Manager Says Keep the Restraints — I Think They’re Unnecessary. Who’s Right?

[ALphaSpace]

I’m working on a project where the architect has asked us to revisit the column and beam arrangement supporting an internal staircase. Image 1 shows the current set-up and image 2 is what i have said we can achieve:

• The column is an SHS 200x200x16, total height 10.8m to roof.
• It supports only a steel stair, no slabs or significant floor structure
• Axial load ≈ 150kN
• The column is currently laterally restrained at 3.6m and 7.2m, and again at roof level

The column sits in a 3-storey atrium space within a school, and the architect is concerned about the risk of pupils climbing on the restraint beams from the stairs. They have asked for these beams to be removed.

To accommodate this, I proposed that the column be cut back and terminated at Level 2 half landing (7.2m), which is where the stair ties in and is the final level it needs support. I checked the column assuming it’s unrestrained in the other axis, using buckling length factor of 2.0. The utilization came out at just 0.38, well within capacity.

I told the architect that, the restraints could be removed and the column could stop at Level 2 half landing.

However, my manager has now taken the opposite view and insists that the column must be restrained every 3.6m and extend up to the roof, regardless of the actual structural demand. He has already communicated this to the wider design team and has asked me to go back and tell them that the restraint beams are required, essentially reversing what I previously said.

While I initially agreed to do so, the more I think about it, the more uncomfortable I am. From a structural point of view, I don’t believe the restraints are necessary, and my calculations support that which i have shown my manager. It feels wrong to go back and push for a detail that I don’t believe is justified, particularly when it’s been requested to be removed for genuine safety reasons.

I would appreciate any thoughts? Opinions?

 

[rb1957]

don't double post ! ... this seems to have more response, so "report" your student forum thread, and ask for it to be deleted.

 

[Tex.Eng]

I agree with Rod above.

Additionally, I assume your manager is the stamping engineer (Design Professional in Responsible Charge). They should be the one to ultimately make this decision, especially because the restraint beams certainly don't make the structure less safe.

To alleviate the architects concern, can the restraint beams be round HSS? Or they can cover the beam in drywall in a shape which would make the beam less tempting to grab?

 

[BridgeSmith]

To alleviate the architects concern, can the restraint beams be round HSS? Or they can cover the beam in drywall in a shape which would make the beam less tempting to grab?

Making them round would probably help.

Also, extending the taller railing past the easily-accessible 'climbing on' point could help.

 

[ThomasH]

Do you believe vibration would be an issue? I could ulander stand for the sake of restraint beams to be kept if vibration issues are mitigated from the get go.

But not sure if a vibration would cause issue even without the restraints.

I just feel it’s way overkill.

Have you made any analysis regarding vibrations? You have a steel staircase, in a school, with a span of 7.2 m. That means that there can be a lot of people running in that staircase.