Development of a Socketed Foundation for Cable Barrier Posts-Phase I
Ryan Terpsma, Ling Zhu, John Rohde, Benjamin Dickey, Scott Rosenbaugh, Ronald Faller
Four socketed foundation designs were evaluated for use as a new reusable base for high-tension, cable barrier systems. Each foundation was a reinforced concrete cylindrical shape. The top of the foundation had an open steel tube to accept the post during installation. The four foundation designs were installed in sand and subjected to dynamic component testing in order to simulate a weak/saturated soil and evaluate maximum displacements during impact events. An S4x7.7 (S102x11.5) post was selected for each test assembly after a review of the current FHWA-accepted, high-tension cable barrier systems revealed the section to be the strongest and most critical post. Both the 24 in. (610 mm) and 36 in. (914 mm) deep foundations rotated through the soil and were deemed too shallow to prevent excessive deformations. The other two assemblies, both 60 in. (1,524 mm) deep, fractured during the impact event. As a result, the 60 in. (1,524 mm) deep configurations were deemed too weak to sustain the full load capacity of the S4x7.7 (S102x11.5) post. Further, the displacement for the 60 in. (1,524 mm) deep foundations could not be determined due to premature fracture. Therefore, none of the four socketed foundation configurations was found to be acceptable and further development and testing was recommended.
Highway Safety, Crash Test, Roadside Appurtenances, S4x7.7, High-Tension, Cable, Guardrail, Post Base, Concrete Footing, Socketed Posts
Other files to download