Steel Bldg LFRS

[Eren Jaeger]

Hi!

If you have to conduct a structural design on a 4-storey dormitory steel bldg, what lateral force resisting system would you use?

I'm thinking to use Special Moment Frame on the strong axis and Special Concentrically Braced Frame on the weak axis of the W Shape columns. But my problem is, how would you conceal the bracings inside the walls? Let's say if I want to use CHB for the partitions?

So I'm thinking, maybe using shearwalls are more preferable than SCBF. But in that case, how would you connect the concrete shearwalls to steel columns?

What are your thoughts? Thanks for the reply!!

 

[KootK]

If you have to conduct a structural design on a 4-storey dormitory steel bldg, what lateral force resisting system would you use?

This will depend on a ton of things. Where is the building located? What is the preference of the owner/contractor/architect? What floor and roof systems are desired?

But my problem is, how would you conceal the bracings inside the walls?

With some difficulty and great coordination with the architect. A moment frame within a wall can be expected to drift a fair bit within that wall. Either system done "special" is likely to have fairly stocky members and connections relative to standard partition wall widths.

But in that case, how would you connect the concrete shearwalls to steel columns?

You likely don't need to and would only need to connect your shear walls to your floor and roof diaphragms.

 

[Ceinostuv]

Apparently the Mods are more concerned with my attempt at a jest to build some camaraderie than they are with policing members who make derisive and condescending posts when responding to questions. Go figure.

As KootK mentions, moment frames tend to have higher drifts than other lateral force systems. If you are required to isolate your cladding from the core and shell, this may end up incurring additional costs when it comes to the cladding design - whether or not this balances out when you examine the overall project costs, I do not know; but, it can definitely be a burden when designing exteriors.

Hiding a frame within a wall is doable, but I would recommend that drift compatibility between the wall and the frame be considered if you end up using a braced frame system. Technically and typically, interior walls are not drifted (read: isolated), however; when you hide a braced frame within a non-bearing wall, you may want to consider whether the finishes may be affected as the lateral system drifts. If the drift is high, you run the risk of cracking the finish (or the CHB) if the wall is not properly isolated. I have designed a few light-gauge walls to conceal braced frames; we usually end up with expensive isolating systems or having the EOR or Arch. accept the possibility of a cracked finish after a wind or seismic event.

The joke that the mods removed had to do with utilizing hardened titans as a lateral system. Hopefully, since I have now added my $0.02 and removed the joke, no one is offended any further.

Judgement-In-Training