Crash-Tested Bridge Railings and Transitions for Wood Bridges – Phase IIa
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ABSTRACT
In this study, an updated design configuration for a Manual for Assessing Safety Hardware (MASH 2016) Test Level 4 (TL-4) crashworthy glulam timber rail with a curb bridge railing system was developed. Many similar systems were developed in the past to meet previous impact safety criteria, but an updated design was necessary to meet current MASH impact safety criteria. A thorough review of similar systems developed under previous crash testing standards was performed during the development of the bridge railing system. The most recent iteration of this type of system, developed by MwRSF in the 1990s under NCHRP Report No. 350, served as an initial basis for the updated system. In order to create a new system deemed acceptable under MASH criteria, simulation using BARRIER VII software was performed with models originally developed for the NCHRP Report No. 350 system. The original models were examined piece by piece and general updates were made to utilize the increased capacities of BARRIER VII. After a series of modifications to the bridge railing system model, including increasing the size and height of multiple components, the simulation effort demonstrated that the modified TL-4 bridge railing was acceptable under MASH criteria. Additional research on connection details and timber deck strengths, the development of an approach guardrail transition system, and component and full-scale testing programs are yet to be performed to complete Phase IIa of this project.
KEYWORDS
Highway Safety, Crash Test, Roadside Safety Appurtenances, Compliance Test, Bridge Railings, Timber Bridges, Timber Railings, Wood Railings