Tension cable bldg in California: How to jusitfy?

[thung621]

Hey fellow engineers,

Thank you for taking the time to read this. I'm currently working on a 2 story shear wall + a tension cable high roof building in California.

My question is if there is any way to justify the use of a tension cable structure in seismic design category D? This seismic force resisting type is not listed in table 12.2.1 of ASCE 7-05 so I was hoping to justify it as a nonstructural component in chapter 13 by using Fp level forces. The architectural compenent that most closely matches what I have is a penthouse per table 13.5-1, but does the high roof that I have constitute as a penthouse?

The high roof in my building is basically a pop up roof that is approximately 6.5 ft above the roof level. It is approximately 1/3 of the low roof area. I can make this high roof pretty light if it helps in justifying the use of tension cable bracing.

Thanks for reading this. Any direction would be greatly appreciated.

Sincerely,
Tony

 

[dik]

Check the West Coast Transmission Building in Vancouver, Canada... or whatever it's now called.

 

[thung621]

Wow dik, that is a pretty cool looking building.

I should have clarified my original post earlier by mentioning that the high roof is supported with gravity steel columns. It's just that laterally, instead of convential brace frames, the client would like to see cables instead.

 

[vandede427]

I'm glad you posted this b/c I might also be using tension only cables combined with wood shear walls on a prospective project. I wasn't sure what seismic system it fell under.

On one hand I could argue Steel Systems Not Specifically Detailed (R=4), but on the other I could argue that it's similar to Light Framed Walls with Flat Strapping (R=4).