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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Evaluating the Effectiveness of Asphalt Layer in Improving Railway Track Stiffness through 3D Numerical Simulations</title>
      <link>https://trid.trb.org/View/2344320</link>
      <description><![CDATA[In the last three decades, railways have gradually increased the weight and speed of trains to improve their capacity, profitability, and efficiency. This approach has provided overall benefits; however, it has also led to increased track and structure maintenance costs. The subgrades of railway tracks now experience higher stress, resulting in significant deformation and, in extreme cases, embankment shear failure. Therefore, ground improvement methods should be introduced to reduce stress and deformation in tracks and ensure that the subgrade can safely withstand the increased axle load. One effective ground improvement method is the use of an asphalt layer, which has been successfully applied in many countries. The thickness of the asphalt layer varies from 10 to 20 cm, depending on the regulations of each country. In this study, the finite element program ABAQUS is utilized to model a three-dimensional railway track and investigate the effectiveness of using an asphalt layer to improve the track modulus. The model is calibrated based on experimental observations and used to determine the effects of different combinations of asphalt and granular layers on the stress and displacement of the subgrade under static load. Considering the importance of track modulus in long-term track behavior, the Winkler theory is employed to estimate the track modulus. The results suggest that increasing the thickness of the asphalt layer from 10 to 18 cm significantly reduces the stress and displacement of the subgrade, resulting in uniform displacement.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344320</guid>
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    <item>
      <title>Deformation of Unbound Granular Materials in Three-Dimensional Stress State</title>
      <link>https://trid.trb.org/View/2344323</link>
      <description><![CDATA[Unbound granular materials (UGMs) are extensively used in pavements mostly as subgrade and subbase materials. Excessive permanent settlement or rutting is the main damage mechanism encountered in UGMs. Rutting is a result of accumulated gradual plastic strain in the subbase and subgrade layers subjected to repetitive traffic loadings. Axisymmetric triaxial apparatus or repeated lateral triaxial (RLT) devices are commonly used to explore the rutting of UGMs. However, these devices are not able to capture the actual stress state generated in traffic. A soil element in pavement layers is in a three-dimensional (3D) stress state and includes all three components of cyclic principal stresses. A typical pavement also can be considered geometrically as a plane strain structure. Accordingly, aim of this study is to carry out experiments to determine the long-term deformation of a silty sand in plane strain and in a 3D stress state using a multistage true triaxial apparatus (TTA). It is found that the permanent deformation of UGMs under plane strain and 3D anisotropic stress state differs significantly from that under axisymmetric stress. An increase in the intermediate principal stress was observed to decrease the total and permanent deformation. An increase in cyclic stress level was also found to increase the rutting in UGMs. The deformation of soil under the plane strain state was found to be less than that in the axisymmetric stress state but falls into an intermediate range when compared to tests involving 3D cyclic loading.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344323</guid>
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    <item>
      <title>Study on Hydraulic Conductivity of Cement-Treated Pavement Base Course Made of Recycled Plastic and Concrete Aggregates</title>
      <link>https://trid.trb.org/View/2344306</link>
      <description><![CDATA[The primary objective of this study is to analyze the hydraulic characteristics of cement-treated pavement base course, which is fabricated of recycled plastics and recycled crushed concrete aggregates (RCCA). To fulfill this objective, representative cylindrical pavement base course samples, stabilized by certain dosages of cement, have been prepared incorporating both shredded plastics and recycled aggregates, and prepared samples were then subject to constant head permeability test following the standard of ASTM D2434. In this study, three different types of plastics, that is, polyethylene terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP), have been used in three varied proportions (0%, 3%, and 5%), and four different cement dosages (4%, 6%, 8%, and 10%) have been considered for stabilization purposes. This study comes to opine that percentage of both plastic and cement dosage in respective samples significantly influence hydraulic conductivity numbers of pavement base course. In short, this study did reveal that hydraulic conductivity values tend to lessen significantly with increasing cement dosage, and on the contrary, hydraulic conductivity numbers were observed to increase exponentially with the increase of plastic percentages.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344306</guid>
