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    <title>Research in Progress (RIP)</title>
    <link>https://rip.trb.org/</link>
    <atom:link href="https://rip.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>
    <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>Risk Assessment of Bridge Substructure due to Scour and Seasonal Moisture Variations
</title>
      <link>https://rip.trb.org/View/2696152</link>
      <description><![CDATA[Changes in flooding patterns, temperature extremes, and soil moisture cycles are intensifying the environmental loads acting on bridge infrastructure. These changes often result in more frequent and severe hydrologic events, potentially heightened vulnerability to structural failure of bridges. Scour, the erosion of soil around bridge piers and abutments due to increased streamflow during heavy rainfall, is a leading cause of hydraulic-related bridge failures. Similarly, soil moisture variability caused by extreme temperature and precipitation swings can compromise pile capacity, as soil stiffness decreases significantly under saturated conditions. These issues are particularly critical for Accelerated Bridge Construction (ABC) projects, where rapid construction methods must ensure longterm performance and resilience. Scour and soil moisture variations can accelerate foundation deterioration, compromising the integrity and safety of ABC bridges. Therefore, the proposed study aims to incorporate hydraulic hazard effects into the assessment of bridge substructure performance. Specifically, it will develop a comprehensive understanding of how the increasing frequency and intensity of hydraulic events influence bridge vulnerability, particularly the risk of damage caused by scour and seasonal variations in soil moisture. The research team will evaluate multiple Global Climate Models (GCMs) using different Shared Socioeconomic Pathway (SSP) scenarios to project future temperature and precipitation trends at selected study locations. Hydrologic modeling tools will be used to develop calibrated streamflow models using historical datasets of precipitation, temperature, and flow rates. Also, scouring depths at bridge foundations will be estimated following the HEC-18 procedures. These outputs will be integrated into a finite-difference model to study how scour and variations in soil moisture affect the lateral load behavior of bridge piles. The results will quantify failure probabilities, providing a comprehensive understanding of bridge resilience under changing hydraulic hazard conditions.]]></description>
      <pubDate>Mon, 27 Apr 2026 19:40:24 GMT</pubDate>
      <guid>https://rip.trb.org/View/2696152</guid>
    </item>
    <item>
      <title>Full-Scale Performance Evaluation of a Modular, Lightweight, UHPC Panel System for Repair of Corrosion-Damaged Steel H-Piles</title>
      <link>https://rip.trb.org/View/2695941</link>
      <description><![CDATA[This project directly supports the mission of the Center for Healthy and Durable Transportation (CHDT) by advancing innovative, implementable solutions to extend the service life of aging bridge infrastructure. The research focuses on developing and validating a modular, lightweight ultra-high-performance concrete panel system (UHPC-PS) for rehabilitating corrosion-damaged steel H-piles—critical substructure elements in United States bridges. By integrating advanced materials such as fiber-reinforced UHPC and carbon fiber reinforced polymer (CFRP) grids with practical field deployment strategies and full-scale performance validation under realistic service and seismic loading, the project enhances infrastructure durability, constructibility, long-term performance, and public safety, directly benefiting transportation agencies.]]></description>
      <pubDate>Thu, 23 Apr 2026 16:26:18 GMT</pubDate>
      <guid>https://rip.trb.org/View/2695941</guid>
    </item>
    <item>
      <title>CFST to Concrete Pile Cap Connections - Refinement of Analysis Methodologies and Standardization of Design Details</title>
      <link>https://rip.trb.org/View/2694292</link>
