PTI Slab on Grade/Grade Beam!?! Movements?

[mohanvenn]

Friends:

Geotechs provide "ym" and "em" values to design Post-Tensioned Slab-on-grade/grade beam system. Structural Engineers take these values to determine the depth of beams and slab, no. to tendons, etc. etc....I.e design the system.

My question is Does the designed foundation structure is going to "tolerate" these movements (i.e., structural will not crack under those movements and allow the ym movements to happen)" or "inhibit (i.e., stop the ym movements for happening"?

I have my own thoughts, but I will sit on those. However, if we come to conclusion on this question. I have a follow up question.

Thanks
Mohan

 

[jdonville]

Mohanvenn,

I can only imagine that the structural element - of any type - should be designed to accomodate the expected movements. Naturally, the specific soil-structure interaction will influence the amount of deflection and the deflected shape of the structural element.

My understanding of a tensioned concrete element is that it puts the entire concrete cross-section into compression and eliminates the need for, at least, longitudinal steel reinforcement. It should not have any special properties to "prevent" defelctions.

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com