gatepost, flagpost, or bollard footing

[johndeng]

The design depth of the sonotube footing is about 10 feet. The load is the truck impact load.
Right now I am thinking the post should be embed into the sonotube, not on top since the anchorage is tough.
how far should the post be embedded?
does the sonotube require reinforcement? bollard would not require though.
do we need sleeve for the 6" post, and how big? with no shrink grout?

Thanks for any input!

 

[racookpe1978]

No one can address any of these different questions without a dimensioned elevation sketch of the proposed gate, ballard, and flagpole.
Hint: The flagpole will require very different analysis of wind loading than the gate and latch, which has significant gravity live loads and dead loads, and will very likely settle (sag) over time.

 

[jayrod12]

and just to be clear. Bollards don't stop trucks, they are merely a sacrificial piece intended to give warning before it drives into whatever else is important behind the bollard, or they are to act as a deterrent.

 

[johndeng]

This gate post is more like a truck bollard, heavier than regular bollard. Just want to get an idea.
regular bollard we only embed post without sleeve. While sign post are on top of sonotube.
But this is also gate post, need to be more straight.

 

[Teguci]

and just to be clear. Bollards don't stop trucks,...

Actually, bollards around federal buildings are designed to stop trucks. Especially trucks loaded with nitrogen and diesel fuel.

 

[jayrod12]

Agreed. but those are special cases. You aren't using just a steel tube in a 24" diameter concrete plug for those.

 

[johndeng]

What's the typical design for heavy truck bollards? Post embed in reinforced sonotube?

 

[jayrod12]

Is it intended on stopping the truck, or is it sacrificial? Stopping the truck needs a significantly more robust foundation to work.

 

[bridgebuster]

There are a number of Federal manuals available on line that deal with physical security.
Google
FM 3-19.30
FTA-TRI-MA-26-7085-05
UFC 4-022-02
UFC 4-022-03
MIL-HDBK-1013/1A

 

[johndeng]

I would say it's still sacrificial. Just imagine the full moment capacity of 6" standard steel pipe.

 

[thaidavid40]

You say sacrificial - I say, it depends. Watch this YouTube video of a truck hitting a retractable bollard. I'd say that it is the TRUCK that is sacrificial! And the bollard still works afterward!
Dave

https://www.youtube.com/watch?v=nP6SKDppwes

Thaidavid

 

[jayrod12]

I wonder how big the chunk of concrete is that bollard is embedded in.

 

[XR250]

That bollard is simply amazing. Kudos to whoever designed it

 

[Archie264]

Thaidavid40,

I believe that's an anti-ram bollard. A regular bollard won't behave that way.

 

[BUGGAR]

I declare B.S. on that truck/bollard test. The truck was "rigged" to absorb all the energy. Look closely. Where's the engine/drivetrain. Note also, the sand "ballast" and its placement to efficiently absorb the energy. Etc.

 

[SOL82]

There're two types of bollards :
A)non-security bollards which is not intended to to stop the vehicle but to give warning as described by jayrod12 , Those types of bollards are usually designed considering impact force of
26.7kn (passenger vehicles) as per IBC 2012 - 1607.8.3 .

B)Rated Security Bollards are designed to immobilize the vehicle while the bollard is still functioning after the impact which require a footing with massive dimensions and depth (Like 3.0m x 3.0m) for stability. The design of those bollards shall follow BSI PAS68 specifications.

Security bollards with its foundations are special ,designed/produced by specialized certified suppliers and shall be used only where specified in the project (Not everywhere).

 

[JAE]

SOL82 - agree with you - but there may be also a third type that is a warning - but only psychological....lots of shallow footing bollards (concrete filled pipes with 18" dia. conc. piers only 3-4 feet deep) that would "warn" someone visually to be careful and would "warn" someone if they hit them at slow speed.

We've done physical bollard projects where we used proprietary bollard designs that have been tested - they require special designs, testing, rebar, etc.:

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[Archie264]

Please note that in that last detail a "continuous" concrete footing is shown. From a quick glance or for people not familiar with steel reinforcing notation it might be mistaken assumed to be a drilled post hole type footing.

 

[JAE]

yes - correct -that is a grade beam not a pier.

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