Engineering Commons^™

Investigation And Modification Of Single-Post Aluminum Sign Supports For Mash Crashworthiness, Rodrigo Quintero

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Traffic signs are used to display information to drivers and are one of the most commonly encountered roadside structures. Although they are a vital traffic control device, signs can pose a significant safety risk to errant drivers due to their extensive placement and proximity to the roadway. Therefore, traffic signs and their supports must be designed with crashworthiness in mind to reduce the likelihood of injury in the event of a vehicle impact. Prior to 2009, these systems were evaluated using the crash testing criteria found in the National Cooperative Highway Research Program (NCHRP) Report No. 350 [1]. Currently, they …

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 …

Development Of A Mash Tl-4 Steel, Side-Mounted, Beam-And-Post, Bridge Rail, Oscar Pena

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

A new steel, side-mounted, beam-and-post, bridge rail was designed, crash-tested, and evaluated according to safety performance guidelines included in the American Association of State Highway and Transportation Officials Manual for Assessing Safety Hardware (MASH) for Test Level 4 (TL-4). The new bridge rail system was designed to be compatible to multiple concrete bridge decks utilized by the States of Illinois and Ohio. Bridge rail configurations were designed and optimized based on weight per foot, constructability, and safety. Post-to-rail and rail-to-rail connections were designed for the new bridge rail. Several concepts for these connections were configured, and after discussion with representatives …

Mash Test Nos. 3-11 And 3-10 On A Non-Proprietary Cable Median Barrier, Justine E. Kohtz, Robert W. Bielenberg, Scott K. Rosenbaugh, Ronald K. Faller, Karla A. Lechtenberg, John D. Reid

Nebraska Department of Transportation: Research Reports

The Midwest States Pooled Fund has been developing a new non-proprietary cable median barrier. This system incorporates four evenly spaced cables, Midwest Weak Posts spaced at 8 to 16 ft (2.4 to 4.9 m) intervals, and a bolted, tabbed bracket to attach the cables to each post. Full-scale crash testing was needed to evaluate the barrier’s safety performance. According to the Manual for Assessing Safety Hardware (MASH) updated/proposed testing matrix for cable barriers installed within a 6H:1V or median ditch, a series of eight full-scale tests are required to evaluate the safety performance of a system. A ninth test is …

Midwest Guardrail System (Mgs) With An Omitted Post, Jessica L. Lingenfelter, Scott Rosenbaugh, Robert W. Bielenberg, Karla A. Lechtenberg, Ronald K. Faller, John D. Reid

Nebraska Department of Transportation: Research Reports

The objective of this research study was to evaluate the MGS (31” tall W-beam guardrail) with an omitted post according to the safety performance criteria provided in MASH. A single full-scale crash test was conducted with the 2270P pickup truck in accordance with MASH test no. 3-11. The small car test, test no. 3-10, was deemed unnecessary as the pickup truck test would result in higher rail loads, a greater propensity for rail rupture, and a greater risk of failure. The test installation utilized standard 6-ft (1.8-m) long steel guardrail posts with 12-in. (305-mm) deep blockouts. A single post was …

Performance Characteristics Of Posts Embedded In Soil, Brandt M. Humphrey, Karla A. Lechtenberg, John D. Reid, Ronald K. Faller, James C. Holloway

Nebraska Department of Transportation: Research Reports

The primary objective of this research study was to determine the post-soil impact reaction of W6x8.5 (W150x12.6) steel posts and 6-in. x 8-in. (152-mm x 203-mm) Southern Yellow Pine (SYP) posts, specifically along the weak axis. Five bogie tests were conducted on W6x8.5 (W150x12.6) A992 steel posts with a length of 72 in. with embedment depths ranging between of 24 and 40 in. (610 and 1,016 mm). Four bogies tests were conducted on 6-in. x 8-in. (152 mm x 203 mm) SYP posts embedded at depths ranging between 30 and 40 in. (735 and 1,016 mm). The target impact conditions …

Cable-To-Post Attachments For Use In Non-Proprietary High-Tension Cable Median Barrier – Phase Ii, Scott K. Rosenbaugh, Robert W. Bielenberg, Brandt M. Humphrey, Ronald K. Faller, John D. Reid, Karla A. Lechtenberg

