6 storey building

[calculor]

I have a six storey bldg., ICF exterior walls and two way slabs with interior columns. The architect has removed the wall at the first floor level. I am proposing columns along the section where the wall has been removed. The columns will extend for the full six storeys with the ICF wall being supported at each level on the 10"slab. I am having a problem conceptualizing whether load will be transferred thru the ICF wall as well as the columns. I prefer not to use a spandrel beam. Anybody come across a situation similar to this?

 

[kslee1000]

Can you provide more info on the "ICF" wall? Is it a curtain wall or bearing wall? If it is the former, how it was supported before?

 

[AUCE98]

ICF, is that insulated concrete form walls? I would suspect that the force for the upper floors is transfered to the walls , unless you are structurally isolating the walls from the floor, to the column at the first floor. The wall would act as a deep beam of sorts.

Regards,

AUCE98

 

[calculor]

That's what I suspect the wall acting like a deep beam for the six stories. Think I will get the contractor to leave a 1" gap between the u/s of the slab and the top of the wall to prevent load from being transferred to the wall.

 

[dik]

Why not use the ICF walls for support and deal with the columns at the lower level?

Dik

 

[AUCE98]

I would agree with Dik, easier detailing and construction.

AUCE98

 

[calculor]

I guess I'm just having a problem conceptualizing. I competely understand using the icf wall as a deep beam and pickup the support at the first floor. However if I have openings for windows and doors within the wall would the beam concept still be valid?

 

[concretemasonry]

Dik has a great approach.

They do it every day on 15 story loadbearing buildings with masonry where open areas are needed on the first floor. Just follow the flow of the loads down and around openings.

The wall is still a structural element carrying the loads above the first two floors, where you must distribute the loads around the opening. Take advantage of the lateral load transfer of the walls, since columns are not always efficient or cheap.

The economics for this approach since the repetition on the upper floors may offest the costs of redistributing the loads are the "architecturally pleasing" opening. You nay have some minor changes in reinforcement in the upper levels (maybe only 2dn and 3rd floors)

Dick

 

[AUCE98]

To act as a deep beam you would need to have a an unobstructed "bottom chord", so if you have doors, it may not act as a deep beam without a spandrel beam. To get around this problem you could place a spanderal beam along the length of the wall, where it would act as the bottom chord. Also, you would need to reinforce around the openings based on a strut and tie model, and ensure that the gravity forces can get around the doors and windows.

 

[dik]

Pretend they are concrete walls and design accordingly... of a bit of a concern, when you strip a concrete wall you see concrete... with ICF, you see foam and generally ICF walls use higher slumps...

Dik

 

[csd72]

Facade panels are exposed to the full effect of diurnal temperature variations, the connections are therefore designed to give when the panel shrinks and swells.

I would not rely on the panels for support. I would design the columns to take the whole load, but allow for the fact that the panels 'might' take the load.

Speak to the manufacturer to see if there is any gap left at each floor to allow for expansion. I would be surprised if there wasnt as 6 floors of panels installed in winter will be larger in the heat of summer.