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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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    <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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      <title>Automatic identification and quantitative integrity evaluation of rockmass discontinuities on tunnel face based on 3D laser scanning point cloud data</title>
      <link>https://trid.trb.org/View/2706668</link>
      <description><![CDATA[In the field of discontinuity characterization of tunnel rock masses, developing a reliable, efficient technical method with low manual intervention and highly automated operation is an important research task that urgently needs to be addressed. This paper proposes an effective method based on 3D laser point cloud technology to achieve discontinuity geometric parameter accurate extraction and quantitative characterization in tunnel face rock masses. Firstly, a series of preprocessing techniques, including point cloud downsampling, noise removal, and region segmentation, are adopted to effectively improve data processing efficiency while retaining the key geometric features of the rock mass as completely as possible. Meanwhile, an edge point normal vector update algorithm integrating point cloud classification and regional constraints is proposed, which can not only retain the sharp features of the rock mass structure but also generate high-precision normal vector data. Subsequently, the improved Fuzzy C-Means Clustering (AFCM) algorithm is employed to realize accurate identification and division of the set of discontinuities in the tunnel face point cloud data. Finally, the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm optimized by the k-distance curve method is used to accurately extract individual rock mass discontinuities. Furthermore, key geometric parameters of the discontinuities, such as centroid, spacing, and persistence, are calculated to determine the integrity of the tunnel rock mass in this section. Comparative experimental results based on two sets of measured datasets show that the error between the calculation results of the proposed method and the manual measurement data is less than 5%. In addition, the feasibility and stability of the method are verified through comparative analysis across multiple datasets. In general, this study provides a safe and reliable technical means for technical personnel in rock tunnel engineering to conduct rapid on-site determination of rock mass integrity. The overall calculation time is less than 10 min, which can fully meet the actual operational requirements of tunnel engineering sites.]]></description>
      <pubDate>Fri, 11 Sep 2026 09:14:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2706668</guid>
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    <item>
      <title>New Semiempirical Formula for Evaluating the Equilibrium Scour Depth at Bridge Piers</title>
      <link>https://trid.trb.org/View/2705953</link>
      <description><![CDATA[Estimating the equilibrium scour depth (yse) at bridge piers is essential for both bridge foundation design and flood risk assessment. Traditional methods typically rely on empirical formulas derived from data-fitting procedures, which often result in significant overestimations of the local scour phenomenon. While such conservative predictions may be acceptable for design purposes, they are less suitable for accurate risk evaluation. In this paper, we propose a new formula for predicting yse, grounded in a theoretical framework previously developed by one of the authors. This foundation is enhanced with empirically derived functions, obtained from laboratory data, to account for complex phenomena that remain difficult to capture theoretically, such as sediment nonuniformity. We demonstrate that the resulting semiempirical formula consistently outperforms five of the most widely used local scour methods in the literature. Predictive accuracy is evaluated through four different performance metrics, using more than 600 laboratory data and some selected field data whereby the formula could be confidently applied. The proposed approach provides unbiased estimates and avoids the systematic overestimations that characterize the reference methods, thus making it particularly suitable for risk assessment applications. Furthermore, the potential extension of the model to bridge design is discussed, proposing the introduction of an appropriate safety factor. Finally, we discuss the limitations of the proposed model and outline potential directions for future improvements.]]></description>
      <pubDate>Fri, 11 Sep 2026 09:14:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2705953</guid>
    </item>
    <item>
      <title>Experimental Study on a New Connection Joint between Prestressed High-Strength Concrete Piles and Cap</title>
      <link>https://trid.trb.org/View/2775980</link>
