Safety Performance Evaluation of Weak-Post, W-Beam Guardrail Attached to Culvert
Allison Schneider, Scott Rosenbaugh, Ronald Faller, Dean Sicking, Karla Lechtenberg, John Reid
A new W-beam guardrail system for use on low-fill culverts was developed and evaluated. The system was adapted from the MGS bridge railing for attachment to the outside face of culvert headwalls. Four attachment concepts were developed and evaluated through dynamic component testing. Both lateral and longitudinal impacts were conducted on the design concepts while mounted to a simulated concrete culvert headwall. The resulting damage from each test was confined to post bending only. Although all four designs prevented damage to the socket assembly and culvert headwall, the top-mounted, single-anchor design and the side-mounted design were recommended for use based on ease of fabrication and installation. The new weak-post, W-beam guardrail system for attachment to low-fill culverts was designed with multiple advantages over current culvert treatments. The guardrail system is mounted to the outside face of the headwall, thereby minimizing intrusion over the culvert and maximizing the traversable roadway width. The barrier has an unrestricted system length and does not require a transition when attached to standard MGS. Additionally, the attachment configurations were designed utilizing epoxy anchors, enabling the system to be installed on new or existing culverts. Finally, implementation guidance was provided for new system installations.
Roadside Safety, W-beam, Guardrail, Culverts, Weak-Post, Non-Blocked, MASH, MGS, and Component Testing