guardrail in shot rock

[jeremyk55]

Does anyone have a detail for placing guardrail in shot rock fill? I would like to place a section of pipe for each post before the fill is completed, and then secure the posts in the pipe with concrete. Is this commonly done with shot rock?

 

[PEinc]

Aren't you topping off the shot rock with some smoother material that would be better for riding on and for installing posts?

 

[jeremyk55]

I have 4" of #3 stone, 8" of DGA, and 8.5" of asphalt on the shot rock fill with has some dense grade material to fill the voids.

 

[PEinc]

Can you install less rock fill and more finer material along the guardrail line so that the posts will be in the finer material?

 

[MPENN]

Will this be installed in the USA? AASHTO design? Does the What type of guard rail system (strong post or weak post) are you proposing? What is the design speed for the road?

 

[jeremyk55]

Yes, this will be in the US (Kentucky). We are using a combination of AASHTO and KYTC specs. This is a private road (25 mph)going into a development in an inactive rock quarry. Because of the low speed/low volume traffic expectations, we are placing steel posts every 12'6" instead of every 6'3" as is typical on KYTC (Kentucky Transportation Cabinet) projects. I am not familiar with the strong post/weak post terminology, but I hope that answers the question.

 

[ACtrafficengr]

Some guiderail systems use heavy 6" I-beam posts. Others use 3" weak posts. I wouldn't be comfortable with heavy posts every 12'6". The beam will deflect more and a vehicel that hits the barrier is more likely to crash into the post. This often leads to injuries. Even though this is a private road, I'd consider staying with an approved guiderail system for liability reasons. Weak-post W-beam is less expensive and passed crash testing at 40 mph, but it may not be widely available in your area if KYTC doen't use it.

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"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail."

Wm. Phelps Eno, ca. 1928