Soldier Pile Timber Lagging Wall 1

[DeeMIA]

Hello everyone, I am seeking your assistance with a particular project that I am involved with. I am working on an existing structure with below-grade levels. At the below grade levels, an exposed steel soldier pile with timber lagging wall is present at a portion of the building perimeter. During our investigation, we were curious about the condition of the steel soldier pile and whether it has experienced any section loss behind the timber lagging (the structure has been in service since 1975).

We removed a few pieces of timber lagging to expose the back side of the soldier piles and observed that the remaining flange and web of the soldier pile were protected by either CDF or some other form of lean concrete. This was only at the piles, and not the rest of the wall. After removing the cementitious protection, the steel turned out to be in really good condition.

We are now in the stage of putting everything back together, however, I would like to protect the soldier pile like it was originally being protected. Can anyone provide recommendations on what this cementitious material is and what can be used to patch it back? I cant picture how we can patch this back unless we use some sort of dry pack or we form up the locations (which could add up the cost). Please see a few attached photographs.

Any ideas will be helpful, thanks in advance.

 

[DeeMIA]

One other photo so you can become more familiar.

 

[GeoPaveTraffic]

Looks like sand cement grout. This was/is common practice in the mid-west. Once the soldier piles were placed in the drilled holes, standard concrete was used to the bottom of the planned excavation, then a lean sand cement grout was used to backfill rest of the hole. The grout could be easily removed with a air chipper and the lagging installed.

So any type of cement based material should work just fine.



Mike Lambert

 

[Bobby46]

Check out ACI 229 Controlled Low Strength Materials. They have some sample mix designs from DOT's. You can find it for free on google.

 

[milkshakelake]

Agree with other posts here, but as an additional thought, that looks rusted as hell. I don't understand why people use soldier piles as permanent retaining structures. They should at least galvanize it. If the owner has deep pockets, I'd say form a new wall next to it so the structure can last longer. The structural stability should come from concrete basement wall, not the soldier pile.

 

[MTNClimber]

Galvanized steel beams are typically very expensive. Sacrificial steel or coal tar epoxy is typically preferred on all the pile jobs I’ve worked on. I haven’t seen galvanized piles once.

I also don’t see an issue using a shoring as a permanent wall. What are your specific issues with it? If it’s designed correctly it should last.

 

[Ron]

Soldier pile walls with lagging are just fine. Since you've broken the cementitious coating, use either asphaltic or coal tar coatings to restore protection,

 

[milkshakelake]

@MTNClimber I thought that water and rust would eat away at it over the years, so I try to use them as temporary shoring. But if they've been performing well so far as permanent structures, then I see no problem.

 

[msquared48]

This is not just a soldier pile wall, it also has tiebacks showing. Hopefully, when the mortar infill was removed from the H pile, the tieback was not compromised. Not critical for temporary tiebacks, but could become a problem if they are permanent.

Mike McCann, PE, SE (WA, HI)