Cooling Tower Basin on Structural Steel

[J1D]

We’re in the process to design a cooling tower basin, which is comprised of c.i.p. concrete bottom slab and walls, and structural steel to support the basin (about 200ft x 60ft dimension). The basin is typically founded on ground with concrete piles, but because of the slope of the site and weak overburden soil, structural steel frame is chosen to level the slope and support the tower.

Here is my question: how to consider the basin concrete work together with support beams.

Since basin bottom slab and the perimeter walls are very rigid relative to the support beams (even use W24), under the load of water in the basin and other LL from the tower, more load will go to the steel columns directly. In the light of this consideration, should I use studs on the beams to form composite sections? Or save the beams, use the steel columns like the piles to support the basin directly. What do you think?

 

[SlideRuleEra]

J1D - When you use beams for any application, a certain amount of deflection is a fact of life. Since the mechanical equipment in cooling towers needs solid support, I suggest that you use the columns like piles.

http://www.SlideRuleEra.net

 

[JedClampett]

Since you're committed to steel framing and need to cast concrete over it, why wouldn't you make the members composite? For the cost of the studs, you've greatly increased the strength and will be able to use smaller steel members.

 

[J1D]

Thanks for the replies.

I like the base slab to be flat-plate to save the beams. If the beams and metal decks are still required even for forming purpose I'll design them as composite.