Approach Guardrail Transition for Concrete Safety Shape Barriers

1998 ◽  
Vol 1647 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Ronald K. Faller ◽  
John D. Reid ◽  
John R. Rohde
Keyword(s):  
Performance Evaluation ◽  
Transition System ◽  
Safety Performance ◽  
Level 3 ◽  
Test Level

An approach guardrail transition for use with concrete safety shape barriers was developed and crash-tested. The transition was constructed with two nested thrie-beam rails, measuring 2.66 mm thick, and supported by nine W150 x 13.5 steel posts. Post spacings consisted of one at 292 mm, five at 476 mm, and three at 952 mm. Structural tube spacer blockouts were used in the transition system. The system successfully met the Test Level 3 requirements specified in NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features.

Approach Guardrail Transition for Single-Slope Concrete Barriers

1996 ◽  
Vol 1528 (1) ◽  
pp. 97-108 ◽  
Author(s):  
Ronald K. Faller ◽  
Ketil Soyland ◽  
Dean L. Sicking
Keyword(s):  
Performance Evaluation ◽  
Full Scale ◽  
Safety Performance ◽  
Vehicle Crash ◽  
Concrete Barriers ◽  
Level 3 ◽  
Crash Tests ◽  
Test Level

An approach guardrail transition for use with the single-slope concrete median barrier was developed and crash tested. The transition was constructed with 3.43-mm-thick (10-gauge) thrie-beam rail and was supported by nine W6 × 9 steel posts. Post spacings consisted of one at 292 mm (11.5 in.), five at 476 mm (1 ft 6.75 in.), and three at 952 mm (3 ft 1.5 in.). A structural tube spacer block (TS 7 × 4 × 3/16) was also developed for use with the thrie-beam rail. Two full-scale vehicle crash tests were performed, and the system was shown to meet the Test Level 3 requirements specified in NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features.

Guardrail Connection for Low-Fill Culverts

2003 ◽  
Vol 1851 (1) ◽  
pp. 105-116 ◽  
Author(s):  
Karla A. Polivka ◽  
Ronald K. Faller ◽  
John R. Rohde
Keyword(s):  
Computer Simulation ◽  
Performance Evaluation ◽  
Simulation Modeling ◽  
Research Study ◽  
Dynamic Testing ◽  
Safety Performance ◽  
Rigid Foundation ◽  
Level 3 ◽  
Crash Tests ◽  
Test Level

A W-beam guardrail system was developed for attachment to the top slab of a low-fill concrete culvert. The guardrail design was constructed with a single, 2.66-mm-thick W-beam rail totaling 53.34 m in length. Over the culvert, W150×13.5 steel posts 946 mm long spaced 952.5 mm on center supported the W-beam rail. The research study included dynamic testing with a bogie vehicle and steel posts attached to a rigid foundation, computer simulation modeling with BARRIER VII, and two full-scale vehicle crash tests. The crash tests used three-quarter-ton pickup trucks and were conducted in accordance with the Test Level 3 (TL-3) requirements specified in NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features. The first test was successfully conducted on the guardrail system with the back sides of the posts positioned 457 mm away from the front of the culvert’s headwall. The second test was unsuccessfully performed on the guardrail system with the back sides of the posts positioned 25 mm away from the front of the headwall. The safety performance of the W-beam guardrail system attached to the top of a low-fill concrete culvert was determined to be acceptable according to the TL-3 criteria found in NCHRP Report 350. Recommendations for the final placement of the guardrail system with respect to the culvert headwall are also made.

Development of a 34-in. Tall Thrie-Beam Guardrail Transition to Accommodate Future Roadway Overlays

2019 ◽  
Vol 2673 (2) ◽  
pp. 489-501
Author(s):  
Scott K. Rosenbaugh ◽  
Ronald K. Faller ◽  
Jennifer D. Schmidt ◽  
Robert W. Bielenberg
Keyword(s):  
Full Scale ◽  
Safety Performance ◽  
Performance Criteria ◽  
Concrete Barriers ◽  
Before And After ◽  
Level 3 ◽  
Crash Tests ◽  
Test Level

Roadway resurfacing and overlay projects effectively reduce the height of roadside barriers placed adjacent to the roadway, which can negatively affect their crashworthiness. More recently, bridge rails and concrete barriers have been installed with slightly increased heights to account for future overlays. However, adjacent guardrails and approach transitions have not yet been modified to account for overlays. The objective of this project was to develop an increased-height approach guardrail transition (AGT) to be crashworthy both before and after roadway overlays of up to 3 in. The 34-in. tall, thrie-beam transition detailed here was designed such that the system would be at its nominal 31-in. height following a 3-in. roadway overlay. Additionally, the upstream end of the AGT incorporated a symmetric W-to-thrie transition segment that would be replaced by an asymmetric transition segment after an overlay to keep the W-beam guardrail upstream from the transition at its nominal 31-in. height. The 34-in. tall AGT was connected to a modified version of the standardized buttress to mitigate the risk of vehicle snag below the rail. The barrier system was evaluated through two full-scale crash tests in accordance with Test Level 3 (TL-3) of AASHTO’s Manual for Assessing Safety Hardware (MASH) and satisfied all safety performance criteria. Thus, the 34-in. tall AGT with modified transition buttress was determined to be crashworthy to MASH TL-3 standards. Finally, implementation guidance was provided for the 34-in. tall AGT and its crashworthy variations.