    </item>
    <item>
      <title>Environmental and Financial Benefits of Foamed Bitumen Stabilisation as a Sustainable and Resilient Airport Pavement Rehabilitation Technology</title>
      <link>https://trid.trb.org/View/2344303</link>
      <description><![CDATA[Foamed bitumen stabilisation is a technology that allows existing granular pavement structures to be strengthened and made moisture resistant, while avoiding the replacement of the existing granular material. It is believed that foamed bitumen stabilisation provides more resilient and sustainable airport pavements, but that has not been quantified. This research objectively compared foamed bitumen stabilisation of an existing pavement to other common airport pavement rehabilitation options, within the context of a case study on the design of a regional Australian airport. The stabilisation of the existing marginal gravel base course with foamed bitumen and a new asphalt surface was the most financially economical solution, the second most resilient solution, and the most environmentally sustainable solution. It was concluded that the foamed bitumen stabilisation and asphalt surface pavement design was the most sustainable and resilient pavement option. It is recommended that in the future, this comparison be extended to include a whole of life assessment of the different pavement design options.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344303</guid>
    </item>
    <item>
      <title>Use of Artificial Neural Network to Determine the Pavement Layer Properties Based on Automated Plate Load Test</title>
      <link>https://trid.trb.org/View/2344301</link>
      <description><![CDATA[Nowadays, automated plate load tests (APLTs) are used to evaluate the performance in terms of deflection data obtained from different magnitudes of loading. Several back-calculation methods are currently available to determine the pavement layer modulus based on the deflection bowl data obtained from the regular falling weight deflectometer (FWD). However, the configuration and number of sensors used for the APLT slightly differ from the routine FWD test. To determine the pavement layer properties from the APLT, there is a need to develop a back-calculation approach. In this study, a series of pavement analyses have been performed to simulate the loading condition of APLT with a multi-layered elastic analyses approach. The elastic deformations obtained from the pavement analyses were correlated with the pavement layer thickness and moduli based on the artificial neural network (ANN) approach. The feedforward approach of ANN was selected for this study. The developed ANN model was further used to predict the base layer modulus of different pavement sections.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344301</guid>
    </item>
    <item>
      <title>Resilient Modulus Prediction from Regression and Machine Learning Algorithms</title>
      <link>https://trid.trb.org/View/2344282</link>
      <description><![CDATA[Laboratory determination of resilient modulus (MR) is time consuming and requires expensive equipment and extensive expertise. This has led researchers to develop empirical correlations for MR based on stress state, index, and engineering properties of the soil. In the current study, subgrade soils were collected from 10 road construction projects covering a range of soils (A-1 to A-7-6; untreated to chemically treated) found across Indiana. These soils were tested in the laboratory, and attempts were made to establish correlations between select soil properties such as Atterberg limits, percentage of fines, compaction parameters, and MR. A review of existing models as well as model verification was conducted for Indiana soils. For untreated specimens, the results showed a weak dependence on deviatoric stress and confining stress, while for treated specimens, it was observed that the model parameters increased with treatment, consistent with an increase in MR. It was also found that machine learning tools, specifically the gradient boost regressor model, provide better predictions than traditional regression analyses.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344282</guid>
    </item>
    <item>
      <title>Initial Evaluation and Structural Contribution from Full Depth Reclamation Technique for Rehabilitation of Airfield Asphalt Pavements</title>
      <link>https://trid.trb.org/View/2344285</link>
      <description><![CDATA[This paper discusses the preliminary findings from a full-scale evaluation of full depth reclamation (FDR) technique and reports the contribution of FDR layers to the overall pavement structural capacity under aircraft loading conditions. A full-scale pavement section, previously trafficked with a heavy tactical aircraft, was selected as a candidate pavement to evaluate the effectiveness of the FDR technique. The existing asphalt pavement exhibited significant structural deterioration with rut depths greater than 59 mm. Nondestructive and semi-intrusive tests were performed to assess the pavement structural condition. The Pavement-Transportation Computer Assisted Structural Engineering (PCASE) software was used to investigate the contribution of the FDR base layers to the overall pavement performance. From this study, the FDR technique improved the structural capacity of a structurally failed asphalt pavement based on falling weight deflectometer data and showed promise as a deployable rehabilitation approach for airfield pavements encountered during contingency aircraft operations in remote locations.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344285</guid>