      <description><![CDATA[To address issues such as stress concentration, complex construction, and insufficient deformation resistance faced by the connection joints between prestressed high-strength concrete pipe piles and pile caps under seismic action, this study developed a novel direct reinforcement insertion connection system. Based on the Guohe Bridge project along the S209 Highway in Luyi County, Zhoukou City, China, full-scale specimens with two configurations (Z1: conventional welded connection and Z2: proposed insertion connection) were subjected to unidirectional cyclic loading tests and finite element analysis. Results indicate that, compared with the traditional welded connection, the Z2 insertion connection exhibits a 12% increase in critical load capacity. Under 900 kN lateral loading, displacements measured 39.0 mm (pile) and 42.7 mm (cap), with no load-displacement curve separation observed throughout testing. The reinforcement stress gradient rate in Z2 decreased from 2.68 to 0.32 MPa/mm, with peak tensile stress reduced from 385.0 to 192.3 MPa, and no distinct tension-compression transition zones were identified. Both field tests and numerical simulations confirm the reliability of the new connection system, demonstrating enhanced ductility and coordinated deformation capacity in pile-cap joints.]]></description>
      <pubDate>Fri, 11 Sep 2026 08:43:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2775980</guid>
    </item>
    <item>
      <title>Mesostructure-Informed Balanced Gradation Design of Rubberized Asphalt Concrete for Dam-Face Seepage Control: Skeleton Optimization and Multi-Performance Enhancement</title>
      <link>https://trid.trb.org/View/2767622</link>
      <description><![CDATA[Conventional gradation design for hydraulic asphalt concrete does not explicitly control coarse-aggregate skeleton formation and internal load-transfer paths, limiting the coordinated optimization of multiple performance requirements for dam facings. To address this limitation, a two-stage mesostructure-informed gradation design method integrating Particle Flow Code (PFC) simulation, X-ray computed tomography (CT) characterization, and systematic performance tests was developed. PFC was first used to optimal coarse-to-fine aggregate ratio based on particle packing and force-chain uniformity, followed by CT-based optimization of the internal coarse-aggregate fractions through contact characteristics, spatial uniformity, and compaction orientation. The results show that a 70:30 coarse-to-fine aggregate ratio achieves the densest packing and the most uniform force-chain distribution.Compared with the specification-recommended hydraulic asphalt concrete gradation, the optimized gradation reduces the strength contribution of mortar-mortar contacts by 21.62% and increases that of aggregate-mortar contacts by 65.63%, reconstructing the internal load transfer network from mortar-dominated bearing to aggregate-mortar collaborative bearing. A 3:1 mass ratio (G2 gradation) of 13.2–9.5mm to 9.5–4.75mm aggregates produced the most favorable mesostructure. The G2 gradation increased residual Marshall stability and low-temperature flexural failure strain by 3.75% and 4.56%, respectively, while reducing the 70 °C slope-flow value by 17.84%. These findings confirm that rationally designing mixture gradation based on quantifiable mesostructural parameters can provide a replicable reference for the proportion design of hydraulic asphalt mixtures.]]></description>
      <pubDate>Wed, 09 Sep 2026 09:03:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2767622</guid>
    </item>
    <item>
      <title>Refined Design Methods for Lean-on Bracing</title>
      <link>https://trid.trb.org/View/2767438</link>
      <description><![CDATA[Cross frames are structural elements that are critical for the stability of steel bridges during erection and construction and also play an important role for completed bridges. Historically, the brace locations have been regions of fatigue concerns. In addition, the braces require significant handling and processing during fabrication and represent one of the most expensive components per unit weight on the bridge. Therefore, there are major benefits in terms of economics and structural performance to minimize the number of cross frames. Lean-on bracing concepts that replace full cross frames in certain bracing lines with top and bottom struts that allow a single cross frame to brace several girders is a method of minimizing the number of cross frames on a bridge. Lean-on concepts for bridge applications were developed in the early 2000’s on Texas Department of Transportation (TxDOT) study 0-1772. While the previous study developed design guidelines, recent applications of lean-on bracing on TxDOT bridge designs demonstrated the need for improved efficiency and clarity. The research conducted on this investigation include field monitoring, parametric finite element analyses, and the development of design equations based upon extensive parametric finite element analyses. Results of the research are presented and discussed and refined design methods were developed that provide guidance on effective use of lean-on bracing. The recommendations are demonstrated through design examples.]]></description>
      <pubDate>Wed, 09 Sep 2026 08:52:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/2767438</guid>
