concrete foundation beams for connecting individual foundations 1

[n3jc]

Im having some troubles with some expressions/translation here. I hope you will understand.

I have individual concrete founations under columns. There are concrete foundation beams which are connecting individual foundations together.
Above them there is a concrete slab (designed for wehicle load).

I dont know what to do about dimensions of concrete foundation beams here and may I connect concrete beam with slab or not. I have 3 options:

OPTION 1: I do not like the dimension (b/h = 30/130 cm) of concrete foundation beams (for connecting foundations). I think thats too much material going to waste.

OPTION 2: It his OK? As far as connecting foundation together, I think the is no problem. But I think there is aproblem because beams are not on bearing soil but on fill. In that case they do not help transfering loads to the bearing soil. What do you think?

OPTION 3: Slab is made on compacted gravel. There will be a wehicle driving on the slab so i dont think that is a good idea.

What do you guys suggest?

 

[Klitor]

a lot of it depends if the foundation system is "isolated footing + connecting beams" or "foundation beams"... ask your structural engineer.

O3 - depends of the soil quality, but its the way most industrial slabs are built...

 

[KootK]

Option two has some constructability advantages with respect to formwork etc. Option three will allow some underslab utilities to pass over the beams which may be important.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oldestguy]

A dumb question here. What is the structural function of these beams? Filling some space, like a wall? Transferring some slab load to the earth under these beams? Do these beams have any structural function in carrying column loads? Do they carry slab load to the footings? Is there a moment or shear diagram available for each? What is meant by the term "connecting". Any need because of seismic loads? Is there some need to account for or minimize effect of varying footing settlements?

 

[n3jc]

What is the structural function of these beams?

ANSWER: on outer beams there is a masonry wall. Inner beams also help minimazing local settlements and helping individual footings to stay in position (in case of earthquake). I believe if I connect them with the slab, they will also carry slab load to the footings?

I dont have much experience in this field.