Tracked crane loading 1

[struct19]

Hi
Is anybody familiar with "Tracked crane loading" on slab on grade. I am designing a parking slab on grade space for tracked crane. If you can help me to find the load distribuion of a tracked crane on slab on grade it will be helpful to me.

 

[kslee1000]

I think it is a gantry crane. Your project manager shall gather information on usage, aspects of operation, and expected lift loads, then get hold on the crane manufacture, which would provide assistance required.

 

[SlideRuleEra]

I assume what you mean is crawler crane, used in construction:

...if so, the distributed contact pressure with the slab will be very low while it is walking (in a straight line) or with no load (a few PSI, most likely).

However, the the "real" test is when it is lifting a heavy load. Then the majority of the load (machine dead weight + load being lifted) is concentrated in a small area of the track. This is more or less a line load and it will move if the crane swings (rotates about its vertical axis) to place the load at a new location.

If the crane turns while walking on the slab there can be quite a bit of abrasion to the concrete as the tracks tend to skid. The crane can also walk with the load suspended in mid-air, making the loading even more severe.

IMHO, a slab designed for this purpose should have two rebar mats. That makes the MINIMUM practical thickness 12 inches, or so.

Use statics to compute the worse case for loading, but consider these other factors, too.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[malaycobra]

I have loading software for many crane models. Let me know which crane you are using and the lift data. maybe I can help.

Also remember, due to the profile of the tracks on many crawler crane models (a lot of them "turn up" at the edges), the loadings are higher on concrete or steel than on a "soft" surface like compacted ground or even timber mats, as the track cannot sink a little bit into the surface, thus spreader the load over a greater area.

Even laying a few inches of plywood sheets can help the loadings to spread out better.

http://www.hliconsulting.com

Specialists in Heavy-Lift and Transport Planning