    </item>
    <item>
      <title>Drivers Rely on Place Names While Neglecting Exit Numbering in Tunnels: An Empirical Study on Information Prioritization under Cognitive Workload</title>
      <link>https://trid.trb.org/View/2775079</link>
      <description><![CDATA[The spatially constrained environment of tunnels presents significant challenges for guide sign installation, raising questions about the necessity of including exit numbering information alongside place names. This study investigates the impact of simplified tunnel exit signs on drivers’ visual recognition performance through a controlled experimental design. Three sign conditions were compared: simplified signs inside tunnels (place name only), standard exit signs inside tunnels (place name and exit numbering), and conventional signs outside tunnels (open-road baseline condition). Twenty-six licensed drivers participated in three progressive experiments focusing on information retrieval, integration, and consistency judgment. Results demonstrated that simplified signs (place name only) achieved the highest information retrieval efficiency, with significantly reduced reaction times. When place name information was sufficient, exit numbering acted as redundant cues, increasing cognitive load; incongruent number information led to significantly lower accuracy. Notably, many drivers completely ignored exit numbering information, showing significantly greater reliance on place names in tunnel environments. These findings suggest that place name-only simplified signs may improve information processing efficiency in tunnels, and motivate further validation in higher-fidelity driving contexts to inform sign design in spatially limited settings.]]></description>
      <pubDate>Wed, 09 Sep 2026 08:49:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2775079</guid>
    </item>
    <item>
      <title>Field Trials for Cost-Effective Strengthening of SC Load Posted Bridges</title>
      <link>https://trid.trb.org/View/2772575</link>
      <description><![CDATA[The transportation infrastructure in South Carolina includes many bridges that are load posted due to structural considerations (e.g., outdated design loads, members whose capacity is difficult to assess) resulting in substantial costs to the public. The significant number of posted bridges has an adverse effect on travel and commerce in South Carolina. Efficient bridge strengthening methods are described in this report to mitigate these effects. This report focuses on laboratory and field trials of strengthening methods for precast flat slab and channel girder bridges. The goal is provide a means for reducing the number of load-posted bridges through efficient strengthening. Strengthening methods were investigated and laboratory testing was conducted to verify the structural response pre- and post-strengthening. A cost evaluation of the most suitable strengthening methods was performed and selected solutions verified through field implementation and load testing. The outcomes of this research are expected to provide efficient means to minimize the number of loadposted bridges. The work described is part of a larger effort to extend the service life of bridges in South Carolina.]]></description>
      <pubDate>Tue, 08 Sep 2026 11:41:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2772575</guid>
    </item>
    <item>
      <title>Research on the post-earthquake dynamic response of CRTS III slab ballastless track-bridge system in settlement risk area</title>
      <link>https://trid.trb.org/View/2705651</link>
      <description><![CDATA[Current research on high-speed railway track-bridge system primarily focuses on single load conditions of either earthquake or pier settlement, neglecting the coupling correlation between them and severely underestimating the dynamic response of track-bridge system. To address this limitation, a damage evolution model for CRTS III slab ballastless track and an analysis and design method for track residual irregularity characteristics was proposed. First, a simplified track modeling design was adopted to significantly reduce the model degrees of freedom, achieving approximately 40% improvement in computational efficiency compared to traditional finite element models. An adaptive mesh evolution mechanism was introduced to realize local mesh refinement in damaged regions, enhancing the model solution accuracy. The reliability of the damage evolution model was validated through shaking table tests and numerical mapping models. Subsequently, based on this model, the track interlayer damage evolution mechanism and law were revealed, the track interlayer vulnerable regions were identified, and track residual irregularity under the coupling of seismic load and pier settlement were calculated. Through analyzing characteristic parameters such as damage location, damage length, and damage height, the potential causes of abrupt changes in track residual irregularity deformation were explored. Finally, to ensure effective post-earthquake operational safety assessment, wavelet packet transform was employed for time-frequency analysis and feature extraction of residual irregularity signals, and a construction method for characteristic residual irregularity was proposed, enabling irregularity input for post-earthquake train operation simulation. Based on this foundation, an equivalence coefficient of residual irregularity was proposed using the TICrms index, quantifying the aggravation effect of pier settlement on track residual irregularity. The present work is expected to provide theoretical basis and methodological support for post-earthquake operational safety assessment of high-speed railway.]]></description>
