Steel Posts over Underground Structures (405160-12 T4541-AO)

For guardrail installations across low-fill culverts, small structures, or underground obstructions where proper post embedment cannot be achieved, either long span guardrail or steel post over underground structures are desirable. This study developed a steel post design anchored to a shallow moment slab for use on a typical strong post w-beam guardrail system. Full-scale pendulum tests were performed on the two footing designs. A comparison was made between the posts and concrete foundations tested for this project and standard W-beam guardrail line posts embedded in strong soil. Based on the results of this testing, the W6x8.5 steel post anchored to the 5 foot by 5 foot concrete footing is recommended for use in cases where a single post in a guardrail length of need interferes with an underground obstruction.