Foundation Design for Dynamic Horizontal Impact

[confused859]

Perhaps there is an easy solution to my problem but I am stumped.

I want to determine the size of a shallow concrete foundation (ideally less than 5 feet deep and rectangular in shape) that is required for a set of bollards. My load would be a horizontal impact and moment with a very short duration that would occur at a very low frequency (once or less per year). I have only be able to find design information for static or dynamic vibration loads.

Any advice or guidance would be greatly appreciated.
confused859

 

[jdonville]

confused859,

You should rely on passive soil pressure to resist your impact load. I would use a Factor of Safety of 2.0 for the translation (sliding) resistance equations, since this load is expected to occur with some regularity.

Jeff