Crash Tests of R4 Retrofit and Open Parapet Bridge Rails

摘要

Full-scale crash testing was performed on two different bridge rail systems. Thefirst was a proposed thrie-beam retrofit for the Michigan Department of Transportation's (MDOT) R4 railing system. The second rail was MDOT's open parapet rail system. Although neither system is currently specified, there are 148,000 ft of R4 bridge railing, and 281,000 ft of open parapet railing in use on Michigan's trunkline system. All testing followed the requirements set out in NCHRP 230 and the AASHTO Guideline Specifications for Bridge Railings. Both systems were tested with an 1,800-lb car, a 5,400-lb pickup truck, and an 18,000-lb straight truck. The success of these tests on the proposed R4 retrofit bridge rail indicate that it meets all of the required criteria of the AASHTO Guide Specifications for Bridge Railings, performance level 2, as well as all pertinent criteria of NCHRP 230. On the open parapet rail system, the 5,400-lb pickup truck test was a failure due to an intrusion into the passenger compartment. The 18,000-lb truck test was a failure due to the detachment of the aluminum tube rail and the potential for that rail to create a hazard to other traffic. The open parapet rail was modified by removing the aluminum tube rail, and retested with a 5,400-lb pickup truck. The test was a failure since the integrity of the passenger compartment was not maintained.