    </item>
    <item>
      <title>Experimental Design for Complex Resistivity Measurements of Unsaturated Soils: Application for Fouled Ballast</title>
      <link>https://trid.trb.org/View/2344279</link>
      <description><![CDATA[Degradation of railroad ballast via ballast fouling is a persistent issue for the track structure. Ballast fouling (i.e., intrusion of materials passing the 3/8 sieve) compromises the integrity of the track system by reducing the shear strength and impeding drainage. This research seeks to understand the unsaturated characteristics of ballast fouling materials, including the electromagnetic properties, to further describe ballast aggregate and fouling particle interactions. There has been limited research in geotechnical engineering with complex electrical resistivity, yet it is used in geophysics to study bulk soil properties, particle to particle properties, biofilm formation, and biogeochemical processes. Although the use of this method has had a resurgence in geophysics, most studies are on fully saturated specimens. The objectives of this study were to establish the experimental methods for unsaturated complex resistivity measurements and to highlight the advantages of this measurement with ballast fouling materials. Measurements were conducted in a non-conducting acrylic box from 0.07 to 20 kHz with Cu-CuSO₄ potential electrodes and three current electrode materials: copper, copper foam, and stainless steel. Results indicate that copper foam electrodes were the most optimal for unsaturated complex resistivity measurements. Also, ballast fouling materials were differentiable when fully saturated using complex resistivity, and a different response for each material can be measured at lower levels of saturation. All results were validated using the generalized Cole-Cole model and mean time constants. These findings are significant because the influence of saturation can make discerning different geomaterials in single frequency electrical resistivity measurements impossible. Thus, complex electrical resistivity measurements provide more information about geomaterials than traditional single frequency electrical resistivity measurements. The long-term goal of this research is to establish the unsaturated electromagnetic, suction, and strength characteristics of fouled ballast as a function of the fouling material and moisture content. This will improve the fundamental understanding of ballast degradation characteristics and non-destructive identification of fouled ballast in the field, and ultimately improve the performance and safety of the track structure.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344279</guid>
    </item>
    <item>
      <title>Investigations on Fully Softened Strength of Lime-Treated Slopes Built with Expansive Soils under Future Extreme Precipitation</title>
      <link>https://trid.trb.org/View/2344259</link>
      <description><![CDATA[Highway slopes built with expansive soils are often prone to surficial slope failures due to volumetric fluctuations from cyclic ingress and egress of moisture arising from repeated wet-dry weathering cycles. This periodic shrink-swell phenomenon may result in the formation of desiccation cracks, which result in the transition of strength from peak to fully softened and subsequently result in surficial slope failures. Calcium-based stabilizers such as lime are often used to negate the effects of high-plastic clay by enhancing strength and subsequently reducing volumetric strains. However, cyclic wetting and drying can often impact the long-term serviceability of such treated slopes. A research study was conducted to understand the efficacy of different lime dosages against surficial slope failures. Laboratory studies were performed on untreated, 5%, and 8% lime-treated soils at two different curing periods to estimate the changes in peak and fully softened shear strengths. Rainfall-induced slope stability analyses were performed on a hypothetical slope considering the effects of future precipitation in Texas and determining the stability of lime-treated surficial slope. Preliminary studies indicate that lime treatment improves the fully softened strength, and a unique relation exists between the treated soil plasticity and the secant friction angle values. Stability analyses indicated that the lime-treated slopes are less prone to degradation from repeated wet-dry cycles due to the formation of a hydrophobic and resilient soil matrix. Overall, the study provides a comprehensive insight into chemically stabilized surficial slope failures and the effects of environmental changes on the serviceability of this transportation infrastructure.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344259</guid>
    </item>
    <item>
      <title>Effects of Jointed Plain Concrete Pavement’s Design Inputs on Performance Indicators</title>
      <link>https://trid.trb.org/View/2344275</link>
