shearwall footings 1

[calculor]

My client is considering to purchase a 9 storey apartment building. Our office was asked to review the record drawings. Everything appeared to be okay with the exception of the shearwall footings. The drawings indicate 15'x15'x3' pads at each end of the shearwall. I have never seen this before; is anybody familar with this type of foundation for a load bearing shearwall?

 

[UcfSE]

It sounds like the SEOR put a large footing under the shearwall chords. That is reasonable, if they are sized properly and consistent with the assumptions made.

 

[calculor]

I can understand the assumption that the shearwall would act like a deep beam spanning between the footings. However when checking overturning for the shearwall where would you assume the counterbalancing dl to occur?

 

[dik]

No difference between using large spread footings at the ends of the wall or using caissons. Same with lateral. Wall acts as a deep beam arching between between the footings.

 

[calculor]

Thanks guys. Just ran the numbers everyting appears to be okay. On another note has anybody used or heard of bubbledeck?

 

[dik]

Nope... but, you should be able to inform us... <G>

Dik

 

[Lutfi]

this web site will tell you all you need to know about it

http://www.bubbledeck.com/

Regards,
Lutfi

 

[dik]

Thanks, Lutfi... never seen this material before. Similar to the old Cowin pans that provide a waffle slab

Dik

 

[Lutfi]

Yes it is. It is more popular in Europe than the USA.

In Jordan, they use concrete joist systems that utilizes hollow, specially shaped blocks, to fit between the joists. The blocks act as forms for the joists. Of course they use shoring underneath. Those blocks remain in the floor or roof system and they provide, to some degree, an R value for the system. This works OK because labor is cheap over there.


Regards,
Lutfi