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    <title>Research in Progress (RIP)</title>
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    <atom:link href="https://rip.trb.org/Record/RSS?s=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSJhbGwiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMTYiIC8+PC9wYXJhbXM+PGZpbHRlcnM+PGZpbHRlciBmaWVsZD0iaW5kZXh0ZXJtcyIgdmFsdWU9IiZxdW90O0dlb3RleHRpbGVzJnF1b3Q7IiBvcmlnaW5hbF92YWx1ZT0iJnF1b3Q7R2VvdGV4dGlsZXMmcXVvdDsiIC8+PC9maWx0ZXJzPjxyYW5nZXMgLz48c29ydHM+PHNvcnQgZmllbGQ9InB1Ymxpc2hlZCIgb3JkZXI9ImRlc2MiIC8+PC9zb3J0cz48cGVyc2lzdHM+PHBlcnNpc3QgbmFtZT0icmFuZ2V0eXBlIiB2YWx1ZT0icHVibGlzaGVkZGF0ZSIgLz48L3BlcnNpc3RzPjwvc2VhcmNoPg==" 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>
    <image>
      <title>Research in Progress (RIP)</title>
      <url>https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg</url>
      <link>https://rip.trb.org/</link>
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    <item>
      <title>Enhancing Transportation Safety through Moisture Control Using Wicking Geotextiles in Pavement Systems</title>
      <link>https://rip.trb.org/View/2703923</link>
      <description><![CDATA[Excess subsurface moisture is a primary cause of pavement deterioration, contributing to frost heave, thaw weakening, pumping, stiffness loss, and surface roughness. These moisture-driven mechanisms compromise roadway safety by reducing vehicle stability, braking performance, and ride quality, while increasing maintenance frequency and costs. Wicking geotextiles are an emerging geosynthetic technology designed to actively remove both gravity and capillary water from pavement systems without external energy input. By transporting moisture laterally toward pavement shoulders and releasing it through evaporation, these materials help maintain drier and more stable subgrade conditions. Previous laboratory studies and field applications have demonstrated their technical feasibility and cost-effectiveness; however, current implementation remains largely empirical due to the lack of a mechanistic design framework.
This project aims to develop a fully coupled thermo–hydro–mechanical (THM) modeling framework to quantify the moisture-removal capacity of wicking geotextiles and evaluate their impact on pavement performance under unsaturated and freezing conditions. The research integrates laboratory characterization of soil–geotextile systems, controlled freezing tests to assess frost-heave mitigation, and advanced numerical modeling grounded in modern unsaturated soil mechanics. The validated model will be used to conduct parametric studies examining soil type, groundwater level, environmental loading, and installation configuration.
The expected outcomes include a validated THM model, quantitative evaluation tools for moisture control effectiveness, and practical, safety-oriented design guidance for transportation agencies. By transforming wicking geotextiles into a design-ready technology, this project will support safer, more resilient, and cost-effective pavement infrastructure.]]></description>
      <pubDate>Wed, 20 May 2026 09:19:26 GMT</pubDate>
      <guid>https://rip.trb.org/View/2703923</guid>
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    <item>
      <title>SPR-5032: Moisture Damage Control and Mitigation in Pavement Foundations Using Innovative Geosynthetics</title>
      <link>https://rip.trb.org/View/2577102</link>
      <description><![CDATA[This project is primarily about controlling water in pavement foundation layers for increased pavement performance. This study proposes to remove water out of the pavement systems via use of geotextile fabric (moisture management geotextile) as a separation layer in pavement foundation systems to mitigate the damage that occurs due to high moisture contents. The workplan consists of constructing sites with these innovative geosynthetics and conducting field tests and analyses. The field tests will include lightweight deflectometer, falling weight deflectometer, moisture and temperature monitoring through depth.]]></description>
      <pubDate>Thu, 17 Jul 2025 15:57:29 GMT</pubDate>
      <guid>https://rip.trb.org/View/2577102</guid>
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    <item>
      <title>Assessing Wicking Geotextile for Enhanced Drainage and Stability in Highway Slopes: A Field Study in Central Texas</title>
      <link>https://rip.trb.org/View/2509301</link>
      <description><![CDATA[Highway slope failures are a significant geo-environmental hazard, disrupting transportation networks, causing costly repairs, delays, and endangering lives. Rainfall is a key contributor to these failures, reducing soil shear strength through infiltration. As extreme weather events intensify, there is a growing need for effective drainage solutions to enhance slope stability and ensure transportation infrastructure resilience. Multifunctional wicking geotextiles, known for their moisture redistribution capabilities, have emerged as a promising solution for improving slope stability by facilitating water drainage. This study builds on the previous SPTC project, ‘Multifunctional Geosynthetic-Based Stabilization to Increase Coastal Infrastructure Resilience’, which evaluated wicking geotextiles in laboratory settings. 
