Light Gauge Steel Building (G+3) Bracing System 1

[TekEngr]

Below is the plan of light gauge steel building size 75mx14m (G+3) as you can see we have a lots of internal partition walls for strap bracing in each floor and I roughly calculate the strap bracing sets for lateral resistance for each floor, for the required no of strap bracing sets we have enough space, so my question is that still I should provide the hot rolled portal frames in the building in intervals for lateral bracing or strap bracing will be enough please suggest me under your experience’s.
stairs are in hot rolled and wind speed is 0.90KN/m^2

 

[XR250]

If the numbers work out and you are confident that it will get installed properly then i do not see a reason for a portal frame.
I am not a big fan of strap bracing for multi-story buildings. The design and detailing is very difficult (if you are doing it properly) and it never seems to get installed worth a damn.
I actually only do light gage design for single story and non-bearing systems now for those reasons.

Saw an eight story hotel going up recently made entirely of light gage. I could not imagine it was cheaper to build than using structural steel. The size and spacing of the studs and straps was ridiculous.

 

[SnapperHG]

While I totally agree with XR250 regards X bracing, IF we / you use 'K' bracing (or sheathing as Timber frame) you SHOULD have no site issues.

I'm from UK and though lots of the guidance is paid for (Circa £50) (SCI, steelbiz.org) it's GOOD.

Bracing is one of my area's of interest shall we say. In the UK we work on limiting the 'horizontal force at the top of the 'panel' to 4.5kN to prevent cracking of the internal plasterboard. Their are 'caveat's, aren't their always! The 'panel' (or bay as I refer to it) is 2.65m high, and this in turn produces a compressive and tensile force in either side of the bay (pair of studs at 600mm (2') of AROUND 25kN (2.5Te) which is quite a lot!

Alternative guidance is available regards sheathing in BS 5268 (Timber code)and ED002 a guide from 2003, by the DTi (UK Government), SCI and Trada that included test work by what was then called British Steel, now Tata, or racking resistance of various 'sheathings' on LGS wall panels.

I can't 'market' or sell on here, and that's fair enough, but if you want to know more PM or go to my web sites -

http://www.mmcengineer.com

and

http://www.mess.uk.com

I've done 10+ stories ALL IN LGS across the world, from Monglia to Brazil and Mexico to Kenya, so it DOES work, and works well!

Steve Napper CEng BEng(Hons)
Director
Stephen Napper Associates
mmcengineer.com