Sizing a bearing plate for point load on concrete slab
Sizing a bearing plate for point load on concrete slab
(OP)
We use air pallets to move heavy loads, but when we set the load down it causes a point load on the concrete slab. The desire is to dissipate the point load by providing a metal plate to set the point load down on that would spread the load out over the concrete. The problem is calculating the size of the plate to use. We are considering using 1/8 inch thick steel plates. The point load is about 6000 pounds. The concrete is older 3000 psi compressive strength, no rebar.
I searched for a similar question, found a few, but none that was exactly like this. I also look at the formulas in X Calcs, but couldn't find a match.
I searched for a similar question, found a few, but none that was exactly like this. I also look at the formulas in X Calcs, but couldn't find a match.






RE: Sizing a bearing plate for point load on concrete slab
6000 pounds total?
If the concrete is rated at 3000psi
then 1 inch square will withstand
3000psi. 2 inch square 6000psi etc.
You pick the safety factor.
RE: Sizing a bearing plate for point load on concrete slab
RE: Sizing a bearing plate for point load on concrete slab
I use the method in PCA's slab-on-grade design book.
DaveAtkins
RE: Sizing a bearing plate for point load on concrete slab
Steve
RE: Sizing a bearing plate for point load on concrete slab
RE: Sizing a bearing plate for point load on concrete slab
I would check this bearing plate as base plate per AISC Manual.
RE: Sizing a bearing plate for point load on concrete slab
RE: Sizing a bearing plate for point load on concrete slab
It is not sufficient to simply limit the stresses to normal stress levels, you need to limit the rigidity.
I would think that Timoshenko would cover this.
RE: Sizing a bearing plate for point load on concrete slab
Dik
RE: Sizing a bearing plate for point load on concrete slab
1. Size of pad you want
2. Whats holdidng the pad (centered in the pad)
t min = l x SQRT(2Pu/0.9 Fy.B.N)
l= the cantilevered lenght, for example if you have 3x3 column on 6x6 pad, then your cantilevered length is 1.5"
Pu=Ultimal axial load
B= Usually I use the symetrical column so the pad is symetric also. SO B = N = dimension of pad
Fy= steel strength
So for example I have 60kips on 3x3 column with 6x6 pad then my t min should be .373".
Let me know if I did this correctly guys!
RE: Sizing a bearing plate for point load on concrete slab