Precast Wall Panel - Joint Width

[Structures33]

It looks like there are a few joints between the precast wall panels that are too wide for the typical connection. In the attached photo, the lower 3 connections were welded but the upper 2 were not. It looks like the joint may have been slightly larger at the upper 2. I assume they will use a different method to connect the panels, but am wondering how common this is and curious to hear any other thoughts??

 

[Structures33]

sorry here's the photo

 

[asixth]

Depends on how much construction tolerance the connection allows. We provide oversized holes in our plates which allow 20mm tolerance (3/4").

 

[rowingengineer]

I would avoid the connection, no need to weld panels together for structural purposes that I know of.

An expert is a man who has made all the mistakes which can be made in a very narrow field

 

[structuresguy]

I don't see any problem from the photo you posted. And I only see one connection made and one not made. Can you elaborate? Is your connection just a steel bar inserted between the precast, and then welded to embeds each side? If so, and your panel joint is a little wider than normal, can't you simply get a larger diameter steel bar to suit the actual joint width?

We normally specify a 3/4" wide joint, but frequently have seen it end up being double that, and sometimes even more. On a big building, an 1/8" tolerance at each joint can add up to quite a lot at one end, depending on how they erect the panels. So you should put some verbage in your specs concerning accumulation of tolerances during erection.

 

[structuresguy]

rowingengineer: I can think of many structural reasons to connect the panels. The main one to make them behave as one continuous shear wall, rather than a series of individual shear walls. Another is to make sure that there is no differential movement out of plane between panels, which could easily lead to premature sealant failure. While on typical tilt-up building (warehouse style) I would not connect the panels, I frequently do connect panels in more complex buildings, such as multistory office with lots of openings.

 

[Structures33]

The photo is only showing two of the 5 connection points (they are tall walls). If I use a photo of the whole thing you wouldn't be able to see the joint well enough. This post was a piggyback on my previous one regarding cracks at the connections so I didn't explain in this post -- I am not the engineer on the project. I'm only doing periodic construction reviews. The drawings that I have do not have this connection detail shown - apparently they were revised after the construction set and I haven't received the revisions yet.
This is a very simple (but very large) warehouse.

 

[hokie66]

structuresguy,
Have a look at his other post for what happens when you weld the panels together.