Soldier pile retaining wall deflection

[milkshakelake]

Is there a code reference for allowable deflection in a soldier pile retaining wall? It's about 13' tall with 3x8 lagging, holding back sands. The use of the retained soil is sidewalk and backyard. I'm currently calculating 3" to 5" (depending on the steel size), and it seems high to me. But I want to know what ballpark to be in.




I found an older thread discussing this topic, but it didn't truly get resolved: https://www.eng-tips.com/threads/allowable-deflection-in-soldier-pile-ret-walls.103897/

 

[DaveAtkins]

I don't think there are any hard and fast rules. In your case, how much vertical settlement will result from that much lateral movement, and is the settlement acceptable?

 

[milkshakelake]

I'm not sure how to calculate vertical settlement of a soldier pile. I consider lateral earth/surcharge loads. Since they're not loaded axially like gravity piles, I don't consider vertical settlement.

The previous thread also mentioned that there aren't rules about it, and 1" horizontal deflection is kind of a baseline. The thing is, if the 1" limit were true, many cantilever pile installations wouldn't work design-wise. So I'm trying to see if there's some code reference or published material about this.

 

[KootK]

I've seen transportation agency limits on the order of max [2", 1.5%].

Like a lot of things dirt, much seems to rely on the design loads almost never fully materializing.

 

[milkshakelake]

Thanks @KootK , that seems more reasonable than 1".

Agreed about design loads not materializing. Many soldier piles I designed had very large movement if we're going with calculations, but in reality, it was negligible. Part of it is the large surcharge loads that won't happen, like 60 to 300 psf.

 

[Retrograde]

The deflection limit should reflect the specific situation. What I mean by that is that if there is a historic building close to the wall then you probably should aim for the 1" limit. Similar if there are services located in the ground adjacent to the wall.

It it is just a backyard then maybe 3" is OK.

 

[EireChch]

75mm is way too much for a 4m wall.

That should be 50mm max and even that’s excessive