<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <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>
    </image>
    <item>
      <title>Roadway Runoff Impacts to Trout Streams Studies for MS4 Permit</title>
      <link>https://trid.trb.org/View/2681204</link>
      <description><![CDATA[This study evaluated roadway runoff impacts on trout stream temperature and dissolved oxygen to support Georgia Department of Transportation (GDOT) Municipal Separate Storm Sewer System (MS4) Permit compliance with Georgia Rule 391-3-6-.03(6) for trout streams. Using YSI ® ProDSS, HOBO ® MX-801 Dataloggers, and low-cost ESP32-based sensors, the Georgia Southern University (GSU) research team collected summer season data over two (2) consecutive years at 2-3 representative GDOT outfalls at each of the three (3) secondary trout streams. Results show that summer rainfall events with precipitation ≥ 0.5 inches produced short-term temperature increases at Sites 1 and 2, with Site 1 (Chattahoochee River) exhibiting brief exceedances above the 2 °F limit for secondary trout waters. Site 2 (Powder Springs Creek) displayed smaller rises that rarely approached the threshold, while Site 3 (Two-Run Creek) showed no measurable temperature increase under any rainfall conditions. DO reductions tracked temperature inversely but remained within regulatory limits after artifact screening. All impacts were event-specific and recovered within hours. The project establishes a scalable monitoring framework that can be applicable nationwide and provides site-specific BMP guidance to strengthen GDOT’s MS4 Permit compliance and protect sensitive secondary trout streams.]]></description>
      <pubDate>Thu, 19 Mar 2026 08:56:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2681204</guid>
    </item>
    <item>
      <title>Air Core Vortexing in Liquid Draining Vessels: Impact of Drain Port Vanes</title>
      <link>https://trid.trb.org/View/2594162</link>
      <description><![CDATA[AbstractVortex formation in liquid propulsion tanks can obstruct propellant flow, reduce discharge efficiency, and cause cavitation in feed pumps, posing a risk to spacecraft and rocket performance. To mitigate these ill effects, intrusive vortex suppression strategies, such as vanes, have been explored. This study experimentally investigates the effect of vanes positioned inside a circular drain port on air-core vortexing in precritical and postcritical height regimes. A newly introduced discharge number quantifies vortex suppression. Experiments are conducted using a liquid draining setup, where vanes of varying configurations are tested under different initial rotation conditions. The study measures the critical height, emptying time, and critical time, while the air-core blockage percentage and static pressure near the drain port are determined analytically to analyze vortex behavior. Results indicate that vanes enhance draining efficiency in the postcritical regime by weakening the air-core vortex but hinder discharge in the precritical regime by increasing frictional resistance. These findings have practical applications in optimizing liquid propulsion systems, ensuring uninterrupted propellant flow, reducing vortex-induced cavitation risks, and improving spacecraft engine performance. Building on these findings, the study suggests implementing a selective electro-mechanical system that deploys vanes only after critical height formation, thereby optimizing fuel management in aerospace propulsion systems.]]></description>
      <pubDate>Wed, 11 Mar 2026 14:44:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2594162</guid>
    </item>
    <item>
      <title>Development of a Novel Trash Capture Device for Highway Environments</title>
      <link>https://trid.trb.org/View/2606252</link>
      <description><![CDATA[Traditional trash capture devices that can be installed in upstream locations such as storm drains or curb inlets are of limited use in highway environments due to potential flooding, hydroplaning, safety, and maintenance-personnel exposure issues. There is a need for a trash capture system that can be retrofitted easily into existing highway drainage infrastructure or included in newer projects. To address this issue proactively, the California Department of Transportation (Caltrans) Division of Environmental Analysis (DEA) initiated a trash capture device development and testing project in early 2020. The DEA Stormwater staff developed the initial idea for a capture housing device. Computational fluid dynamics modeling was used first to assess the feasibility and performance. Next, the hydraulic capacity, trash capture characteristics, operation, and ease of maintenance were tested using a full-scale physical model. After successful testing, standard plans and design guidance were developed. The full-scale model physical test demonstrated the following: (1) the device can pass the 1-year, 1-h storm intensity specified in the regulations without overflowing or causing roadway flooding; (2) the device can pass the 25-year 5-min-duration return period storm drain system design storm event without causing roadway flooding; (3) the device will trap trash sizes of 5 mm or larger for the 1 year, 1-h storm intensity specified in the regulations; and (4) the device has the storage capacity for the quantity of trash generated from a typical 0.405 ha (1-acre) highway drainage area.]]></description>
      <pubDate>Fri, 09 Jan 2026 16:25:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2606252</guid>
    </item>
    <item>