      <pubDate>Tue, 08 Sep 2026 11:41:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2705651</guid>
    </item>
    <item>
      <title>Flexural behavior of coarse aggregate-UHPC bridge slabs: A combined phase analysis and layered strength model approach</title>
      <link>https://trid.trb.org/View/2705609</link>
      <description><![CDATA[This study investigates the flexural behavior of coarse aggregate ultra-high-performance concrete (CA-UHPC) bridge slabs, examining size effects and phase distribution from material to structural scales. Vertically cast large-scale specimens were sectioned to evaluate CA and fiber migration, revealing strength variations along the height: compressive, cracking, and flexural strengths increased from top to bottom due to non-uniform phase distribution. Four small-scale slabs extracted from full-scale bridge decks underwent phase analysis and four-point bending tests to study the influences of fiber content, slab dimensions, and shear span ratio on failure modes, load-deflection response, and ductility. Increasing steel fiber content from 1.0% to 2.5% enhanced cracking, yielding, and ultimate loads by 9.7%, 7.1%, and 10.9% (1500-mm span) and 12.1%, 10.5%, and 2.3% (3000-mm span), indicating that larger specimens are less sensitive to fiber heterogeneity at failure. Smaller specimens exhibited stronger flexural-shear interactions and complex interfacial behavior. Analytical models accounting for material heterogeneity showed that neglecting phase distribution overestimates peak load by 10% and midspan deflection by 56%. Future work should include parametric studies quantifying phase distribution effects under varying material compositions.]]></description>
      <pubDate>Tue, 08 Sep 2026 11:41:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2705609</guid>
    </item>
    <item>
      <title>Reassessing eurocode’s lateral vibration criteria for railway bridges</title>
      <link>https://trid.trb.org/View/2705597</link>
      <description><![CDATA[The normative criteria governing the running stability of trains on bridges, especially those limiting lateral vibration, were originally derived from ERRI/D214 research and adopted in EN 1990-Annex A. These standards prevent lateral resonance by requiring each span to have a lateral natural frequency above 1.2 Hz, evaluated under fixed-support conditions. While effective at the time, this limit was based on a narrow dataset of six simply supported bridges and does not capture the diversity of current designs. Resonance was mainly observed in the bridge itself, with limited evidence of its impact on train stability. Recent advances in computational modelling and an expanded dataset of bridge scenarios now allow for more sophisticated simulations of train-track-bridge interaction (TTBI), prompting renewed scrutiny of these guidelines. This study addresses these gaps by combining parametric analyses of 45 bridge scenarios with three train types (TGV, ICE 3, and LAAGRSS) under two track quality conditions. Using in-house TTBI simulation tools, the validity of the established 1.2 Hz lateral frequency threshold is examined. Results confirm resonance effects are confined to bridge displacements and do not propagate to vehicle dynamics, even under enforced frequency coincidence. Running safety indices (Nadal and Unloading) remained well below EN 14363 limits. Track quality emerged as the dominant factor influencing dynamic amplification, overshadowing the role of lateral frequency. These findings indicate that this threshold may be unnecessarily conservative for ensuring running stability and passenger comfort, suggesting the need for updated standards that better reflect contemporary railway bridge dynamics.]]></description>
      <pubDate>Tue, 08 Sep 2026 11:41:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2705597</guid>
    </item>
    <item>
      <title>Computational Analysis of Hydraulic Efficiency of Michigan DOT Covers J and K</title>
      <link>https://trid.trb.org/View/2764016</link>