The current research aims to assess the field performance of wicking geotextiles in reinforced highway slopes through full-scale tests. Test sections will be constructed in central Texas, using both conventional and wicking geotextiles. A comparative analysis will focus on drainage efficiency and slope stability, particularly under extreme weather conditions. Data on soil moisture and slope deformation will be collected using moisture sensors and remote sensing technologies, such as Synthetic Aperture Radar (SAR) and Unmanned Aerial Vehicles (UAVs). 
The objectives of this study will be accomplished through 5 tasks. Task 1 involves literature review and material procurement. Task 2 involves site selection and soil sample collection. Characterization of engineering properties of soil will be pursued in Task 3. Task 4 will involve design and construction of test sections. Task 5 involves monitoring of slope and data analysis. This study will provide critical insights into the long-term performance of wicking geotextiles, contributing to the development of more resilient and sustainable transportation infrastructure capable of withstanding extreme weather events.

]]></description>
      <pubDate>Thu, 13 Feb 2025 15:04:06 GMT</pubDate>
      <guid>https://rip.trb.org/View/2509301</guid>
    </item>
    <item>
      <title>Quantify the Benefits of Using Geotextiles and Geogrids to Improve the Performance of Unbound Pavement Layers</title>
      <link>https://rip.trb.org/View/2422990</link>
      <description><![CDATA[Geotextiles and geogrids are the most used geosynthetics in transportation/pavement applications. Geotextiles can reduce layer intermixing, facilitate moisture reduction, and provide confinement and stabilization to subgrade and base materials. Geogrids provide mechanical stabilization by giving strength to base and full depth reclamation material through lateral restraint and improved load bearing capacity in pavement systems. The main objective of the study is to produce a current best practices design guide for road designers detailing when to use and what types of geotextiles and geogrids to use for given soil, pavement designs, and traffic conditions. Having a guide will aid designers in utilizing these products to better predict pavement outcomes and to extend pavement life. The project tasks include (1) evaluating current Minnesota Department of Transportation
(MnDOT) practice related to the beneficial and cost-effective use of geosynthetics; (2) reviewing research and state of the practice on geosynthetics applications, available products, design methods, and specifications; and (3) proposing recommendations for geosynthetic solutions in pavements to modernize MnDOT’s practices and manuals. The study will highlight current best practices and produce a synthesis report and a Technical Guide for using geotextiles and geogrids based upon soil type, pavement structure, and traffic loads, etc. This will include quantification of these benefits based upon the functions of the geotextile, i.e., separation, filtration, drainage, and stiffening or stabilization, and for geogrids, stabilization of aggregate cover over soft subgrade in unpaved roads and paved road unbound aggregate layer stabilization that will include the strength gain of the base or full depth reclamation material. ]]></description>
      <pubDate>Fri, 30 Aug 2024 10:00:43 GMT</pubDate>
      <guid>https://rip.trb.org/View/2422990</guid>
    </item>
    <item>
      <title>Implementation of Semi-integral Bridges in Texas</title>
      <link>https://rip.trb.org/View/2342165</link>
