Development of a TL-3 deep beam tubular backup bridge rail : executive summary report.

713021806Executive summary report.PDFTech ReportFHWA/OH-2010/18134394Bridge railingsDesignOhioOhio. Dept. of TransportationAbu-Odeh, Akram Y.Williams, William F.Buth, C. EugeneKim, Kang-MiTexas Transportation InstituteNTL-HIGHWAY/ROAD TRANSPORTATION-Bridges and StructuresNTL-HIGHWAY/ROAD TRANSPORTATION-DesignUS Transportation CollectionOhio Department of Transportation (ODOT)\ue2\u20ac\u2122s Office of Structural Engineering has a need to evaluate and, if necessary, improve an existing bridge rail design with a simple retrofitting procedure to meet current or proposed crash testing standards. This bridge rail is the ODOT deep beam bridge guardrail that has been accepted to National Corporate Highway Research Program (NCHRP) Report 350 Test Level 2 (TL-2). A TL-2 condition involves an 1808 lb (820 kg) passenger car and a 4400 lb (2000 kg) pickup truck impacting the bridge rail at a speed of 43.5 mph (70 km/h). The impact angles for the passenger car (test designation 2-10) and pickup truck (test designation 2-11) are 20 and 25 degrees respectively. However, this bridge rail cannot be constructed (or more importantly, cannot remain) in locations where a TL-3 bridge rail is required. The TL-3 conditions involve an 1808 lb (820 kg) passenger car and a 4400 lb (2000 kg) pickup truck impacting the bridge rail at a speed of 62 mph (100 km/h). The impact angles for the passenger car (test designation 3-10) and pickup truck (test designation 3-11) are 20 degrees and 25 degrees, respectively.The current policy for bridge railing requires upgrading non-conforming railing systems to the TL-3 acceptance level during certain types of structural rehabilitations. The costs associated with such railing upgrades will often exceed the allotted budget for the project resulting in rehabilitations that are not performed and non-conforming railing systems left in service. Hence, there is a need for a cost effective retrofit upgrade to such railing system