Nebraska Department of Transportation: Research Reports

The research objectives reported herein were based on further development of cable-to-post attachment hardware for use in the non-proprietary high-tension cable barrier system. Specifically, this project aimed to develop and evaluate alternative attachment designs for the bolted, tabbed bracket and evaluate the use of a larger diameter, keeper rod for use in the top cable attachment. From a group of over 25 alternative attachment concepts, two tabbed bracket designs were selected for evaluation through dynamic component testing: 1) the lateral shear plate attachment and 2) the drop-in shear plate attachment. The drop-in shear plate concept did not perform as intended, …

Design Of An Improved Post For Use In A Non-Proprietary High-Tension Cable Median Barrier, Robert W. Bielenberg, Ronald K. Faller, Karla A. Lechtenberg, Tyler L. Schmidt, Scott K. Rosenbaugh, John D. Reid, Dean L. Sicking

Nebraska Department of Transportation: Research Reports

The objective of this research study was to develop a revised post section for the non-proprietary high-tension cable median barrier that improved the safety and function of the post by lowering strong-axis forces. A total of twenty dynamic component tests were performed, along with one cable pull test – ten tests with the 7-gauge C-section post, eight with the 10-gauge C-Section posts, and three with the Midwest Weak Post (MWP). The tests were conducted with the posts installed in either a compacted, crushed limestone soil or a rigid sleeve in order to determine the force vs. deflection and energy vs. …

Conceptual Development Of An Impact-Attenuation System For Intersecting Roadways, Joseph G. Putjenter

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Longitudinal barriers are commonly used to shield hazards, including stiff bridge rail ends and slopes. In some locations, a secondary roadway intersects the primary roadway within the guardrail’s length-of-need (LON). Some intersections have as little as 15 ft (4.6 m) between the intersection and beginning of the bridge railing, which require short-radius guardrail systems. No short-radius systems have been tested and approved to current impact safety standards for shielding hazards with these conditions.

Site conditions provided by the Nebraska Department of Roads were used to determine the constraints for a new safety treatment for intersecting roadways and include intersection radii, …

Increased Span Length For The Mgs Long-Span Guardrail System, Nicholas A. Weiland

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Long-span guardrail systems have been recognized as an effective means of shielding low-fill culverts while minimizing construction efforts and limiting culvert damage and repair. The current MGS long-span design provided the capability to span unsupported lengths up to 25 ft (7.6 m) without the use of nested guardrail. The excellent performance of the MGS long-span system in full-scale crash tests suggested that longer span lengths may be possible with the current design.

A detailed analysis of the MGS long-span guardrail system was performed using the finite element software program LS-DYNA^®. It was shown that the MGS long-span design …

Development Of A Mash Tl-3 Transition Between Guardrail And Portable Concrete Barriers, David A. Gutierrez

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Often, road construction causes the need to create a work zone. In these scenarios, portable concrete barriers (PCBs) are typically installed to shield workers and equipment from errant vehicles as well as prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed in order to place the portable concrete barrier system. The focus of this research study was to develop a proper stiffness transition between W-beam guardrail and portable concrete barrier systems. This research effort was accomplished through development and refinement of design …

Safety Investigation And Guidance For Work-Zone Devices In Freight Transportation Systems Subjected To Passenger Car And Truck Impacts With New Crash Standards, Ronald K. Faller Ph.D., P.E., Dean L. Sicking Ph.D., P.E., Karla A. Lechtenberg M.S.C.E., E.I.T., James C. Holloway M.S.C.E., E.I.T., Jennifer D. Schmidt

Mid-America Transportation Center: Final Reports and Technical Briefs

Crashworthy, work-zone, portable sign support systems accepted under NCHRP Report No. 350 were analyzed to predict their safety peformance according to the TL-3 MASH evaluation criteria. An analysis was conducted to determine which hardware parameters of sign support systems would likely contribute to the safety performance with MASH. The acuracy of the method was evaluated through full-scale crash testing. Four full-scale crash tests were conducted with a pickup truck. Two tall-mounted, sign support systems with aluminum sign panels failed the MASH criteria due to windshield penetration. One low-mounted system with a vinyl, roll-up sign panel failed the MASH criteria due …