      <description><![CDATA[The research team will validate predicted semi-integral bridge performance against actual semi-integral bridge performance; particularly regarding backfill placement requirements. In particular, the geotextile-confined backfill will be monitored to assess its impact on (1) the lateral earth pressures induced due to cycles of temperature-induced backfill movements and (2) the settlements of the backfill material. The new approach, developed in research project 0-6936, is expected to reduce lateral earth pressures and decrease settlements. This validation of field performance will facilitate the development of a standard detail and commentary for the Bridge Design Manual as well as the compilation of additional design and construction guidelines. The research team will also monitor the semi-integral bridge at China Creek, in the Wichita Falls District using the wireless field monitoring system installed during research project 0-6936.]]></description>
      <pubDate>Tue, 20 Feb 2024 15:49:50 GMT</pubDate>
      <guid>https://rip.trb.org/View/2342165</guid>
    </item>
    <item>
      <title>Quantifying Soil Moisture Reduction by Wicking Geotextile to Minimize Pavement Distresses</title>
      <link>https://rip.trb.org/View/2341500</link>
      <description><![CDATA[Excessive moisture in pavement foundations including base courses and subgrade is one of the major causes for pavement distresses, which often pose safety risks to vehicles and drivers and increase the cost for maintenance and reconstruction. Moisture can weaken pavement foundations and become a source for freeze-thaw problems in cold regions, which accelerate the deterioration of pavements with time. Therefore, pavement drainage is critical to pavement performance. Typical drainage systems are effective for saturated soils but become less effective or ineffective for unsaturated soils. Wicking geotextile that contains deep-grooved fibers can generate suction when in contact with water and reduce moisture in unsaturated soils. However, the effectiveness of the wicking geotextile in reducing moisture depends on several factors including the percent of fines in soils. So far, no simple test method is available to evaluate the effectiveness of the geotextile in reducing moisture in soils including those with fines and no fine content limit has been established for the wicking geotextile to be effective.  The proposed research is to develop a simple soil box test to quantify the effectiveness of the wicking geotextile in reducing moisture in sands at different fine contents and distances from the geotextile as compared with the conventional geotextiles. The soil box tests will first determine field capacities of silty sands at different fine contents and then evaluate moisture reduction by geotextiles by measuring moisture contents at different distances from the geotextile location at different times. These tests will determine the amount of moisture reduction and the distance of influence, and the fine content limit for the geotextile to be effective. The objective of this research is to develop a simple test method to quantify soil moisture reduction by geotextile and provide guidance for its use in sands with fines.  ]]></description>
      <pubDate>Sat, 17 Feb 2024 16:20:34 GMT</pubDate>
      <guid>https://rip.trb.org/View/2341500</guid>
    </item>
    <item>
      <title>Multifunctional Geosynthetic-based Stabilization to Increase Coastal Infrastructure Resilience</title>
      <link>https://rip.trb.org/View/2265858</link>
      <description><![CDATA[Coastal communities of Texas and Louisiana primarily rely on road infrastructure for their transportation and access to goods and services. Due to surges in extreme rainfall and storm events, coastal infrastructure is at pressing risk. The aggressive infiltration of water in the pavement due to frequent flooding declines its functional and structural performance gradually. Geosynthetics have been extensively used in pavement structures to enhance their bearing capacity and stiffness. Most of the commonly used geosynthetics do not help with subsurface drainage under pavements. A novel geotextile with special hydrophilic and hygroscopic wicking fibers is gaining popularity due to its multiple functions, including separation, reinforcement, gravity drainage, and capillary drainage through wicking action. Because of its versatility, it can potentially serve as a unified drainage and reinforcing element in a pavement.
