I am making the structural design o 1

[serdardundar]

I am making the structural design of a light gauge residential building with 1.5 storeys. All inner and exterior walls are load bearing walls. I may choose to make inner walls only carry loads in vertical direction. But i have difficulties in disributing the lateral loads. The inner walls are not aligned vertically. Can i assume all the lateral load of the upper half story is carried by the exterior walls? And no lateral load is carried by inner walls. There is also another problem ; the ceiling of the upper story is at a height between the height of the exterior wall and top of the roof. So that it is suspended to the roof and supported by the inner walls only. So is the assumption of "all of the lateral load is carried by exterior walls only" still valid ? The ceiling of the upper story may distribute lateral load resulting from the dead load of the roof to the inner walls. I can provide some drawings if required. I really need help to solve the problem. Thanks for your help...

 

[ishvaaag]

In general you can use if you want only some walls to take the totality of the lateral loads as long such lateral loads are properly carried to them by stiff and strong enough elements. Then you dimension every item for the assumption taken. I have somewhere the requirement for the stiffness of the floor to be considered stiff enough but don't remember which the code was (I think was one of the US Navy) and in which book it was referred to.

For your 1 1/2 setup you need to assure you are passing the loads to hardpoints (collectors, bracing?)

Some further considerations may be needed pertaining to the compatibility of deformations between walls (or the way of designing the inner walls, for normally they will share the drift to some extent -less that the external only will assume). This causes different ways of calculation in the buckling of supported and supporting columns for structural steel and maybe something must be made about in deck-like construction as well.

 

[LPPE]

As you may know, in wood frame construction, you may use plywood shearwalls for lateral resistance.

I have heard that there are now allowable loads for plywood shearwalls with metal studs. I do not know where to find this information, so if anyone has heard of this, please let us know.

 

[Taro]

pylko,
Check out UBC 2219, IBC 2211, and APA Report 154 for steel stud shear wall information.

 

[serdardundar]

I know allowable loads for plywood or OSB shearwalls with metal studs. They are freely available on the web page:

http://www.steelframingalliance.com/pubs/techpubs.html

But I did not receive replies to my questions yet....(except
ishvaaag, thanks...)

 

I agree with ishvaaag concerning the design of the walls. You can assume all the lateral load of the upper half story to be carried by the exterior walls, BUT design them under this assumption.