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RE: pipe bollard for semi-truck

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We do bollards all the time for our mine clients.  Good luck at finding some information.  That isn't to say that they aren't out there.  Rather, we have developed some standard details for these.  Mostly, out details have been for large 400 ton haul trucks, but recently, I did one for a semi-truck.  What I used was some 6" pipe at 6 feet tall (you could use STD pipe for CMP, but it should be metal).  It was filled with reinforced concrete based on, I believe, the minimum steel requirments per ACI (I believe we used a couple two-tree #6 bars).  The vertical steel is hooked to the approach slab, so if it is struck, the thing just doesn't fall over.  It will still put up resistance even after struck. 
 
The thing is, you really can't estimate the load, so you have to put something up there.  The nice thing about the semi-trucks, is that these guys are pretty good at manuvering those things.  All they really need are some guides to make sure they all lined up good, and that is what these will provide.  Finally, you will want to make sure you paint the outside.  That's just about all you can do for this situation.
 
Bollards aren't meant to truly survive when it is struck.  If the vehicle is under good control, it wouldn't have been struck in the first place.  They are simply there to make sure that the driver hit it before they hit the structure.  You do that, and you have provided a bollard that meets its true purpose.
 
The haul trucks, however, was something completely different.  We had to come up with something that was large enough that a person essentially driving a 2 story house could see and avoid on all sides.  And we've been told that when a haul truck strikes a bollard, it is not even felt.  And these are some pretty large things.  Our latest was 24" diam. CMP by 8'-0" tall, reinf. w/ 10 #6 bars and #3 hoops at 8" o.c.  The longitudinal reinforcing was hooked into the footing.  That's right, these had their own footing, which I believe was 6 foot square and sat directly below the approach slab (which was 16 inches thick on it's own).  Why I remember this and not the other, I don't know.  Nevertheless, that is what we have done.
 
Dave Maynard, PE
Gillette, Wyoming
-----Original Message-----
From: Bruce Holcomb [mailto:bholcomb(--nospam--at)brpae.com]
Sent: Thursday, July 21, 2005 3:37 PM
To: seaint(--nospam--at)seaint.org
Subject: pipe bollard for semi-truck

We have been asked to design a pipe bollard for a semi-truck.  It is a typical situation where the truck will be moving slowly (maybe 5 mph max?) as it pulls into an interior loading dock.  We are looking at AASHTO, but aren’t finding anything specific for this situation (we have found info on highway guardrails in the AASHTO manual).  What force and applied at what height should we be designing for?  Does anybody have any recommended details?

 

 

Bruce D. Holcomb