This project aims to assess wicking geotextile as a resilient adoption in coastal pavement infrastructure vulnerable to the impacts of changing weather patterns. The objectives of this research study are: (1) To understand the efficacy of wicking geotextile reinforcement in pavement infrastructure under extreme weather conditions; (2) To compare the overall performance of wicking geotextile with conventional geotextile reinforcement in coastal pavements. 
To address these objectives, the following research tasks will be conducted: (1) Existing literature on novel geosynthetics and their characterization will be reviewed and summarized in progress reports and in the final report; (2) Moisture movements within a soil layer with wicking geotextiles and conventional geotextiles will be studied. Moisture probes or tensiometers will be installed in the large direct shear box, and moisture variation in compacted soil will be recorded for up to 7 days. This will help understand and compare drainage capabilities of conventional and wicking geotextiles under different normal loads; (3) Around 20 large-scale direct shear tests (apparatus shown in Figure 1) will be performed on soil with wicking geotextile and conventional geotextile to determine interface friction angle and cohesion. Tests will be performed at different normal loads after 3 and 7 days of drainage. The experimental results will potentially provide a degree of increase in the strength of the subgrade with an application of wicking geotextile; (4) A fully coupled finite element model of coastal pavement infrastructure reinforced with both geotextiles under different environmental stressors will be developed. Laboratory results will be used to develop a model in PLAXIS, and the performance of wicking geotextile in pavements will be assessed under extreme rainfall and flooding events. 
]]></description>
      <pubDate>Sat, 14 Oct 2023 07:26:43 GMT</pubDate>
      <guid>https://rip.trb.org/View/2265858</guid>
    </item>
    <item>
      <title>Comparing the Performances of Different Wicking Fibers for Water Removal for Transportation Applications</title>
      <link>https://rip.trb.org/View/1868761</link>
      <description><![CDATA[The goal of the proposed research is to better understand the working mechanism of different wicking fibers by quantifying and comparing their water-removing ability. About 12 wicking fibers with different wicking fibers will be evaluated through the scanning electron microscope (SEM), capillary rise, zero gradient flow, permeability, and small -scale laboratory model tests. Numerical simulation will be performed to better understand the working mechanism of the wicking fibers. All the test results will be combined and analyzed using machine learning techniques to generate a model to correlate the water removal ability of the wicking fibers and different influence factors. The ultimate goal is to provide guidelines for producing the next generation of wicking geotextile with higher water removal efficiency.]]></description>
      <pubDate>Tue, 27 Jul 2021 18:27:06 GMT</pubDate>
      <guid>https://rip.trb.org/View/1868761</guid>
    </item>
    <item>
      <title>Numerical Simulation of Pavement Installed with Wicking Geotextile in Responses to Climatic Conditions</title>
      <link>https://rip.trb.org/View/1743190</link>
      <description><![CDATA[Several field applications and laboratory research have identified the short-term benefits of a multi-functional wicking geotextile in removing water from the soil and improving pavement performance. In line with an on-going project to continuously monitor field performance of pavement with applications of wicking geotextile, this project aims to further understand the working mechanism of the wicking geotextile under field conditions through numerical simulation, and to quantify its benefits into existing pavement design. The expected research results will be a coupled thermo-hydro-mechanical model that can depict the climate-plant-unsaturated soil infrastructure interactions, numerical simulation results of wicking geotextile long-term performance under different climatic conditions, and recommendations on incorporating the wicking geotextile benefits into current pavement design guides. The proposed research will contribute to developing an effective, sustainable approach for pavement preservation using new materials and technology, which will benefit extending pavement life, and producing significant saving to the State and Federal funding on repair and maintenance.]]></description>
      <pubDate>Tue, 06 Oct 2020 10:08:29 GMT</pubDate>
      <guid>https://rip.trb.org/View/1743190</guid>
    </item>
    <item>
