How would you connect a cantilever retaining wall to a composite slab of a semi buried house

[octagie]

What would be the most appropriate way to connect a cantilever retaining wall to a composite deck slab of the interior steel building, of a semi buried house? So it works as simply supported. The composite deck passes over the wall. Can't find any similar detail anywhere that addresses both structural and envelope concerns, plus constructive. Can you guide me? See attached sketch

Kind Regards.

 

[jayrod12]

How about just a steel angle(or channel or girt as support spacing dictates), sized appropriately, running between IPE beams or SHS columns. What is the spacing of the beams? What's the spacing of the columns?

 

[JoelTXCive]

Could you print to PDF or attach an image versus the .DWG file? More people will be able to see your question then.

 

[jayrod12]

Here's a screenshot of the DWG area in question

 

[hokie66]

Why would you want to connect the wall to the floor? Probably best to allow them to move independently. As to making the cantilever wall into a simply supported wall, that won't happen unless you cut the wall loose from the footing.

 

[KootK]

Is the wall an existing element?

 

[JoelTXCive]

Once you start attaching things, It will no longer be a cantilevered retaining wall.

Another thing to think about are earth pressures. Most retaining walls are allowed to deflect a little bit, which drops the earth pressure into what's called the active condition.

If you fix the top of your wall with that concrete going over to the shallow footing, then no movement will occur. That means the wall will see much higher earth pressures.

 

[octagie]

Spacing between frames is about 5 m.

No it is not an existing wall, but the likely constructive procedure the contractor will do is to build the retaining wall first and then the steel structure will be placed ( i would do that). The soil has good cohesion and can stand by itself during construction, so an alternative I wanted to explore is to cut less material and build a smaller foundation, by connecting the wall to the house at a floor level hence providing lateral support at the top the wall. Maybe the cost savings in steel mesh, earthworks and concrete are not relevant (I haven't checked), but seemed a good idea.

I'm primarily concerned with the fact that the concrete wall is an element exposed to the ground (humidity, etc.) and connecting it with steel directly might bring problems from the standpoint of building science, and more problems for the architect.

Another idea was to specify ground anchors but this is the kind of specs that scares small contractors at least here.

Connecting it to the perpendicular beam with some adhoc steel bracket might bring torsion issues, the ideal would be to connect it with the slab, or maybe a C channel only for that.

Regards to all .

 

[KootK]

This is a pretty common version of this connection although I don't know that it solves any building envelope issues with respect to moisture or heat loss.

 

[octagie]

It works in that situation but in this case the slab goes over the wall so it wouldn't work I think.

An UPE beam with shear connectors might do it, see attached, but would it be difficult to build?

Regards.

 

[jayrod12]

Are your IPE beams also spaced at 5m?

If so, why not just run the wall right to underside of steel deck, provide pockets through the wall for the beams, provide a weld plate in the top of wall to fasten the deck to. I don't understand why this is so difficult. If this is a new build this is how I would be doing it, and not even putting a second thought towards it.

 

[KootK]

It works in that situation but in this case the slab goes over the wall so it wouldn't work I think.

Sure it would. Just stop and restart the deck on either side of the wall.

An UPE beam with shear connectors might do it, see attached, but would it be difficult to build?

That does look difficult to build. Given normal construction tolerances, I'm not sure you could count on a snug fit between the channel and the wall. Moreover, the channel would make for a pretty nasty thermal break.

Some questions for you:

1) How is your slab to be formed? Composite metal decking? Temporary formwork?

2) What are you goals here from a building envelope perspective? Moisture control? Heat loss? Both?

3) Do you require allowance for vertical slip at this connection? Your latest detail suggests that.