      <description><![CDATA[Concrete-filled steel tube (CFST) piles with concrete pile caps have been successfully used by the Montana Department of Transportation (MDT) as cost-effective bridge foundations for short and medium-span bridges. While their performance under gravity loads is well understood, predicting their behavior under extreme lateral loads (e.g. seismic events) remains challenging with conventional design methods. Recent research at Montana State University developed a moment-rotation based methodology to predict CFST-to-cap connection capacity, but refinements are needed to improve its accuracy, particularly
regarding the effects of U-bar reinforcement. Additionally, lack of standardized design details for CFST pile cap connections has led to inconsistencies in bridge designs and construction practices. Without standard details, engineers must custom-design each connection, which can result in variable performance and uncertain safety margins. There is a clear need to build upon the existing research findings to enhance the design methodology and provide uniform design guidance for these connections.]]></description>
      <pubDate>Fri, 17 Apr 2026 11:22:08 GMT</pubDate>
      <guid>https://rip.trb.org/View/2694292</guid>
    </item>
    <item>
      <title>SEAHIVE® solutions to mitigate bridge scour – Phase III (UM)</title>
      <link>https://rip.trb.org/View/2663128</link>
      <description><![CDATA[This is a collaborative research project conducted in partnership with Texas State University. Phases I and II of the project were conducted during AY24 and AY25. This one-year proposal is for Phase III of the three-phase project.  The objective of this research project is to show a proof-of-concept of using innovative hydraulic load dissipating elements, known as SEAHIVE®. This is a modular engineered protection system composed of concrete perforated hexagonal prisms. Perforations on the side faces of the elements provide passage for water flow dissipating the energy within the system while also adding structural complexity which improves its potential for habitat creation. 
SEAHIVE® has been under research and development at the University of Miami (UM) for wave energy dissipation and habitat enhancement with three pilot installations completed. This UTC study investigates the performance of the SEAHIVE® system intended for mitigating bridge scour. This project has the potential to create a consortium-wide effort for implementing the SEAHIVE® system into practice and changing how we design or retrofit bridge foundations for mitigating scour. Phase I focused on externally-prestressed elements given the mass production and scaling-up advantage. Externally prestressed (by Glass FRP rovings) units were produced by the dry-cast method with the same equipment used for the production of concrete pipes. Phase II focused on the production of internally-prestressed units using a revolutionary mold system. Using this technique, it will be possible to increase production efficiency and, as importantly, manufacture units of lengths up to 24 ft. that could be necessary for installation in riverine environments. The units produced with this technology were characterized.
Phase III deals with the production and characterization of elements made by wet-casting using a combination of randomly distributed short fibers for the control of cracking with and without the presence of transverse and longitudinal reinforcement made of GFRP bars. This investigation is made possible because of the special formwork that has recently been constructed as shown in Figure 1.
Figure1: Custom SEAHIVE® formwork 
The behavior of these units will be compared to others produced with the technologies investigated in the previous Phases I and II.]]></description>
      <pubDate>Sat, 31 Jan 2026 10:52:00 GMT</pubDate>
      <guid>https://rip.trb.org/View/2663128</guid>
    </item>
    <item>
      <title>Synthesis of Information Related to Highway Practices. Topic 57-03. Practice on Monitoring Scour Plan of Action for Bridges During and After Floods
</title>
      <link>https://rip.trb.org/View/2630487</link>
      <description><![CDATA[Scour is the most common cause of bridge failures. Per 23 CFR 650.313, state departments of transportation (DOTs) must have programs to manage the risks of scour vulnerability in their bridge inventories. Specifically, this regulation requires state DOTs to maintain a documented plan of action (POA) for every scour-critical bridge and every bridge with unknown foundations. A POA typically includes a plan for monitoring the bridge during or after flooding to ensure it is safe for traffic or closed if found to be unsafe.

