Steel Pipe Bollards design

[Battleman]

Have a reviewer at a city that wants statement that a 4" steel pipe bollard, concrete filled, 36" imbed, 36" above ground will withstand 12,000 pounds at the 36" mark.
Im not an engineer of any kind, just trying to get a project permitted.
If it were a 4000lbs vehicle moving at 15mph would the bollard work. Deflection expected.
Thanks,
Mr, Uneducated.

 

[manstrom]

It won't work for the loadings that they describe. The 12k at 36" is very heavy. You fail by a factor of 2.

In the IBC world, the loading is 6k at 2'-3" for a vehicle impact in a garage. Are they making up the loading? Or is this an AASHTO requirement?

Sounds like you need to hire an engineer.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[bridgebuster]

What's the purpose of the bollards for your application? Is it to protect a building column from a vehicular collision- I've seen the 12K requirement once before and in that situation it was impossible to achieve - is it a security provision to stop a vehicle, or is it just something intended to warn a driver from backing up into a loading dock?

The DOD uses 4000LB load at 30 mph for design of bollards that are intended for security. This publication from the FTA, FTA-TRI-MA-26-7085-05/DOT-VNTSC-FTA-05-02, has details of bollards used for physical security.

 

[Battleman]

It is for a fueling application. Bollards at the fuel dispensers.
Thanks

 

[bridgebuster]

Attached is a detail for bollards that were installed at truck loading areas in a wastewater treatment plant - I bet they probably look just like yours. If you need something more robust look at the FTA manual.

Perhaps your reviewer doesn't realize that the 12k requirement shouldn't apply in this case.

 

[LittleInch]

Your reviewer has no grasp of energy and mechanics and is requiring something that is not practical from one 4" post.

12,000lbs force is nigh on 6 tons - He needs to justify where that requirement comes from first otherwise you will spend time and money trying to meet a requirement from an individual who may have seen it somewhere but for something completely different.

These sorts of bollards are to prevent really low speed movements, not 15 mph.

I pity you trying to talk sense to your reviewer but give it a go and if it gets thrown back then you need to try and find his superior and talk some sense.

Good luck and let u know how it goes....



My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[BUGGAR]

What City is this?