Vehicular barrier impact loads for trucks 3

[CQT3]

Hi, I am trying to design the foundation for a vehicle barrier. The barrier specs is that it can resist a 15,000 lb truck going 50 mph. I know ASCE specifies 6000 lbs for passenger car barriers but I doubt that is sufficient in this case. I looked at AASHTO and I couldn't find a number either. Does anyone know of an impact load I can reasonably use and which provision supports it? Certainly I can use energy equations to compute the impact force but without knowing how much the truck and barrier deforms during the crash, that isn't feasible.

Thanks.

 

[bridgebuster]

PI'm not following the question. what kind of barrier are you designing - solid concrete, corrugated guide rail, some thing else? You said your barrier specs state the barrier can resist 15k. Sound like the barrier can resist a force of 15 k at a certain angle, typically 15-degrees.

 

[JStephen]

Surely you need additional information from the barrier designer.
If you assume somewhat uniform deceleration over a specific time or distance interval, you can calculate a force, but that time or distance would have to come from the barrier supplier- it could be 6 inches or 6 feet. And a good bit of that would be distortion in the vehicle, so there's got to be some testing involved.

 

[DayRooster]

CQT3 - You are thinking correctly about it. I have gone down this rabbit hole before…

Start with this reference:

https://www.structuremag.org/wp-content/uploads/2014/08/C-StrucPractices-Iqbal-Sept101.pdf

Refer the last example within the pdf.

Also, when I get a moment I’m going to check some government and DOT references (I think Texas had the most testing information) to see if there is additional supplemental information.

Finally, is this a anti-terrorist barrier or just a simple vehicle crash barrier? If I remember correctly there are different parameters for each type of installation…

 

[robyengIT]

few more docs

 

[LittleInch]

We've been down this road many times.

If you click the search box at the top of the thread - not the top of the page - there is an option to search this forum.

Enter "vehicle barrier" and there are many posts on similar questions.

A 7 tonne truck doing 50 mph is some load though.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Tomfh]

The proprietary gear (barrier plus footing) is the way to go. It’s all tested for various energy scenarios. Trying to design from scratch via equivalent static load is the wrong way to go.

 

[robyengIT]

strain energy due to impact load

 

[JLNJ]

I agree that 6000 pounds might not quite be sufficient.


Maybe more like 2,000,000 pounds. Give or take.

 

[XR250]

I imagine a 16" diameter oak tree would suffice.