      <title>Extended Monitoring of Performance of Wicking Geotextile to Mitigate Pumping in Pavement Shoulder</title>
      <link>https://rip.trb.org/View/1742802</link>
      <description><![CDATA[In a recently completed project, a full-scale test section located along I-44 highway in Missouri was constructed and monitored to investigate the effect of a new type of wicking geotextile to enhance pavement drainage and mitigate water pumping. Analyzing one year of data acquired from the sensors shows that the wicking geotextile has successfully reduced the volumetric water content of the base course material up to 5%-10% and enhanced the pavement drainage capacity. Observations showed that the efficiency of wicking geotextile is considerably better than conventional drainage systems including French drains when the pavement is under unsaturated condition. The main objective of this project is to maintain the data collection system at the I44 test sections and continue to monitor the long term performance of the H2Ri wicking fabric at the test site in the next three years. The expected research results will be field monitoring data, and associated findings and recommendations on using H2Ri wicking fabric in addressing durability related issues in pavement system, which will benefit pavement longevity and significantly reduce the State budget on repair and maintenance.]]></description>
      <pubDate>Mon, 05 Oct 2020 17:07:21 GMT</pubDate>
      <guid>https://rip.trb.org/View/1742802</guid>
    </item>
    <item>
      <title>SPR-4116: Investigation of Design Alternative for the Subbase of Concrete Pavements</title>
      <link>https://rip.trb.org/View/1445903</link>
      <description><![CDATA[The study will develop recommendations for new subbase designs based on a comprehensive review of the literature, a survey of best practices across the US and abroad and an experimental program focused on unstabilized layers alone and in combination with geotextiles.]]></description>
      <pubDate>Thu, 19 Jan 2017 13:20:52 GMT</pubDate>
      <guid>https://rip.trb.org/View/1445903</guid>
    </item>
    <item>
      <title>Practical Design Guidelines for Replacement of Deficient Bridges with Low-Water Stream Crossing in the Rural Midwest</title>
      <link>https://rip.trb.org/View/1366524</link>
      <description><![CDATA[This project will produce a report that provides practical engineering guidance for the replacement of deficient bridges with low-water stream crossings in the rural Midwest.  The report will address the following issues: (1) site assessment and economics; (2) selection of crossing type -- the two basic types of low-cost low-water crossings are the unvented ford and the vented ford; (3) design of roadway profile and culvert pipes; (4) selection of crossing materials -- low-water crossings can be built of concrete, crushed stone, natural stone, stone reinforced with geogrid or geotextile, stone-filled gabions and other materials; and (5) general design details.  The project will provide guidelines for materials selection, provide general design details for unvented fords and vented fords constructed of different materials, and also  provide guidance on signage of low-water crossings.]]></description>
      <pubDate>Sat, 22 Aug 2015 01:00:37 GMT</pubDate>
      <guid>https://rip.trb.org/View/1366524</guid>
    </item>
    <item>
      <title>Numerical Study of Geosynthetic-Aggregate Interaction Under Wheel Loading</title>
      <link>https://rip.trb.org/View/1228256</link>
      <description><![CDATA[Interaction between geosynthetics (geogrid or geotextile) and aggregates under traffic wheel loading has been considered as one of high-priority problems by the Transportation Research Board. The practical use of geosynthetics above the subgrade or in base course has demonstrated their effects on the reduction of rut depths and the prolonging of pavement life. Continuum mechanics treats aggregates as a continuum media, which cannot properly simulate the movement and interaction of aggregates with geosynthetics. The proposed research will investigate this interaction using a numerical software - particle flow code (PFC), which is based on micromechanics. Micromechanics assume that aggregates are a granular assembly, in which stresses are transmitted by contacts between grains, each of which has a different direction. The numerical study will investigate the mechanisms involved in the interaction between geosynthetics and aggregate and provide guidance for the selection of geosynthetics and aggregates and the design of geosynthetic-reinforced base course under traffic wheel loading.]]></description>
      <pubDate>Thu, 03 Jan 2013 13:17:32 GMT</pubDate>
      <guid>https://rip.trb.org/View/1228256</guid>
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