading</title>
      <link>https://trid.trb.org/View/2641290</link>
      <description><![CDATA[The mechanical behavior of the suction anchor for floating wind turbines under inclined cyclic loading is an essential consideration in their design. This study investigates the cyclic performance of suction anchors in clay using a modified kinematic hardening model, which considers the cyclic degradation effects of clay and is validated with centrifuge model tests. The effects of loading amplitude, loading frequency and loading sequence on the cumulative deformation of suction anchors and the soil degradation mechanism were systematically investigated. The results show that the cumulative displacement of the foundation will exhibit a noticeable ratcheting pattern when the loading exceeds the critical load. The motion pattern of the foundation gradually changes from an initial oblique upward to a vertical mode as the loading and frequency increase. The loading sequence has a significant effect on the displacements and motion pattern of the foundation, and is related to the maximum historical load applied. The soil degradation zone gradually develops from the foundation end tip to the external side of the foundation skirt as the loading and frequency increase, eventually forming a U-shape. The soil degradation degree can be quantitatively analyzed using a degradation index, which is proportional to the loading amplitude and frequency.]]></description>
      <pubDate>Wed, 11 Mar 2026 14:41:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/2641290</guid>
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