The 23 CFR 650.313 does not prescribe specific monitoring methods, so state DOTs use a variety of approaches and software in their POAs. These approaches can vary depending on factors such as data availability, funding, and resources for scour monitoring. Therefore, a synthesis study documenting state DOT practices for meeting POA monitoring requirements for both on- and off-system bridges will help state DOTs implement monitoring scour POAs within their unique organizational contexts.

OBJECTIVE: The objective of this synthesis is to document state DOT practices and policies for POA implementation, including monitoring methods, software, instrumentation, and other tools used in these efforts.]]></description>
      <pubDate>Wed, 26 Nov 2025 16:33:27 GMT</pubDate>
      <guid>https://rip.trb.org/View/2630487</guid>
    </item>
    <item>
      <title>Utilizing historic geotechnical data for the development of state-specific design correlations - Part 1: Data Entry</title>
      <link>https://rip.trb.org/View/2607966</link>
      <description><![CDATA[The purpose of this innovative project is twofold, and the project will be broken into two parts. The first purpose is to organize historical geotechnical borehole data into a usable format. For each proposed bridge replacement that involves new foundation construction, the New Mexico Department of Transportation (NMDOT) Geotechnical Exploration Section typically completes at least one geotechnical boring at each substructure element (i.e., each pier and abutment). Approximately 2,000 digital files in the form of PDFs or Excel files, dating back to the early 2000s, can be found in the NMDOT Geotechnical Section share folder. However, the files are not in a format that can be easily tied to a geographic location or specific formation. This project will organize the historical data into the OpenGround database, currently used to log new boreholes or another DIGGS-compatible database. This could be incorporated into preliminary desk studies that are conducted in the early stages of new construction projects (Geotechnical Scoping Reports). It could also be used to supplement and support the data that is collected during the exploration phase of a design project, help fill in gaps in the data, and provide greater context for the type of material that is anticipated to be encountered during construction. Therefore, having this data available in the existing internally accessible OpenGround database would be a great asset to the Department. ]]></description>
      <pubDate>Thu, 09 Oct 2025 12:53:58 GMT</pubDate>
      <guid>https://rip.trb.org/View/2607966</guid>
    </item>
    <item>
      <title>Develop Guidance on Drilled Shaft Response to Collision Force</title>
      <link>https://rip.trb.org/View/2606400</link>
      <description><![CDATA[The 2024 AASHTO LRFD Bridge Design Specifications, 10th Edition, specify a 600-kip equivalent static force (ESF) for vehicle collisions with unprotected bridge columns. Current provisions assume this force transfers directly from the column to the foundation, often a drilled shaft, leading to potentially inadequately sized foundations. Field investigations show that drilled shafts rarely sustain impact damage; instead, failures typically occur at the column-to-drilled-shaft connections or the column. Additionally, the response of soil, concrete, and steel under high strain rates differs from static conditions, increasing material strength and stiffness. Nevertheless, current design provisions provide limited guidance on these dynamic effects, leading to uncertainty in impact load distribution and resistance. This study aims to enhance collision load modeling accuracy, ensuring that drilled shaft-supported bridge substructures are designed more efficiently while maintaining structural resilience. The outcomes will support Texas Department of Transportation (TxDOT) and 
American Association of State Highway and Transportation Officials (AASHTO) specification updates, optimizing foundation design and mitigating the risk of premature failures at critical connections.]]></description>
      <pubDate>Thu, 02 Oct 2025 09:47:40 GMT</pubDate>
      <guid>https://rip.trb.org/View/2606400</guid>
    </item>
    <item>
      <title>Scour Critical Shear Stress of Ohio Soils
</title>
      <link>https://rip.trb.org/View/2601291</link>
      <description><![CDATA[Currently, Ohio Department of Transportation (ODOT) assumes all cohesive soils to be granular soil with the same gradation as fine Ottawa sand, which is the most scourable soil material. This is an unreasonable assumption for cohesive soils, and it over-predicts scour to an unrealistic degree, potentially costing Ohio from a few thousand to millions of dollars per bridge foundation at water crossing structures with cohesive foundation soils. According to the Federal Highway Administration (FHWA) "NextScour" program, "The result of this assumption can be too conservative when soils other than the uniformly graded granular soils are encountered and can dramatically increase the cost of many bridge foundations."

ODOT needs to develop reasonable scour guidelines and analyses based on soil scour critical shear stress (tc) to provide realistic predictions of scour depth for scour design floods and scour check floods, so that appropriately efficient and economical foundations can be designed for Ohio bridges. ODOT needs an economical and practical way to estimate tc for input into scour analyses, based on common laboratory soil testing index properties, without the need to resort to expensive and time-consuming flume soil testing to measure tc for each project.

