Need to confirm bollard design for vehicle impact 3

[BrianBoen]

I have specified a schedule 80 steel bollard with an 8" diameter. The bollard is 3' above ground and 3' below ground with a 42" deep concrete encasement with minimum 4" cover on all sides of the steel pipe.

The client would like me to confirm that the bollard will withstand the impact of a 4000 pound vehicle at 30 mph. How do I convert the 4k pound @ 30 mph impact into a point load or factored load of some sort?

I have the allowable bearing pressure and steel information. It seems like I have everything that I need except for a load or force that I can use. I know
KE = 1/2 x m x v^2 and
F = m x a
but I don't have an acceleration and kinetic energy doesn't really help does it. Can anyone help?

 

[MaddEngineer]

kslee1000:

Scenario 2 seems to be inline with what I'm thinking in terms of behavior, but its been a long time since I took a dynamics class so I'm a few pages behind. But I think you stated it eloquently, but, this is a great exercise for something as you stated will be coming up more and more often.