NCHRP Report 350 Evaluation of the T501 Bridge Rail with Soundwall (408460-F)

The Texas Department of Transportation (TxDOT) developed a new detail for a special type of T501 bridge railing with a soundwall attached atop the railing. The overall height of the bridge railing with a soundwall is 6 ft (1.8 m). The Houston District of TxDOT anticipates the new T501 railing with soundwall will be extensively implemented. The first installation site for this bridge railing/soundwall combination is on US Highway 59 from Mandell to Smith Street. In a cooperative research effort between TxDOT and the Florida Department of Transportation (FDOT), the height of the bridge railing with a soundwall was increased for FDOT and worst-case testing purposes to 8 ft (2.4 m). The standard T501 bridge railing has been crash tested previously and demonstrated acceptable performance for both structural adequacy and occupant risk. However, with the addition of the soundwall atop the barrier, TxDOT wanted to 1.) evaluate and confirm the structural adequacy of the soundwall portion of the railing when impacted by an errant vehicle and 2.) evaluate the effect the soundwall may have on the stability of the National Cooperative Highway Research Program (NCHRP) Report 350 4,405 lb (2000 kg) test vehicle and 17,616 lb (8000 kg) box van. The primary performance characteristic of interest in this project is the strength of the addition of the soundwall to the top of the T501 bridge railing. Therefore, researchers recommended omitting the small car test (4-10) and performing NCHRP Report 350 test designations 4-11 and 4-12. This report presents the details of the two NCHRP Report 350 tests (4-11 and 4-12). During the performance of both of these tests, the T501 bridge railing with the addition of the soundwall satisfied the performance guidelines presented in NCHRP Report 350.