Nebraska LTAP



Ronald K. Faller

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MIDWEST ROADSIDE SAFETY FACILITY, Nebraska Transportation Center, University of Nebraska-Lincoln

Midwest States Regional Pooled Fund Research Program Fiscal Years 2008-2009 (Years 19 and 20) Research Project Number TPF-5(091) Supplement #2 and TPF-5(193) Supplement #19 NDOR Sponsoring Agency Code RPFP-09-02 and RPFP-10-CABLE-1


A socketed foundation was designed and evaluated for use with the Midwest Weak Post (MWP), Version 1. Dynamic component testing was conducted on five different design configurations with varying embedment depths, steel reinforcement, and soil conditions. The low strength of the MWPs limited the force transferred into the foundations and prevented damage in the form of concrete cracking or fracture. Additionally, the lateral movements of the socketed foundations were all within the 1-in. (25-mm) limit established to ensure reuse of the foundations without resetting. The selected design consisted of a 12-in. (305-mm) diameter concrete shaft reinforced with four vertical bars and transverse hoop steel spaced at 6½ in. (165 mm) on center. A 4-in. x 3-in. x ¼-in. (102-mm x 76-mm x 6-mm) steel tube socket was placed in the middle of the shaft. Finally, guidelines were given for the length, or embedment depth, of the foundation based on surrounding soil conditions and risk of frost heave.