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I recently received a question (copied below) on potential pinning of portable concrete barrier placed on a bridge deck. I’ve done some looking but didn’t come up with guidance for this situation. Any guidance you can provide is greatly appreciated. If pinning the barrier is necessary in this case, are there multiple methods or a recommended method to use? I’ve attached a PDF of our standard plate for Movable F Shape Concrete Barriers.

The Sioux Falls area is trying to decide whether concrete barriers require pinning to a bridge deck.

These barriers will be placed on the edge of a new bridge deck constructed, about 1 foot away from the edge. The barriers will be pinned together, and the posted speed limit would be 25 mph. The impact angle is unknown, but this is an interchange so the angle may be 35 degrees at worst case scenario.

Basically, we need temporary barriers that will have zero deflection upon impact given they will be 1 foot away from the edge. To achieve this, is pinning them to the bridge deck required?

Thank you,

A couple of comments on the installation noted below.

Placement of PCBs adjacent to a deck edge represents a critical installation due to the potential consequences if the barriers deflect beyond the limited space available. We have done some preliminary work looking at vehicle impact severity versus barrier deflection for the F-shape PCB you use. See the chart below.

For your installation with a speed of 25 mph and a potential angle of 35 degrees, the IS value is around 34 kip-ft. This would result in a predicted barrier deflection of more than 30”. This level of deflection would likely move the barrier too much to be retained on the deck given your 1’ offset.

In that case, we would recommend pinning of the barrier to the deck.

Let me know if you have any questions.