Temporary Plate to Hold Anchor weight

[AngrySubContractor]

Hello,

I need to calculate the minimum thickness of this plate that will temporarily hold a max weight of 4,185 Lbs. The plate will rest on ground level and the weight will be at the center of the hole. Please see attached.

We have anchors that will go into a drilled hole, this anchor is very long (150') and has to be installed in sections. We usually connect the sections on the ground and then lift the entire assembly into the hole, this anchors being so long it has to be temporarily suspended, so we can connect while suspended in the hole. The idea is to use a flat plate that can go over the hole and "fork" the anchor by holding a lock nut/anchor system. I need to make sure whatever we order is thick enough to hold a maximum 4,185lbs anchor weight. We usually are able to get a shop to plasma cut A36 material. Thanks in advance for any help.

 

[Eng16080]

Since there's a notch cut through more than half the plate width, I would conservatively analyze it as though it were two separate plates (as though the notch went all the way through). I would design a plate washer to transfer the load from the nut to each of the separate (half) plates. From there, I would design each (half plate) to support half the load over an effective width equal to the contact area between it and the washer. Likewise the washer should be designed for loading over this area. This approach is conservative but probably reasonable considering the relatively small load. I suppose you could also perform a finite element analysis but I'd probably avoid that. I'm guessing the plate deflection is of little concern, but if that's not the case, be sure to check that as well.