      <title>Field Evaluation of Drainable Bases in Oklahoma</title>
      <link>https://trid.trb.org/View/2633697</link>
      <description><![CDATA[The Oklahoma Department of Transportation (ODOT) Research and Development Division (R&D) installed field data acquisition systems in 1992 on five test pavement sections with a view to evaluate the performance of the drainable base and edge drain systems in Oklahoma. Rainfall, outflow and other data have been collected continuously since that time. The University of Oklahoma (OU), in association with ODOT, analyzed the field data, developed appropriate computer programs (written in SAS 6.08 language) to analyze the data, developed a simple, quick and efficient field test scheme to evaluate the drainage efficiency of the existing pavement sections, and conducted a number of field tests for this purpose. This report presents the results of these studies. The useful data, containing rainfall values and the corresponding outflow values reflecting the drainage characteristics of the pavement drainage system were identified and grouped into a number of "events." The events were studied to establish any relationship between outflow and rainfall magnitudes, flow rates, time required to initiate flow in different types of pavements, and time required for drainage. This information was combined to determine the drainage efficiency of the corresponding drainable base and edge drain system. Finally, the time for 50% drainage was computed and compared with the AASHTO guidelines to determine the drainage quality of the pavements under investigation. This report presents the steps involved in grouping, analyzing and interpreting the field data, and explains the findings with appropriate textual and graphical illustrations. A field test procedure was developed to facilitate a quick examination of the quality of a pavement drainage system. The procedure for this field test, results of the field tests performed, and a comparison with regular rainfall and outflow data are also presented in this report.]]></description>
      <pubDate>Sat, 03 Jan 2026 10:54:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2633697</guid>
    </item>
    <item>
      <title>Modeling of PVD-improved embankment underneath soft sensitive clays considering soil disturbance</title>
      <link>https://trid.trb.org/View/2587253</link>
      <description><![CDATA[Plastic Vertical Drains (PVDs) are commonly used in soft soil foundation treatment as a means to facilitate drainage and accelerate the consolidation process, significantly improving foundation strength and stability. However, existing studies mainly focus on the drainage effect and consolidation efficiency of PVD, with limited attention given to the impact of PVD installation on the structure and time-dependent properties of soft soil. This paper investigates the influence of soil disturbance induced by the installation of PVD in soft sensitive clays. Three typical matching techniques for modeling the PVD-improvement under the plane strain condition are adopted for comparison. An advanced elasto-viscoplastic model accounting for anisotropy and destructuration of natural soft clay is employed. A well-documented PVD-improved test embankment is adopted for simulations by the elasto-viscoplastic model combined with three mapping techniques respectively. To quantify the degree of soil disturbance, a new variable, δ, is introduced as an additional input parameter to the model, enabling the consideration of soil disturbance-induced strength degradation and hydraulic conductivity modification. The predictions of settlement, vertical displacement, horizontal displacement and excess water pore pressure, using different values of δ, are compared against field measurements. An appropriate value of δ is determined for each mapping technique based on the quality of the fit to the measurements. The results demonstrate that soil disturbance has a significant impact on settlement. Finally, the performance of the three mapping techniques is evaluated in terms of predictive accuracy and practical applicability.]]></description>
      <pubDate>Fri, 19 Sep 2025 10:16:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2587253</guid>
    </item>
    <item>
      <title>Drains that Provide Highly Efficient Drainage of the Subgrade and Increase of the Subgrade</title>
      <link>https://trid.trb.org/View/2407908</link>
      <description><![CDATA[Purpose. Finding an effective solution for draining the subgrade in poorly permeable soils with a non-swamp drainage system while increasing its load-bearing capacity. Methodology. Low permeability soils have a very low drainage coefficient and consequently long drainage times when the drainage spacing is large. A methodology for the hydraulic calculation of non-swamp drains of different cross-sectional shapes has been developed. This provides a different height of water level reduction in the subgrade with approximately the same increase in its load-bearing capacity. Results. The calculations carried out make it possible to establish the most favourable shape of the live cross-section with the same hydrological load on the non-swamp drain in terms of the amount of water level reduction in the subgrade. Practical relevance. The installation of non-swamp drains in the subgrade along with efficient drainage ensures an increase in the load-bearing capacity. The construction of a sub-cavity drainage system is not necessary allowing to reduce costs both during the construction of the railway bed and during its operation.]]></description>
