Mid-America Transportation Center
Mid-America Transportation Center: Final Reports and Technical Briefs
Date of this Version
2015
Document Type
Article
Citation
MwRSF Research Report No. TRP-03-313-15
Abstract
The research objectives reported herein were based on further development of cable-to-post attachment hardware for use in the non-proprietary high-tension cable barrier system. Specifically, this project aimed to develop and evaluate alternative attachment designs for the bolted, tabbed bracket and evaluate the use of a larger diameter, keeper rod for use in the top cable attachment.
From a group of over 25 alternative attachment concepts, two tabbed bracket designs were selected for evaluation through dynamic component testing: 1) the lateral shear plate attachment and 2) the drop-in shear plate attachment. The drop-in shear plate concept did not perform as intended, as the vertical release load was too high and the lateral release loads were too low. Alternatively, the lateral shear plate design provided vertical and lateral release loads very similar to the original bolted, tabbed bracket V10. However, concerns were raised over the lack of rigidity in the attachment and the ease of installations of the shear plate. Thus, it was recommended that the lateral shear plate design be modified and reevaluated prior to use in the full-scale system.
Dynamic bogie or component testing of the 3/16-in. (4.8-mm) diameter brass keeper rod provided a quick cable release similar to the previous design. The increased strength of the rod also showed promise in distributing impact loads more uniformly to adjacent posts and helping reduce system deflections. Thus, the 3/16-in. (4.8-mm) diameter brass rod was recommended for use in the new high-tension cable barrier system.