Pedestal-Supported Concrete Slab Analysis 1

[MAFeng]

Hi,

Does anyone know of a method of determining the flexural capacity of a concrete slab supported by pedestals, subject to a point load? Such as in a floating concrete panel patio deck?

Think of a concrete slab section (say 24" x 16") simply-supported at each corner by pedestals (pedestals are not fastened to the slab, nor are they part of it, the slab just sits on them).

I would like to analyze this slab with a point load in the centre, or a load distributed over 1 sq.ft. in the centre.

I've searched through publications, textbooks, and Google to try and find an analysis method, but have so far come up empty-handed.

Any help at all would be greatly appreciated.

Thanks,

Matt

 

[hokie66]

If you are a student, homework questions are not permitted on the site.

 

[JAE]

Is the slab section 24" x 16"?
Or is the plan of the slab 24 ft. x 16 ft?

I'm confused.

 

[MAFeng]

I'm not a student, but I am an EIT. My intentions were not to have someone solve the problem for me, I was only looking for some help/guidance.

The slab is like a sidewalk slab (24" x 16", or any other size).

 

[CANPRO]

You could try and find your loading scenario in Roarks and then get your stress and deflections from there.

It sounds like Yield Line theory would be the way to do this by hand...I've seen this mentioned on here a few times before and have done some reading on it recently...there are a lot of publications out of Denmark on the subject. Just google 'yeild line theory' and you'll probably have more to read than you were hoping for.

 

[hokie66]

I am trying to interpret what you are doing, if it is a real world problem with such small dimensions. Sounds like you want to analyze a paver block supported on 4 corners...the kind used for a walking surface over a roof or plaza membrane. Is that correct?

 

[charliealphabravo]

I agree with Caneit that your best option is to find the configuration already solved in a reference.

Depending on the span and thickness of the panels, they will likely be governed by shear, rather than moment or deflection.

With a few checks you might find that applying the maximum load near one of the 4 supports results in the worst case shear effect. The potential failure surface should be pretty easy to find given the size and shape of the pedestals. You will need to decide whether the cracked or uncracked section is appropriate.

There may also be precast manufacturers who will provide the panels based on specified load and support condition.