NCHRP Report 350 Testing of W-Beam Slotted-Rail Terminal

1997 ◽  
Vol 1599 (1) ◽  
pp. 22-31 ◽  
Author(s):  
King K. Mak ◽  
Hayes E. Ross ◽  
Roger P. Bligh ◽  
Wanda L. Menges
Keyword(s):  
High Speed ◽  
Safety Performance ◽  
The Other ◽  
Federal Aid ◽  
Speed Limits ◽  
Crash Testing ◽  
National Highway ◽  
Level 3 ◽  
Test Level ◽  
Highway System

Two slotted-rail terminal (SRT) designs, one for use on roadways with speed limits of 72.4 km/hr (45 mi/hr) or less and the other for high-speed facilities, were previously developed and successfully crash-tested in accordance with guidelines set forth in NCHRP Report 230. Those SRT designs have been approved by FHWA for use on federal-aid projects. However, FHWA has since adopted NCHRP Report 350 as the official guidelines for safety performance evaluation of roadside features and required that all roadside features to be used on the National Highway System be crash-tested in accordance with the NCHRP Report 350 guidelines by 1998. It is therefore necessary to modify and retest the SRT designs in accordance with NCHRP Report 350 guidelines. The modified SRT design has successfully met the guidelines set forth in NCHRP Report 350 for Test Level 3 conditions, that is, 100-km/hr (62.2 mi/hr) and the results of the crash testing. The modified SRT design has been approved by FHWA for use on the national highway system.

Dynamic Evaluation and Implementation Guidelines for a Nonproprietary W-Beam Guardrail Trailing-End Terminal

2013 ◽  
Vol 2377 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Mario Mongiardini ◽  
Ronald K. Faller ◽  
John D. Reid ◽  
Dean L. Sicking
Keyword(s):  
Safety Performance ◽  
Crash Test ◽  
Impact Location ◽  
Close Proximity ◽  
Level 3 ◽  
Implementation Guidelines ◽  
Potential Risks ◽  
Departments Of Transportation ◽  
Crash Tests ◽  
Test Level

Most state departments of transportation use simple adaptations of crashworthy guardrail end terminals, which typically include breakaway posts and an anchor cable, for downstream anchorage systems. The guardrail safety performance for vehicular impacts occurring in close proximity to these simplified, downstream anchorage systems is not well known. Further, the length of need (LON) for the downstream end of these systems has yet to be adequately determined. This research project assessed the safety performance of the Midwest Guardrail System (MGS) for impacts occurring in close proximity to a nonproprietary, trailing-end guardrail terminal under the Test Level 3 conditions of the Manual for Assessing Safety Hardware. The two research objectives were to (a) determine the end of the LON for impacts with light pickup trucks and (b) investigate potential risks for a small passenger car to become unstable when striking the downstream end of the MGS anchored by the nonproprietary, trailing-end terminal. Numerical simulations were carried out to identify the most critical impact location for the 1100C small car and the end of the LON for the 2270P pickup truck. In full-scale crash tests, considerable snag of the 1100C vehicle occurred; however, occupant risk values and vehicle stability were within acceptable limits. The crash test with the 2270P pickup indicated that the end of the LON was located at the sixth post from the downstream-end post. Guidelines were proposed for installing the MGS to shield hazards in close proximity to the tested nonproprietary, trailing-end terminal.

scholarly journals Crashworthiness of Safe Fuels

1972 ◽  
Author(s):  
R. A. Rockow ◽  
L. M. Shaw
Keyword(s):  
Performance Evaluation ◽  
Fire Hazard ◽  
Full Scale ◽  
Safety Performance ◽  
Screening Tests ◽  
Aircraft Accidents ◽  
The Past ◽  
Relative Safety ◽  
Series Of Experiments ◽  
Aircraft Crash

Safety fuels such as emulsified and gelled fuels have been studied over the past several years as one means for reducing the post-crash fire hazard associated with aircraft accidents. However, through the work described herein, only recently has a quantitative evaluation been made to characterize the safety performance of these fuels. The safety performance evaluation program described in this paper includes an initial series of screening tests designed to obtain the characteristics of safe fuels in the aircraft crash environment. The authenticity of the screening tests relative to the full-scale crash environment was evaluated through a second series of experiments designed to simulate a full-scale aircraft crash environment. A crashworthiness evaluation criterion was established in terms of an “ignition susceptibility parameter” to quantitize the relative safety performance of different fuels. The conclusions of this research clearly show that significant savings in lives and equipment can be realized if safe fuels which perform within the non-hazardous envelope of the ignition susceptibility parameter are operationally incorporated in present-day aircraft.

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