Engineering Commons^™

Evaluation Of Ndot’S Sediment Barrier Practices Using Performance Data, Michael A. Perez, Wesley N. Donald, J. Blake Whitman, Brian G. Roche

Nebraska Department of Transportation: Research Reports

To protect waterways adjacent to construction projects with disturbed land, a 50 ft (15 m) vegetated buffer or equivalent sediment controls are required. However, there is little guidance on the effectiveness of vegetated buffers in removing sediment or how sediment barriers can aid shorter buffers or replace buffers. A modeling methodology was developed and used to determine the performance of 11,664 50 ft (15 m) vegetated buffer configurations with Nebraska conditions; sediment capture averaged 92.6% and ranged from 18.5% to 99.5%. To determine the performance of Nebraska Department of Transportation standard and modified sediment barrier installations, a large-scale testing methodology …

Erosion Resistant Rock Shoulder, Chung R. Song, Richard L. Wood, Basil Abualshar, Mark O'Brien, Bashar Al-Nimri, Mitra Nasimi

Nebraska Department of Transportation: Research Reports

Highway shoulder rocks are exposed to continuous erosion force due to unexpected floodings caused by climate change. The evaluation methods of the erosion resistance of highway shoulder rocks are not currently well-developed. This study developed a new large-scale testing device, the University of Nebraska-Lincoln Erosion Testing Bed (UNLETB), which has the capability of testing the shoulder gravels. Different gradations were tested using UNLETB, and the results distinguished a high-resistant group and a low-resistant group. The low resistant group was treated with different binding agents: Ammonium Lignosulfonate (LIGNO10), Soybean Soap Stock, and DirtGlue. The treated samples showed better erosion resistance based …

Truck Platooning Effects On Girder Bridges: Phase Ii-Service, Joshua Steelman, Jay Puckett, Daniel Linzell, Bowen Yang

Nebraska Department of Transportation: Research Reports

Truck platooning—wirelessly linking two or more trucks to travel in a closely spaced convoy—is federally promoted to save fuel, improve the environment, and improve traffic operations. Platooning places trucks much closer than current design codes anticipate. While this strategy can provide higher fuel efficiency, it also can potentially overload structures. Previous reliabilitybased studies (Steelman et al., 2021; Yang et al., 2021) have focused on the Strength I limit state and have shown that trucks can operate at weights exceeding standard legal load limits even with short headways at operating-level reliability. However, service limit states in the AASHTO LRFD Bridge Design …

Crashworthy Perforated Square Steel Tube (Psst) Mailbox Support – Phase I, Robert W. Bielenberg, Cody S. Stolle, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

Federal requirements have made it mandatory that safe mailbox support systems be designed to yield or breakaway whenimpacted by a vehicle. The Nebraska Department of Transportation (NDOT) has previously used a non-proprietary, U-channel post mailbox support that was evaluated at the Midwest Roadside Safety Facility (MwRSF) in the 1980's. NDOT desires that the mailbox support be updated to meet MASH 2016 TL-3 safety performance criteria and be redesigned to use perforated square steel tubing (PSST) for the mailbox support post.

The objective of this research project is to develop a non-proprietary mailbox support using PSST support posts that is MASH …

Nebraska Balanced Mix Design – Phase I, Farzad Yazdipanah, Mahdieh Khedmati, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

Balanced mix design (BMD) is an alternative concept for designing asphalt mixtures that mainly focuses on performance of mixtures rather than only volumetric analysis. Using this concept, it would be possible to account for the incorporation of recycled asphalt mixtures, warm technology, polymers, rejuvenators, and other foreign additives, as well as external effective factors on the mix design such as environmental effects. This project sought to investigate performance-based methodologies for the asphalt mix design by taking a step to develop a preliminary Nebraska BMD framework. With that, selection of appropriate performance tests, finding a functional laboratory aging protocol, and defining …

Inventory, Operations, And Safety At Free Right-Turn Ramps, Aemal Khattak, Jonathon Camezind, Mm Shakui Haque

Nebraska Department of Transportation: Research Reports

This research focused on traffic safety and operational performance of rural, minor approach stop-controlled intersections with free right-turn (FRT) ramps. The objectives of the research were to:

• Create a statewide inventory of rural FRT ramp intersections and provide to the Nebraska Department of Transportation (NDOT),
• Using NDOT 10-year crash data, conduct statistical safety analysis of rural FRT intersections extending ¼-mile in each direction from the intersection,
• Study vehicular operations at rural intersections with and without FRT ramps including a comparison of vehicular conflicts, and
• Develop guidelines for operations and safety tradeoffs to assist with NDOT projects on maintaining similar locations, …

Feasibility Study: Application Of Steel Sheet-Piles For The Abutment Of Water-Crossing Bridges In Nebraska, Seunghee Kim, Jongwan Eun, Chung R. Song, Chungwook Sim, Hung Phi Van, Basil Abualshar, Ramin Ziaei Tabari

Nebraska Department of Transportation: Research Reports

The overall goal of this study is to investigate the anticipated performance of steel sheet-pile bridge abutments to encourage its wider application to not only new construction but also repair and replacement of existing water-crossing bridges in Nebraska. For this purpose, this study first reviewed several bridge cases with axially loaded sheet pile abutments, as well as previous in-depth studies related to the bearing capacity of sheet piles. Then, this study conducted the large-scale direct shear tests to better understand the interaction between sheet pile and soil. As a result, about four-fifths of the internal friction angle of fill sand …

Establishment Of Wildflower Islands To Enhance Roadside Health, Ecological Value, And Aesthetics Phase Ii, Jackson Ebbers, Heidi L. Hillhouse, John A. Guretsky, Thomas J. Weissling

Nebraska Department of Transportation: Research Reports

No abstract provided.

Research And Education For Optimizing The Development And Implementation Of An Unmanned Aircraft Program At The Nebraska Department Of Transportation, Wayne Woldt, Jon Starr, Christopher M. U. Neale

Nebraska Department of Transportation: Research Reports

This report describes the development and implementation of an Unmanned Aircraft System Program at the Nebraska Department of Transportation (NDOT). The project involved the selection and purchase of appropriate UAS and imaging systems for NDOT, education and training for NDOT personnel with classroom and hands-on operation of UAS with the goal of obtaining proficiency and pilot licenses. In addition, the development of policy for the use of UAS within NDOT was accomplished as well as standard operating procedures (SOP) documentation and the development of example case studies of interest to NDOT using the purchased systems and technology.

Length Of Need And Minimum System Length For F-Shape Portable Concrete Barrier, Robert W. Bielenberg, Dylan T. Meyer, Ronald K. Faller, John D. Reid

Nebraska Department of Transportation: Research Reports

Portable concrete barrier (PCB) systems are often used to redirect errant vehicles through a combination of inertial resistance, lateral friction loads, and tensile loads developed from the mass and friction of the barrier segments. State departments of transportation (DOTs) and other end users may wish to utilize minimal length PCB installations to shield a hazard or work zone or limit the number of barriers required on the upstream and downstream ends to reduce overall system length. However, concerns with the performance of shorter PCB installations include increased lateral deflections and working widths and barrier pocketing. Additionally, no impact testing has …