Concrete Tilt Up Wall Panel

[CowboyBill74]

Hello all-

I am unfamiliar designing tilt up concrete wall panels and i have been given the task to preliminarily design a 70 foot high wall panel in the proximity of Los Angeles, California. The bays of the building (single story) are approximately 60' square. I am assuming a 10 psf roof dead load and a 20 psf live load. After going through the seismic design I have come up with a seismic design category E. As mentioned above this is a preliminary design and it is not known at this time what the interior bay framing will be, therefore I have assumed a "Special reinforced concrete shear wall" bearing system.

My analysis of the above mentioned variables gives me a 16" concrete wall panel with #8 bars at 4" centers to accomidate not only the moment in the wall but the deflection criteria as well. My questions is does this wall panel appear to be over sized and if so does anyone have any good references that they might suggest.

Thanks for your help in this matter.

 

[JAE]

Your analysis - did it give that reinforcing for two layers? or one layer in the center? I would presume its two layers.

Concern with slender wall elements - and load bearing/high seismic at that - is that second order effects would be quite pronounced and a major concern in terms of calculating it right.

The thickness appears to be about right - generally H/50 is a good starting point for tilt panels.

 

[CowboyBill74]

JAE

Yes your are correct the reinforcing will be in two layers and the fact that the second order effects where the controlling design factors. Thanks for the rule of thumb for starting thinckness of the tilt wall panel.

I will go ahead with my preliminary design knowing at least I am in the ballpark.

 

[whyun]

What is the length of the 16" thick by 70'-0" high panel? Verify the maximum lifting loads from the available cranes and ensure that the weight of a single panel does not exceed the crane capacity.

 

[haynewp]

I have never designed a panel that big, you may want to talk to Dayton Richmond or some other tilt lifting design company about the thickness you have come up with. Sometimes the lifting stresses on a panel can be significant and they may have some advice.