ODOT proposes to develop better soil scour guidelines and analyses based on scour critical shear stress (tc), including estimation of tc based on common laboratory soil testing index properties through this study.
                          ]]></description>
      <pubDate>Wed, 17 Sep 2025 08:35:07 GMT</pubDate>
      <guid>https://rip.trb.org/View/2601291</guid>
    </item>
    <item>
      <title>Phase II: Method Development for Construction Design in Diatomaceous Soils</title>
      <link>https://rip.trb.org/View/2594023</link>
      <description><![CDATA[Diatomaceous soils, which contain silica frustules from ancient algae blooms, are prevalent in eastern and central Oregon, including in areas of Oregon Department of Transportation (ODOT) right-of-way. For engineering projects built on top of or in these deposits, problems such as excessive settlement of embankments, slope instability, and construction difficulties with drilled shafts and driven piles have been observed (ex. Wickiup Junction, Buck Creek Bridge). Lack of a robust understanding of the behavior of diatomaceous soils is often cited as the reason for this poor design performance. Complicating matters further, relatively little is documented in the literature regarding the performance of piles in diatomaceous soils. To begin to understand the behavior of diatomaceous soils, ODOT recently invested in a research program (SPR820) to develop predictive estimating models for geotechnical properties of Oregon’s diatomaceous silt, leveraging available data from existing ODOT diatomaceous projects together with targeted field-directed geotechnical testing including an array of in-situ tests at select sites in diatomaceous deposits. These materials have been further characterized through an extensive laboratory testing program. A full-scale field test is now required to develop and validate necessary empirical design methods for deep foundations in diatomaceous silt.]]></description>
      <pubDate>Thu, 28 Aug 2025 15:33:18 GMT</pubDate>
      <guid>https://rip.trb.org/View/2594023</guid>
    </item>
    <item>
      <title>Combined Inertial and Lateral Spread Demands for Deep Foundations 



</title>
      <link>https://rip.trb.org/View/2558398</link>
      <description><![CDATA[In certain regions of the United States, highway bridge foundations may be subject to (1) lateral spreading demands due to liquefaction or cyclic softening of native soils adjacent to deep foundations (i.e., kinematics) and (2) inertial demands during shaking due to structure mass. There is no consensus in design codes on how to combine inertial and kinematic demands. The American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design Bridge Design Specifications recommend designing deep foundations for the simultaneous effects of inertia and lateral spreading only for large magnitude earthquakes. The combination of inertial and earthquake-induced kinematic demands appears to be a site- and project-specific phenomenon affected by the type of foundations (e.g., small-diameter piles vs. large-diameter shafts), the dynamic response of the structures (e.g., bridge deck response in the longitudinal and transverse directions and the restraining effects of the approach embankments on the global response of the superstructure), and ground motion characteristics (e.g., subduction vs. shallow crustal motions with varying durations). Research is needed to characterize the inertial and kinematic demand combination factors for highway bridges and propose revisions to the current design requirements.

OBJECTIVE: The objective of this research is to develop combination factors (i.e., inertial and kinematic) for bridge deep foundations subjected to inertial (e.g., structural dynamics) and earthquake-induced ground deformation (e.g., liquefaction, strain softening, cyclic mobility) demands.]]></description>
      <pubDate>Wed, 28 May 2025 10:06:55 GMT</pubDate>
      <guid>https://rip.trb.org/View/2558398</guid>
    </item>
    <item>
      <title>Design and Analysis of Bridge Foundations for Redundancy

</title>
      <link>https://rip.trb.org/View/2558400</link>
      <description><![CDATA[The American Association of State Highway and Transportation Officials (AASHTO) approach for designing highway bridges and structures addresses uncertainty in load and resistance and quantifies the variability in design parameters. However, from a geotechnical perspective, foundation design has typically involved calibrating design methods to a target reliability index (β) correlated to the probability of failure, which was considered acceptable in past practice. For example, the reliability index for deep foundation design has been calibrated for probabilities of failure of 1 in 100 (β = 2.3) for driven piles and 1 in 1,000 (β = 3.0) for drilled shafts. This difference is believed to be attributed to the variation in reliability between individual foundation elements and pile groups, with the latter being considered highly redundant systems.

The current AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications (BDS) are ambiguous regarding the definition of redundancy and its application to foundations. Research is needed to investigate redundancy as it applies to geotechnical design and to enhance existing design and analysis requirements.