      <pubDate>Tue, 29 Jul 2025 13:56:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407908</guid>
    </item>
    <item>
      <title>Soft Soil Consolidation Using Prefabricated Vertical Drains: Case Study of “Radès la Goulette” Bridge Project</title>
      <link>https://trid.trb.org/View/2573148</link>
      <description><![CDATA[This study examined the consolidation settlement of Tunisian soft soil at the Radès la Goulette bridge project using prefabricated vertical drains (PVD) installed to a depth of 10 m, combined with incremental preloading. Extensive field instrumentation monitored settlement throughout construction. Laboratory model tests replicated field conditions, using two setups: a single vertical drain model and a multiple vertical drains model with three drains in a triangular arrangement. Barron’s radial consolidation theory and Asaoka’s observational method were adopted for consolidation settlement predictions and the estimation of the radial coefficient of consolidation. The multiple vertical drains model showed faster consolidation compared to the single vertical drain model, with reduced time to achieve 50% settlement. Field data closely matched laboratory results, with discrepancies attributed to soil heterogeneity and smear zone effects. The study found that optimized drain spacing and accurate selection of consolidation coefficients significantly improved prediction reliability. The results demonstrated the effectiveness of combining prefabricated vertical drains with preloading to accelerate settlement, reduce post-construction deformation, and enhance ground stability, offering valuable insights for future soft soil improvement projects.]]></description>
      <pubDate>Fri, 18 Jul 2025 09:05:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2573148</guid>
    </item>
    <item>
      <title>Nonlinear Consolidation of Stone Column-Vertical Drain Composite Foundations Incorporating Variable Well Resistance</title>
      <link>https://trid.trb.org/View/2559718</link>
      <description><![CDATA[A comprehensive investigation was conducted to elucidate the consolidation characteristics of composite foundations enhanced by stone columns combined with vertical drains. The effects of drain deflection and clogging on consolidation performance were systematically evaluated under a variable well resistance framework. A governing partial differential equation was formulated with the average excess pore water pressure as the primary variable. The corresponding analytical solution was subsequently developed. Comparative numerical analyses were conducted to evaluate the differences in consolidation and settlement rates between constant and variable well resistance models. The results demonstrated that neglecting well resistance variation leads to significant overestimation of consolidation and settlement rates as well as stone column stress concentration. The proposed model was validated through its application to an airport settlement prediction, showing improved consistency with in situ measurement data when adopting the variable well resistance model. ]]></description>
      <pubDate>Thu, 05 Jun 2025 13:30:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2559718</guid>
    </item>
    <item>
      <title>Design Curves for Time-Dependent Preloading Consolidation with PVDs Considering the Effects of Parabolic Permeability in the Smear Zone and Overlapping Smear Zones</title>
      <link>https://trid.trb.org/View/2516445</link>
      <description><![CDATA[The present research provides the design curves for preloading consolidation with prefabricated vertical drains that account for the effects of parabolic horizontal permeability distribution in the smear zone and the overlapping smear zones created by closely spaced drain systems. Additionally, the time-dependent application of surcharge preloading is also taken into consideration. When examining the overlapping of smear zones that result from the small spacing between drains, the results showed that in a triangular pattern, the ratios of the minimum center-to-center spacing between drains to the drain diameter are 1.52 and 10.85 for the smear zone size ratios of 2 and 20, respectively. The same ratios are 1.42 and 10.09 for a square pattern. The paper also outlines the design steps with an example. Ultimately, the implemented design curves are applied to the test embankments of the reclaimed Port of Brisbane to determine the design spacing. The results demonstrate that the predicted drain spacing, derived from the proposed design curves, closely aligns with the drain spacing used in the existing test embankments.]]></description>
      <pubDate>Tue, 27 May 2025 09:33:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2516445</guid>
    </item>
    <item>
      <title>Guide for Culvert and Storm Drain Rehabilitation

</title>
      <link>https://trid.trb.org/View/2558411</link>
      <description><![CDATA[Culvert and storm drain systems constitute critical nodes in U.S. transportation networks; however, many of these structures have met or exceeded their design service life. Replacing culverts under difficult constraints (i.e., high fills, high-volume roadways, difficult maintenance of traffic conditions) presents unique challenges causing transportation agencies to explore rehabilitation options. Much of the maintenance and restoration performed on buried structures is based on past practices and procedures in which state departments of transportation (DOTs) are familiar and experienced with implementing. 