      <description><![CDATA[The most used rigid pavement throughout the United States is jointed plain concrete pavement (JPCP), providing a service life of 30 years or more. JPCP is proven to be a cost-effective pavement system, providing long service life and other sustainability benefits. The structure of JPCP systems and other critical factors, such as material properties, traffic, and climate, impact the performance and serviceability of the JPCP. The analysis of impacts of all these design variables is necessary to understand the most critical factors affecting JPCP lifetime performance. The state-of-the-art pavement ME design (PMED) software evaluates the pavements’ performance through the international roughness index (IRI), joint faulting, and transverse cracking. This study focuses on performing a sensitivity analysis of the design inputs used in PMED software on the predicted performance of JPCP systems. Simulations were performed using the PMED software version 2.6.2.1 for various JPCP design inputs that include pavement structure, mechanical and thermal properties of paving concrete, climate, and traffic. Variables assessed are coefficient of thermal expansion (CTE), Portland cement concrete (PCC) slab thickness, slab width, slab length, friction loss, PCC shortwave absorptivity, PCC thermal conductivity, dowel diameter, PCC heat capacity, climate, and traffic. The data produced from the PMED software simulations is analyzed based on the JPCP performance indicators. Results on the IRI indicator analysis show CTE, PCC thickness, and climate to have the most impact. CTE, climate, and slab width hold the most impact on the joint faulting indicator. The transverse cracking indicator results present CTE, slab length, and friction loss exhibiting the most impact. It is evident from the sensitivity results that CTE of paving concrete holds the most influence among all three JPCP performance indicators.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344275</guid>
    </item>
    <item>
      <title>Accelerated Bridge Construction in Challenging Geology: The Geotechnical Aspects of the Veranda Street Bridge Replacement</title>
      <link>https://trid.trb.org/View/2344257</link>
      <description><![CDATA[This case history details the unique geotechnical solutions utilized to accommodate the foundation challenges associated with the accelerated replacement of the I-295 bridge over Veranda Street in Portland, Maine. The existing three-span structure was replaced with a new shorter single-span bridge over the course of a continuous weekend outage utilizing accelerated bridge construction (ABC) techniques. This strategy required significant substructure and embankment construction beneath the active existing bridge prior to replacement to minimize activities scheduled for the weekend outage. The existing bridge was supported on battered H-pile foundations driven through up to 60 ft (18 m) of soft Presumpscot Formation marine clay. Settlement using normal-weight embankment material was estimated to exceed 6 in. (152 mm) but needed to be mitigated to avoid inducing bending in existing battered piles, which could otherwise result in deflection or damage to the piles supporting the active bridge above. Low-clearance operations and a deep and sloping bedrock bearing layer further complicated construction. A combination of deep foundation and lightweight embankment options was selected to address the project challenges and prepare the site for the ABC weekend closure. The construction phase quality assurance testing program identified the potential for variability in expanded polystyrene backfill (a.k.a. EPS geofoam) and fortified the need for a rigorous construction-phased testing program on all EPS projects beyond vendor quality control testing and third-party verification. This case history shares considerations and measures taken to successfully construct embankments and substructure beneath active bridge spans. Additionally, the case history examines the EPS testing program implemented during construction to address variability in the properties of delivered EPS fill.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344257</guid>
    </item>
    <item>
      <title>Correlation between Resilient Modulus, Permanent Strain, and Damping Coefficients for Undisturbed Subgrade Soils</title>
      <link>https://trid.trb.org/View/2344246</link>
      <description><![CDATA[To properly model the subgrade soil responses under dynamic loads, permanent deformation and damping characteristics must be studied in addition to the subgrade resilient modulus. Soils having relatively high resilient modulus may or may not have small permanent strains (εp) and low damping characteristics (ξ). Therefore, in addition to the resilient modulus (MR), permanent deformation and damping characteristics also need to be studied for undisturbed subgrade soils to replicate field conditions under cyclic loading properly. This study correlates permanent strain and damping information with resilient modulus testing for undisturbed subgrade soils. For this study, 76 Shelby tube samples of subgrade soils were collected from existing pavements in three different regions: SC-93 in Pickens County (Upstate Area), US-521 in Georgetown County (Coastal Plain), and US-321 in Orangeburg County (Coastal Plain, near the fall line). Statistical models were developed to correlate resilient modulus (k1, k2, k3), permanent strain (α1, α2, α3, α4), and damping model parameters (β1, β2, β3) with soil index properties for undisturbed soils. Models were also developed to correlate εp and ξ with subgrade soils MR.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344246</guid>
