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Eccentricity by Wall-Slab connection

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Ey_2

Structural
Oct 23, 2020
25
Hi I have another question in regards to the precast wall to slab connection. Other than the previous one, this is for load bearing wall to slab. (I have had a look on the manual that I was recommended by still want to know your thoughts).

I have these 200mmx800mm panels with 4m spacing that attached to the slab and I wanna make them load bearing. I have put the design strip in light yellow and have no problem if the walls can be placed under the slab. But Now because the wall have to be placed outside of the slab and with the eccentricity by caused by the connection I am wondering if it is still doable? (Dowel bars are used to connect wall to slab)

I have uploaded the layout plan as shown below. Thanks in advance.

8008_a6jlwv.png
 
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I'll provide a bearing seat below the slab, either a corbel cast with the precast wall, or angle.
 
So dowel together with bearing plate? (I will have some recess in the panel anyway). Does dowel bars have to be designed to take the torsion coming from the design strip due to the eccentricity?
 
Yeah, with that dowel connection it's tough to know how much moment you'll force into the wall panel -- potentially a lot. I like R13's corbel idea as a means of ensuring a somewhat predictable amount of moment gets delivered to the wall. Do keep in mind that I'm a North American practitioner however. As far as I know, we don't really mix CIP slabs and precast wall panels here so my concerns may just result from a lack of familiarity with the system. Hopefully you receive some feedback from some Australian engineers as well.

C01_urwwyc.jpg
 
Yes, you need a moment connection here, that is the upper dowel should be fully developed into the precast wall/column, and both the upper and lower dowels splice to the slab reinforcement. The seat/bracket below will reduce the shear span, and help to carry the gravity and lateral loads. You have to make sure the precast panel is capable of acting as a column though.
 
To clarify, two of the goals of my detail proposal are:

1) minimize moment transfer from slab to wall and;

2) make whatever moment is transferred somewhat predictable.

I feel that moment transfer is not your friend in this situation.
 
KootK,

In general I agree moment connection is not a good idea, but I am worried about lateral stability of this system. I think he will also need beams in the transverse direction, then the columns are not lined up! A better layout is in dire need.
 
Thank you r13 & KootK! I will be looking into precast connection design before asking more questions :)
 
Make sure you have lateral load resisting system build in your model, either moment frame or shear walls.
 
Any fire resistance rating required?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
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