      <description><![CDATA[Drainage structures are used in urban street and highway systems to capture stormwater runoff. These structures typically consist of catch basins fitted with grates, inlets, or combination grate/inlet configurations that collect runoff and convey it through buried drainage systems. They are strategically placed within curb-and-gutter systems to enhance public safety by efficiently removing water from roadways and thereby reducing the risk of hydroplaning. The performance of drainage structures is commonly evaluated in terms of hydraulic efficiency, defined as the percentage of flow captured by the basin relative to the total flow reaching the structure. Understanding the hydraulic performance of these structures allows designers to properly space inlets, resulting in cost-effective designs that also help ensure the safety of the traveling public. MDOT uses a variety of drainage structures for runoff capture, as documented in Michigan Department of Transportation (MDOT) Drainage Manual [1]. Many of these structures incorporate sinusoidal-type grates that are not addressed in HEC-22 [2]. Because physical modeling of these structures has been limited, further analysis is needed to verify their capture efficiency. Under current MDOT practice, the capture efficiency of these grates is estimated by assuming performance similar to that of a comparably sized reticuline grate described in HEC22. The first phase of this effort, titled Computational Analysis of Hydraulic Efficiency of Michigan DOT Cover C, focused on evaluating the hydraulic performance of MDOT’s Cover C grate. Cover C was selected as the initial test candidate because its sinusoidal pattern is representative of other MDOT grates, while it is typically used in high-volume, higher-speed applications. A similar version, Cover CX, is used on interstate highways but does not include transverse bars for bicycle safety. The current second phase of the study expands this work to evaluate MDOT’s Covers J and K. These grates were selected for additional analysis to further assess the hydraulic performance of MDOT drainage structures that are not directly represented by grate configurations in HEC-22. The results of this phase will build on the findings from the Cover C analysis and support improved understanding of the capture efficiency of MDOT’s standard drainage grates. This report is intended to serve as a companion document to the earlier study, Computational Analysis of Hydraulic Efficiency of Michigan DOT Cover C [3]. The present work applies the same overall CFD-based evaluation approach to MDOT Covers J and K and compares the resulting performance trends with those previously identified for Cover C. In particular, both studies assess on-grade interception efficiency, sag-location hydraulic capacity, and the effects of partial obstruction relative to HEC-22-based design estimates.]]></description>
      <pubDate>Tue, 08 Sep 2026 10:49:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2764016</guid>
    </item>
    <item>
      <title>Computational Modeling of Water Infiltration From Ditches Into Roadway Embankments</title>
      <link>https://trid.trb.org/View/2764014</link>
      <description><![CDATA[Ditches are built along roadways to convey the stormwater runoff. They collect the runoff from the pavement and adjacent drainage areas. Water can move freely in a ditch away from the road surface, thus making it safer for the vehicular traffic. South Carolina DOT expressed interest in studying infiltration of water from ditches into roadway embankments. As part of the current design criteria, it is recommended that the road subgrades be 1.0 foot above the design event water surface elevation in the ditch. The distance between the water surface and bottom of the subbase is referred to as “freeboard”. The purpose of this requirement is to lower the risk of pavement damage by moving the flow away from the pavement, containing the captured flow, and conveying flow received from adjacent properties to outfalls. With changes in roadway design standards, larger shoulders and flatter cross-slopes have moved ditches further away from the pavement and the subbase. These changes could allow for a lower freeboard standard without reducing safety margins due to the increased lateral distance from the subbase to the ditch. The objective of this study is to evaluate whether the current SCDOT criterion requiring the roadway subgrade to be 1 ft above the design-event ditch water surface can be relaxed under selected geometric and soil conditions, particularly where larger shoulder widths and flatter side slopes increase horizontal separation between ditch water and pavement structure.]]></description>
      <pubDate>Tue, 08 Sep 2026 10:49:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2764014</guid>
    </item>
    <item>
      <title>Evaluation of Steel Bridge Girders Damaged by Over-height Vehicle Strikes Using Terrestrial Laser Scanning and Machine Learning</title>
      <link>https://trid.trb.org/View/2736755</link>