The objective of this research is to develop design and analysis requirements for bridge foundation elements and groups. These requirements shall account for redundancy based on a probabilistic consideration of resistance for foundations.]]></description>
      <pubDate>Wed, 28 May 2025 10:00:22 GMT</pubDate>
      <guid>https://rip.trb.org/View/2558400</guid>
    </item>
    <item>
      <title>Field Durability survey and Evaluation of Drilled Shafts and ACP Piles</title>
      <link>https://rip.trb.org/View/2536236</link>
      <description><![CDATA[The primary objective of the study is to determine if there are significant safety and durability issues for structural concrete structures that may have demonstrated thermal cracking and/or mattressing defects. Understanding if and/or when undesirable consequences occur will lead to the ability to recommend changes in construction practices or material composition (i.e. concrete mix designs) to increase reliability and longevity of future Florida Department of Transportation (FDOT) concrete structures.]]></description>
      <pubDate>Fri, 11 Apr 2025 09:34:27 GMT</pubDate>
      <guid>https://rip.trb.org/View/2536236</guid>
    </item>
    <item>
      <title>Roadway Foundation Cooling using Structured Foam Layers</title>
      <link>https://rip.trb.org/View/2512616</link>
      <description><![CDATA[This project seeks to evaluate cost-effective solutions to reduce permafrost thaw and resulting embankment deformation. Specifically, evaluating structured foam layers to result in net annual cooling effect and testing designs in a laboratory setting. This project will evaluate solutions optimizing proposed geometries to reduce the height of structured foam layers, thus reducing cost. This study could also lead to design guidelines that 
Alaska Department of Transportation and Public Facilities (DOT) or other design engineers could use in design.]]></description>
      <pubDate>Fri, 21 Feb 2025 21:06:12 GMT</pubDate>
      <guid>https://rip.trb.org/View/2512616</guid>
    </item>
    <item>
      <title>Accelerated Bridge Construction (ABC) Methods for Pile-Footing-Column Systems</title>
      <link>https://rip.trb.org/View/2509057</link>
      <description><![CDATA[
Building on a previous project, the proposed research will advance the accelerated bridge construction method for bridge substructures using steel piles and precast pile caps and columns. The weight of the precast members will be reduced using hollow sections, which in turn will improve both construction tolerances and constructability. The hollow sections will be filled with in-situ concrete. The piles will be designed with temporary collars, which will eliminate the need to wait for the concrete to cure before continuing with the superstructure construction. The proposed research, funded jointly by the California Department of Transportation, will include a large-scale test unit which will incorporate both vertical and battered steel piles. The testing of the system will incorporate service level and extreme loads and ensure dependable performance of the new system and its components. As part of the testing program, the performance of the column and pile foundations will be examined systematically. Analytical models will be developed to realize the observed performance of the test unit and the components. Using the combination of analytical and experimental observations and findings from the previous phase of the project, appropriate design recommendations will be developed for improving bridge construction.]]></description>
      <pubDate>Wed, 12 Feb 2025 18:34:48 GMT</pubDate>
      <guid>https://rip.trb.org/View/2509057</guid>
    </item>
    <item>
      <title>Accelerated Bridge Construction (ABC) Methodology for Integral Abutments</title>
      <link>https://rip.trb.org/View/2509055</link>
      <description><![CDATA[Building on a previous bridge substructure project, the proposed research will advance the accelerated bridge construction method for integral bridge abutments supported on steel piles and constructed using prefabricated and in-situ concrete along with other advanced construction techniques (3D printing) and materials as appropriate. The weight of the prefabricated members will be reduced using hollow or shell elements, which in turn will improve both construction tolerances and constructability. The hollow sections will be filled with in-situ concrete. The piles will be designed with temporary collars, which will eliminate the need to wait for the concrete to cure before continuing with the assembly of the abutment and placement of the girders. The proposed research, funded jointly by the California Department of Transportation, will include two large-scale outdoor test units, which will incorporate both vertical and battered steel piles. One test unit will model an integral abutment while the second unit will replicate a seat type abutment with other details. The testing of the system will incorporate service level and extreme loads and ensure dependable performance of the new system and its components. As part of the testing program, the performance of the abutments will be examined systematically. Analytical models will be developed to replicate the observed performance of the test unit, the components and the connections. Using the combination of analytical and experimental observations and findings from the previous phase of the project, appropriate design recommendations will be developed for improving bridge construction.]]></description>
      <pubDate>Wed, 12 Feb 2025 18:06:19 GMT</pubDate>
      <guid>https://rip.trb.org/View/2509055</guid>
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