Many times, standardized guidance for the rehabilitation design process is local. Meanwhile, new rehabilitation technologies continue to emerge without sufficient information on when and how they should be applied. The recent American Association of State Highway and Transportation Officials (AASHTO) Culvert and Storm Drain System Inspection Guide (CSDSIG) published in 2020 provides a roadmap for the inventory and inspection of culverts and storm drains. The next logical step is to determine a course of action for assets identified as deficient.  Research is needed to develop strategies for state DOTs on when to replace versus rehabilitate and the choice of a rehabilitation method.

OBJECTIVE: The objective of this project is to develop a guide for state DOTs for evaluating when to either replace or rehabilitate culverts and storm drains. The guide will also assist designers in the selection of the most appropriate rehabilitation method(s) along with the applicable loading conditions and design method to use when applying the chosen method. ]]></description>
      <pubDate>Tue, 27 May 2025 20:50:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2558411</guid>
    </item>
    <item>
      <title>Improving Culvert Performance with Diffusers and Energy Dissipators</title>
      <link>https://trid.trb.org/View/2558375</link>
      <description><![CDATA[Culvert and stormwater outfall performance presents challenges for hydraulic practitioners. Two challenges often encountered with culvert performance are inadequate capacity under outlet control and excessive energy at the downstream end of stormwater outfalls under inlet control. 

Previous research and applications have demonstrated that diffuser systems are a practicable option for increasing culvert and stormwater outfall capacity (see Special Note B). However, diffuser systems are an emerging technology, and additional methods and application guidelines are needed to support effective design and implementation. 

Current energy dissipator designs often result in large structures that are costly to construct and may require additional right-of-way. There is a need for design approaches that support more compact energy dissipator systems suitable for constrained right-of-way environments. It is important that such systems be adaptable for retrofitting existing culverts to mitigate scour issues. Advancements in computational fluid dynamics (CFD) modeling allow for efficient comparisons between initial prototype designs, saving time and money on physical modeling.

Research is needed to provide hydraulic practitioners with a design and application guide for implementing (1) diffuser systems to increase capacity, and (2) compact energy dissipator systems for retrofitting culverts. 