      <description><![CDATA[Bridge strikes caused by over-height vehicles frequently damage steel girders and can reduce their load-carrying capacity, requiring rapid and reliable evaluation to ensure structural safety. Current evaluation practices rely on manual measurements that often require traffic disruptions and simplified assessment approaches that do not fully capture the effects of damage. In addition, finite element simulations are time-consuming and computationally intensive to develop for practical rapid evaluation. This study developed an integrated, data-driven framework for the inspection and assessment of damaged steel bridge girders. A semiautomated procedure was developed to process laser-scan point cloud data and extract displacement profiles along the girder span. Machine learning models were trained and validated using a dataset generated from finite element simulations informed by field measurements of actual bridge strike incidents to predict the residual capacity of damaged girders. Explainable artificial intelligence techniques were incorporated to interpret model predictions and identify key parameters influencing structural performance. Results demonstrated the framework's capabilities in effectively capturing girder displacements, and for accurately and efficiently estimating the residual capacity, to support post-strike bridge evaluation. Measured girder deformations obtained from laser scanning can be used as inputs to the machine learning models for quantifying a girder's capacity. The predicted capacity can then be incorporated into bridge rating software to compute rating factors, enabling rapid decisions on traffic restrictions and load posting. Additionally, the interpretability results can guide engineers in identifying critical design parameters and prioritizing repair actions.]]></description>
      <pubDate>Tue, 08 Sep 2026 10:49:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2736755</guid>
    </item>
    <item>
      <title>Investigate Live Load Distribution and Stability of Prestressed Concrete Girders During Construction</title>
      <link>https://trid.trb.org/View/2767343</link>
      <description><![CDATA[Prestressed concrete girders are widely used in bridge applications in the state of Texas. While the girders have traditionally been utilized for simply-supported bridges, continuous-girder applications have been used recently by employing spliced-concrete girders that allow significant increases in the spans. However, the larger spans introduce increased girder slenderness that can introduce potential stability limit states that historically have not been an issue with simple-span systems. In addition, the larger spans of the girders can also have an impact the live load distribution of the girders. This report documents a comprehensive investigation on the stability behavior of prestressed concrete girder systems throughout the erection and construction process and also considers the live load distribution of the in-service bridges. Full scale laboratory experiments were conducted to measure the flexural and torsional behavior of the girders in both the uncracked and cracked state. The results from the laboratory tests were utilized to validate three-dimension finite element models that were used to consider girder stability throughout the erection and construction stages of the deck. Because cracks that might occur during transportation and erection are often closed from the prestressing, cracked section properties were utilized to assess the girder stability. The impact of diaphragms on the stability girder behavior and also live load distribution were studied. Recommendations are provided for diaphragm bracing, stability evaluation, and live load distribution in the girders.]]></description>
      <pubDate>Tue, 08 Sep 2026 10:46:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2767343</guid>
    </item>
    <item>
      <title>The Use of Foamed Glass Aggregate (FGA) as a Lightweight Fill Above Culverts</title>
      <link>https://trid.trb.org/View/2767315</link>
      <description><![CDATA[Transportation infrastructure—including buried utilities, drainage systems, and culverts—is frequently subjected to significant external stresses arising from existing conditions and new construction, especially in urban environments where deformation and failures can lead to significant operational and safety consequences. Lightweight fills offer a viable strategy to mitigate these stresses by reducing imposed loads. This study investigates the use of lightweight fills, specifically Foamed Glass Aggregate (FGA), as a sustainable solution to support California Senate Bill 1 (SB1) efforts to repair and maintain culverts, as well as for new construction applications. A numerical investigation was conducted to evaluate the performance of culverts backfilled with FGA compared to conventional fills. Models were developed for reinforced concrete box culverts and corrugated steel pipe culverts, and parametric analyses were performed across a range of configurations. Results indicate that FGA significantly reduces soil stresses, structural demand, deformation, and settlement compared to conventional fills. This study also developed design and construction guidance and proposed updates to California Department of Transportation (Caltrans) manuals to facilitate implementation in practice. The findings demonstrate that FGA is an effective, sustainable alternative for improving culvert performance in California and beyond, helping agencies better address aging infrastructure and increasing construction demands.]]></description>
      <pubDate>Tue, 08 Sep 2026 10:46:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2767315</guid>
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