Can elevator shear wall thicknesses change?

[member 1218881]

Can elevator curtains be designed in different thicknesses in areas where elevator cabins are located in high-rise buildings? So, can elevator systems be designed according to varying curtain thicknesses? Have you actually encountered such a situation?

 

[KootK]

Are you asking about using thinner concrete walls in upper story's where shear wall demand is lower? If so:

1) it's common to make the walls thinner while keeping the interior flush an allowing the exterior to step inwards.

2) I've never seen the step made to occur on the inside of the shafts. I'm sure that it's possible to do that but, then, the rail attachments etc would probably have to take up the change in thickness. Obviously, the rails themselves need to be continuous all the way up.

 

[phamENG]

To KootK's #2, the ASME elevator code does not allow steps. There is a minimum slope - something like 4 units vertical to every 1 unit horizontal - where you have a chance in interior dimension. It's been a long time since I encountered that.

 

[member 1218881]

I've never seen the step made to occur on the inside of the shafts. I'm sure that it's possible to do that but, then, the rail attachments etc would probably have to take up the change in thickness. Obviously, the rails themselves need to be continuous all the way up.

To KootK's #2, the ASME elevator code does not allow steps. There is a minimum slope - something like 4 units vertical to every 1 unit horizontal - where you have a chance in interior dimension. It's been a long time since I encountered that.

As seen in the figure, there are 3 elevators. The width of the cavity is approximately 795cm ​​x 310cm. However, in the part you see with the yellow marked line on the left, the shear wall narrows and the gap becomes 815cm. My idea in this part is to adjust it with steel profiles and fit the elevator rails to the steel profiles. Since the space is large, the elevator rails will most likely be positioned on the steel profiles created inside the shear wall, rather than on the shear wall.

With a more accurate technique, I can make this narrowing at the back of the elevator, not in the part where the two rails will come. In this way, there will be no narrowing on the surfaces where the elevator rails are located. What kind of an idea do you think this is?

 

[KootK]

What kind of an idea do you think this is?

I think that it's the kind of idea that needs to be vetted by a careful reading of the ASME document on elevators. I'd want to have a good understanding of the sloping requirement that phamENG mentions before proceeding with what you propose.

I don't know the spirit of that provision. Is it:

- to keep something from catching on the ledge on the way down?

- to keep birds from nesting on the ledge?

- ...

What I do know is that elevator folks are often not very amenable to liberalizations of their requirements. And that stance is surely justified. Elevators are big money items and have a disproportionate impact on life safety. It's probably not a great place to be trying out new things unless there is a very compelling reason to do so.

 

[mikek396]

The change in shaft dimensions is OK, However...

1 - the top of any setback greater than 2" needs to be beveled at 75 degrees
2 - the elevator contractor should be informed as they will need to adjust their bracket dimensions - the contractor should have a maximum bracket length. IME the ~8" change will be fine

Regarding moving the step to the back of the shaftway instead of the side - this will likely create the same issue, as this arrangement typically has the counterweight (and rails) at the rear of the shaft