OBJECTIVE: The objective of this research is to develop a guide for the design and application of culvert diffuser and compact energy dissipator systems. The guide will give hydraulic practitioners the methods needed to deploy these systems in new and retrofit projects. ]]></description>
      <pubDate>Thu, 29 May 2025 12:56:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2558375</guid>
    </item>
    <item>
      <title>Ground Improvement by Prefabricated Vertical Drains and Surcharge for a Metro Depot Constructed on Marine Deposit</title>
      <link>https://trid.trb.org/View/2522042</link>
      <description><![CDATA[This paper focuses on field measurements, as well as analytical and numerical analyses conducted for a metro depot in Chennai, India, that employs prefabricated vertical drains (PVD) in conjunction with surcharge. The PVDs were installed in a triangular arrangement and extended to the bottom of the soft clay layer. Two PVD spacings of 1.2 m and 1.5 m were selected based on the site zone. Three surcharge fill heights—2.2 m, 3.0 m, and 3.6 m—were utilized, with the soil having a unit weight of 17 kN/m³. The surcharge was removed after 125 days, resulting in a maximum average settlement of approximately 150 mm. The monitoring data and analytical calculations confirmed the completion of primary consolidation. Both numerical simulations using commercial software and an analytical approach based on settlement and flow variables were employed to evaluate the scheme’s effectiveness. The analysis showed that the soft marine clay exhibited a high horizontal drainage capacity (C[subscript r]/C[subscript v] ratio between 4 and 22), which led to rapid settlement at the project site. Field measurement data were back-calculated to derive the consolidation settlement parameters. These findings could significantly impact future designs for ground improvement in the coastal region of South India.]]></description>
      <pubDate>Fri, 21 Mar 2025 09:03:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2522042</guid>
    </item>
    <item>
      <title>Characterization of Sediment Loads and Size Distributions in Nebraska Roadway Runoff - Phase 2</title>
      <link>https://trid.trb.org/View/2507239</link>
      <description><![CDATA[The goal of this project is to expand current research of sediment runoff (both concentrations and size distributions) from roadways to include data from additional districts and Municipal Separate Storm Sewer System (MS4) communities. The additional data will aid in more effective design of sediment removal systems so that installation and maintenance costs can be optimized. Because the design of inline sediment removal systems requires detailed information about sediment sizes and quantities, collection of data from four additional locations will improve the reliability of system installations so that they function well for MS4 communities in parts of the state that are distinct from those sampled during the initial project.]]></description>
      <pubDate>Mon, 10 Feb 2025 11:14:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/2507239</guid>
    </item>
    <item>
      <title>Wick Drain Research at an Illinois Project Site</title>
      <link>https://trid.trb.org/View/2228596</link>
      <description><![CDATA[Field research sponsored by the U.S. Federal Highway Administration was performed in conjunction with the Illinois Department of Transportation to determine the nature and extent of pore pressures induced by installing wick drains in saturated clay soil of high plasticity, and its effect on the rate and magnitude of embankment settlement. The findings were compared with the anticipated field performance of such installations based on accepted design practice. Dissipation of pore pressure induced by wick drain installation prior to embankment construction was found to be time dependent and occurred without soil settlement, factors not included in accepted consolidation theory. Total field settlement under embankment loading was consistent with settlement established by theory; however, time to dissipate 90% of induced pore pressure in the clay was found to be approximately 5 months longer than the 3 months established by accepted radial drainage theory. These findings were used to develop an empirical equation to correct the theoretical time for 90% primary consolidation to more accurately reflect the field performance based on the premise that wick drains remain fully functional until the required field consolidation is completed.]]></description>
      <pubDate>Sat, 28 Dec 2024 16:17:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2228596</guid>
    </item>
    <item>
      <title>The Evolution of Watertight Storm Drainage Systems</title>
      <link>https://trid.trb.org/View/2218592</link>
      <description><![CDATA[Watertight pipe and structures have historically only been considered with sanitary systems. The cost, however, of construction, maintenance, roadway safety and stream and groundwater contamination have united previous construction industry adversaries. Federal, state and municipal agencies, contractors, pipe and precast concrete producers, and design engineers all want watertight storm drainage systems. The reasons may vary but their overall goal in the same. Government agencies are having significant problems with non-point stream pollution, groundwater contamination, and de-watering of wet lands via leaking storm drainage systems. These agencies are starting to institute regulations to address these problems with possible ramifications on project designs. State DOTs and municipalities are implementing new specifications to address the effects of underground structural failures related to the leaking and piping of backfill materials through open. Contractor's, for their part, are also investigating the cost savings associated with quicker and lower priced watertight construction techniques. The final advocating group, the concrete precaster, is arguing for the benefit of a higher precast quality watertight product, over cast-in-place structures, with no additional cost to the owner. Specific examples from federal agencies, DOT's and cities indicate there is an evolution to watertight storm drainage systems. Financial arguments from the consulting engineers, contractors and precasters point of view demonstrate an alternate reasoning for this requirement. It appears the crest of a new design philosophy regarding storm drainage systems is emerging.]]></description>
      <pubDate>Wed, 18 Dec 2024 13:29:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2218592</guid>
    </item>
  </channel>
</rss>