Steel-Frames to replace walls

[As-Lag]

Hello

I am working for an Architect who regularly takes out all the internal, and most of the external walls of a house and, on plan, the houses appear to be unstable. I am familiar with the notion of replacing the removed walls with a steel-frame or goal-post and I am OK with the frame analysis but I struggling to work out the forces that I should apply to the frame.

For example. I have a two-storey house (Ground floor and First-floor) that is a mid-terrace house of five. I have calculated the wind-pressures and applied them to the flank-wall of the terrace but I am unable to make the terrace move. How do I calculate the moments due to lateral forces in the frame, please?

 

[Agent666]

Being the middle unit of several, probably means the structure don't see too much wind load from the terrace ends. It will of course see load from the front/rear faces. If you're subject to earthquake loads you would see this in both directions.

One way to assess in a logical manner, would be to put back a similar level of resistance to which you are taking out. But naturally because a portal frame is probably far more flexible compared to the original walls, the frames probably won't see this load in reality. But like you say, you have to design for something and this seems like a logical approach based on exercising some engineering judgement.

The other units with walls at ground floor will to some degree end up supporting the unit in question, as the ground floor is much stiffer in the remaining units.

The problem comes I guess when everyone cuts out their ground floor walls to follow suit because they like what the neighbour did. So, it pays to put some structure back in that could take the middle units share of the tributary loading if this were to eventuate.

https://engineervsheep.com

 

[As-Lag]

Thanks. I will get back when I have worked out some ideas.