Reshoring deck for forklift load 2

[Dzastr]

Concrete sub wants to reshore garage deck down to mat slab with forklift loading in mind. EOR will not allow forklift to be driven on garage deck without reshores because garage deck was only designed for a 6,000lbs automobile load, forklift weights 8,000lbs and will have a 2,000lbs load.

Forklift Load = 10,000lbs
Forklift Footprint = 20sf

do i need to reshore for a 500psf load, or can I assume the deck spreads the weight out to other shores? keeping in mind that I will be reshoring down to mat slab, meaning there will be no deflection in the garage deck. I have an 8" thick pt deck. what other information about the deck would be usefull in figuring this out?

is there a good place to learn more about shoring and reshoring other than ACI 347 and ACI guide to shoring and reshoring?

 

[Dzastr]

Also, on the shear, Shouldn't it just be

(7'*0.050kpf)/2 = 0.175k

I can't wrap my head around multiplying by the span.

 

[Archie264]

Dzastr,

RHTPE was calculating the approximate design capacity of a 7' section of the slab to compare it to the applied load, which he demonstrated would act over roughly that width of slab (i.e. 7'). I believe your equation refers to the applied load.

That said, perhaps I should let RHTPE speak for himself.

 

[Archie264]

Regarding shear, it was assumed that the slab was designed for 50 psf (note: psf, not p per ft), therefore w = .050ksf x 7' = .350k/'. Shear is then (.350k/' * 22')/2 = 3.85k

 

[Dzastr]

Ah, yes I see now. I've been picturing this forklift driving perpendicular to the span. Makes sense now.

 

[RHTPE]

Archie264 is correct. Maximum shear on the 7' wide slab strip occurs when the wheels are near the supporting beam. Maximum moment occurs when the wheels are at midspan of the slab. The 7' slab width is a variable and will depend on the forklift used, plus whatever contributory width each side is deemed appropriate.

One of my former employers typically used forklifts to lower beam forms and deck tables for multi-story parking garage construction. The forklift chosen was usually the lightest one having the required lift capacity. To the best of my knowledge there were no adverse effects on the completed slabs.

As with any load applied to a newly completed slab, the analysis of the reshoring can be a challenge, especially so with heavy moving loads.


Ralph
Structures Consulting
Northeast USA

 

[RHTPE]

Dzastr

Ah, yes I see now. I've been picturing this forklift driving perpendicular to the span. Makes sense now.

Keep in mind that the forklift could be in any orientation with respect to the slab span. If it's being used to bring form assemblies/panels to an outrigger platform, then the field might do a lot of jockeying around to get the load positioned correctly for a crane pick.


Ralph
Structures Consulting
Northeast USA