Optimized Pre-Tensioning and Re-Tightening Approaches for Anchor Rods for Highway Signs, Luminaires, and Traffic Signals (SLTS)

Summary

Previous studies and field investigations have demonstrated that anchor rods at the base of structural posts for Highway Signs, Luminaires, and Traffic Signals (SLTS) are susceptible to relaxation. This results in loosening of base connections and premature failure of such structural supports. On the other hand, re-tightening of anchor rods 48 hours after the installation requires significant resources, manpower, and additional costs. This implementation project reviews past studies, systematically studies the pre-tensioning methods and re-tightening procedures through experimental testing to fill the knowledge gap, and proposes an optimized method for pre-tensioning and re-tightening of anchor rod connections to result in acceptable relaxation, while minimizing the resources for doing so, and minimizing chances of over-tightening. In the end, the proposed methodology will be implemented in two local structural supports for SLTS in the state of Minnesota to evaluate its effectiveness.