A Modified Foundation for Breakaway Cable Terminals (Superseded)

This digest recommends a modification to the foundation detail for the timber post version of the breakaway cable terminals (BCT), and reemphasizes a feature of the BCT which has been shown by accident experience to be crucial to proper performance. Questions which this research study attempted to answer are; how can the cost of the concrete footings for the breakaway posts be reduced; how can removal of broken timber posts from the concrete footings be facilitated; how can the guardrail BCT be adapted for use where site conditions do not allow the 4-ft glove specified in the recommended design? The foundation detail developed by the Illinois Department of Transportation is described. This project included a limited study of the anchor strenghth of this detail. Dynamic tests were conducted and detail was modified to produce acceptable test results. The test procedures and results are summarized. The installation of the BCT is illustrated with diagrams and alternative foundation systems are described.