Distributing Weight on Ground with Plate

[CraneEng87]

Hello,

I need to lay a temporary crane rail down in an asphalt parking lot and plan to distribute the load using plate. I am trying to determine the usable plate width and needed thickness. I need to keep the stress into the asphalt below 3000 psf.

Anyone know of a good reference for this?

Some additional information:
Rail will be 60 lb crane rail
The rail width is only about 4.25"
I was planning on assessing an 8' long section.
I plan to lay down 4' x 8' plate with the crane rail running down the middle parallel with the 8' edge.
I assume the entire 4' width cannot be accounted for in distributing the weight.

Any help would be appreciated.

 

[BMart006]

What is the wheel load/spacing to be used?
Two ideas here: 1. Use AISC Part 14 (in the 14th edition) to determine the minimum thickness for a plate that 4' wide (though this may be overly conservative since you probably don't need the entire plate at 3000psf. 2. Look up Newmark's Method. It is an iterative method that can be used to determine ground loading based on a predefined moment of inertia (predefined plate thickness). You may need to do three or four iterations but you should be able to see some level of convergence after that.