retaining walls

[John Dirks Jr]

I'm looking for documents and diagrams that describe how wood retaining walls should be built. I'm specifically looking for information on tiebacks. How many are needed for a given area and how they should be spaced. Stuff like that.

Here is a document I found. Do you think the info there is worth using as a standard?

http://www.fallschurchva.gov/Content/Do ... etails.pdf

If you can post any other diagrams or photos that would be great. Ones with information on measurement distances of tieback placement and joint offsets would be even better.

[Phillip]

John,

The document looks good to me.

I added it to my files.

Thanks

[Jim Katen]

I'm looking for documents and diagrams that describe how wood retaining walls should be built. I'm specifically looking for information on tiebacks. How many are needed for a given area and how they should be spaced. Stuff like that.

Here is a document I found. Do you think the info there is worth using as a standard?

Personally, I'd recommend that an engineer design a specific wall for a specific site. Conditions vary enough that a prescriptive design will have limited value.

That said, the document you posted looks ok if you don't want the wall to be more than 5' tall and if you don't stack the walls, but I have three quibbles with it.

The word "gravel" is imprecise. In my area, the word "gravel" usually means a mixture of crushed rock of a certain size along with rocks of a smaller size, all the way down to fines. This kind of gravel can be compacted and it doesn't drain well. When fully compacted, it actually sheds water. So it isn't really much good for drainage. I prefer to use the terms "drain rock" or, "clean river rock." I'd go so far as to actually warn against using rock that contains fines. Drainage is hugely important with retaining walls and the wrong kind of gravel can cause the wall to fail.

Figure 10 says, "Grease portion of bars extending across joint to prevent movement." I think the author meant to say ". . . to allow movement."

Figure 15 shows the connection between the footing and the wall and gives three options for that connection. The rebar and keyway options are fine, but I would never advise someone to rely on roughening the top of the footing prior to placing the wall and relying on that to prevent the lower portion of the wall from kicking out. There's too much lateral pressure there to rely on something as vague as "roughening."

- Jim Katen, Oregon

[kurt]

All the spec's I've ever seen for stone fill indicate "no fines". It matters.

[hausdok]

Jeez,

How many times have I gotta say it; the first place you should go for info is the reference library on this site.

Go to the library, click on "File Downloads", then scroll down to FM 5-426 - the Army Carpentry Manual - and go to Chapter 10.

ONE TEAM - ONE FIGHT!!!

Mike

[John Dirks Jr]

Thanks for the help and opinions everyone. Especially good to focus on the gravel/stone type.

Mike,

I checked the document you suggested. Wow, that one is loaded with info. Thanks. While I was poking through the other stuff in the library I found a bad link. The one for Tyvek is coming up as 404 not found.

Here is the link to it.

http://www2.dupont.com/Tyvek_Constructi ... K16282.pdf

[hausdok]

Hi John,

Thanks for informing us about the bad link. What category is it in?

OT - OF!!!

M.

[John Dirks Jr]

Hi John,

Thanks for informing us about the bad link. What category is it in?

OT - OF!!!

M.

File Downloads. Tyvek Water Resistant Barrier Installation. It's the 5th file down from the top.

[hausdok]

Hi,

Kewl! Thanks, I've replaced it with the Tyvek Architect's Binder. It has descriptions of all of their various products plus the installation instructions. It's much more useful than the wrap guide ever was.

ONE TEAM - ONE FIGHT!!!

Mike