    </item>
    <item>
      <title>An Investigation of Sources of Asymmetric Thermal Expansion Behavior in Semi-Integral Bridges</title>
      <link>https://trid.trb.org/View/2344255</link>
      <description><![CDATA[The typically poor long-term performance of deck expansion joints and the high cost of maintenance of these bridge components have led to an increased utilization of jointless bridge systems such as integral and semi-integral bridges. However, the elimination of expansion joints leads to some adverse secondary effects due to the cyclic interaction of the bridge with the abutments. This soil-structure interaction can cause gradual settlement of the backfill, backfill earth pressure increase, and lateral loading of the foundations. In addition to these issues, it has been observed that integral and semi-integral bridges do not necessarily experience the symmetrical thermal expansion and contraction that is typically assumed in design, even if the structure appears symmetrical in design. As a result, jointless bridges may expand more toward one abutment than the other in response to daily and seasonal changes in temperature. In this paper, some of the potential causes of the asymmetrical expansion of integral and semi-integral bridges are identified and discussed through analysis of some of the past field monitoring data as well as the available data published in literature. The identified causes include minor differences in foundation soil stiffness, depth of the foundation, environmental forces, and more.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344255</guid>
    </item>
    <item>
      <title>Simulation of Weather-Driven Deterioration of Clay Embankments</title>
      <link>https://trid.trb.org/View/2344237</link>
      <description><![CDATA[Clay embankments used for road, rail, and flood defense infrastructure experience several weather-driven deterioration processes that lead to a progressive degradation in their hydromechanical performance. This paper presents a numerical modeling approach that accounts for the development of desiccation cracking in clay embankments. Specifically, a bimodal soil-water retentivity model was adopted to capture the long-term hydraulic behavior of clay embankments prone to weather-driven desiccation cracking. A numerical model was developed for a heavily instrumented and monitored full-scale research embankment with long-term field data. The model was able to capture the variation of near-surface soil moisture and matric suction over a monitored period of nine years in response to weather cycles. The developed and validated numerical modeling approach enables forecasting of the long-term performance of clay embankments under a range of future climate scenarios.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344237</guid>
    </item>
    <item>
      <title>Investigation of Geotechnical Impacts in Response to 2022 Hurricane Ian</title>
      <link>https://trid.trb.org/View/2344208</link>
      <description><![CDATA[On September 28, 2022, Hurricane Ian made landfall near the city of Fort Myers, Florida, as a category 4 hurricane, which brought sustained winds of 150 mph, observed storm surge heights of up to 12 ft, and rainfall totals up to 20 in. Coastal communities around Fort Myers were the most heavily impacted, including 148 deaths and an estimated 113 billion dollars’ worth of damage. The inflation-adjusted economic impact is projected to make Hurricane Ian the third most costly hurricane in United States history. Three weeks after the storm impact, from October 18 to 22, a five-member NSF-sponsored Geotechnical Extreme Events Reconnaissance (GEER) Association team was deployed to Fort Myers and the surrounding areas to study the geotechnical impacts resulting from Hurricane Ian. Primary technologies used to study impacts included a terrestrial light detection and ranging (LiDAR) system, unmanned aerial systems (UAS), soil sampling equipment, and mobile phone cameras. Additionally, two team members returned during November 29–30 to study the recovery progress and implement a multispectral imaging workflow to further investigate impacted structures. Primary surveyed locations include the city of Fort Myers, Fort Myers Beach, Pine Island, Port Charlotte, and the Peace and Caloosahatchee Rivers. Primary observations include a rail bridge failure, sea wall failures, varying degrees of foundation performance, and high degrees of scour and erosion along coastal sites. This GEER deployment allowed for rapid and high-fidelity data collection on impacts related to geotechnical assets following a major hurricane. The dataset and subsequent GEER report from this deployment will allow for improved study of hydraulic and erosional processes related to soil-structure interactions, which will in time improve flood and storm design practices in coastal communities.]]></description>
      <pubDate>Wed, 22 May 2024 09:10:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2344208</guid>
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