Design for out-of-plane forces

[joengineering]

Is the force Fp=.4*SDS*I*Wt for out of plane used to design the foundation as well, or is it only for the design of the wall and anchorage.

Thank You

JO

 

[KootK]

I think that it ought to apply to the foundation although I've never once seen the provision discussed in that context.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[DaveAtkins]

I think it is just for the masonry wall itself, not the foundation wall or roof diaphragm.

DaveAtkins

 

[joengineering]

Thank You guys. Hopefully it is not for the foundation.

 

[mike20793]

I interpret that provision as the wall and anything attached to it. There needs to be a sufficient load path.

 

[DaveAtkins]

For the design of the roof diaphragm and the rest of the seismic force resisting system, I use [SDS/(R/I)]*W. Depending on the R value, this can result in a larger force contribution from the masonry wall than 0.4*SDS*I*W.

DaveAtkins

 

[joengineering]

Daveatkins,

In my case I have a higher contribution from .4*SDS*I*W and almost by double. My question came from that, that great overturning makes my foundation size be much bigger.

JO

 

[joengineering]

I think I will design the foundation from the load path of the out of plane force in ASCE 7-10 12.11. First it is conservative, and second it make sense that you do not want to overturn your wall and that is based on the foundation.

JO

 

[Hokie93]

Is this a free-standing, cantilevered wall? Or is the wall braced at the top by a diaphragm? In my opinion the requirements of ASCE 7-10 12.11 are clearly intended to apply to structural walls laterally supported at the top and bottom. Having said that, you must follow the load path and the foundation should be designed for the load applied from the wall.