Should a retaining wall be tied to a building? 1

[Nick4861]

Can anybody help me? I have been supervising a site that has retaining walls. The ends of the retaining walls occasionally end/meet at existing buildings i.e. garage/house.
I can not find any info anywhere regarding if the wall should be tied into the building.
Any info or guidance that could be provided would be greatly appreciated.
I have added a diagram to show basic design of the the wall.

 

[Nick4861]

I am being told to tie the wall to the building, I believe this to be wrong as if the wall fails it may bring the building with it which will obviously be occupied by residents.

 

[Celt83]

Unless you are checking the existing structures for the new reactions you would be applying to them with the retaining wall, I would design the retaining wall as an independent structure.

Are you increasing soil surcharge loading on these existing structures by adding a retaining wall adjacent to them?

I'm making a thing:

http://www.thestructuraltoolbox.com

(It's no Kootware and it will probably break but it's alive!)

 

[MotorCity]

If you are not the EOR, you owe it to him/her to get their opinion on this issue. My personal preference would be not to connect the retaining wall to a building structure as the wall and the building will most certainly not move in unison.

 

[PEinc]

I do not believe that retaining walls (especially non-gravity walls) should be tied into a building. Walls move; buildings do not (or should not). Differential movement will cause problems.

http://www.PeirceEngineering.com

 

[DoubleStud]

How high are we talking about here? Also, are you thinking about connecting it to the foundation of the building? I do not understand how soil can be against framed wall.

 

[JoelTXCive]

Every scenario is unique, but I would be hesitant to tie the walls to the building.

Walls are designed to move a little so that the active earth pressure conditions may be achieved. As soon as you start tie-ing the wall; you create a region of fixity; which means in-situ earth pressures can be created. Also, you can go from a 1-way cantilevered condition to a 2-way condition with horizontal moments & shears.

 

[dik]

You have enough 'NO' votes, I won't bother casting mine...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JLNJ]

The answer is: it depends.

For example, a basement is a retaining wall tied into a building.

 

[Tomfh]

It depends.

Sometimes a building is a perfect buttress for a wall, eg if the building wall is aligned to resist the wall thrust.

The usual concerns re. Differential settlement etc apply.

 

[Ron]

No.

 

[KootK]

In my area, and for new structures, it has historically been very common to dowel cantilevered retaining walls into basement walls where the cantilevered walls form the sides of the vehicular ramp down into the below grade structure. That, because it's not a location where anybody would be particularly thrilled about differential lateral or vertical movement. In these instances, the structural implications for both the basement and cantilevered walls are considered (or should be).

Where the tie-in would be made at an existing structure, I'd be more reluctant to connect the cantilevered walls to the main building basement walls. It still depends though. A three story below grade CIP wall under a tower and one story, unreinforced masonry wall under a house are wildly different animals. Your cantilevered wall looks pretty skookum to be leaning on houses at the ends.

 

[dik]

That's Ron, definitive as always... you missed the exclamation mark.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

Still not a good idea. The detail below is what I've often used if the space is to be reclaimed. It provides a good watertight joint. I've used it for retaining structures, building additions where a new foundation wall is framing into an existing wall and like a bunch of others...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[KootK]

Still not a good idea.

It's everywhere here, and in WI where I used to work. And I don't know of a single instance of it having caused problems in new construction. I believe that, sometimes, the building envelope wraps the corner of that joint a ways and, as such, is not a spot where differential lateral movement is desirable.

 

[dik]

You might look to an alternative joint.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik