Unusual soldier pile and lagging scheme
Unusual soldier pile and lagging scheme
(OP)
I need an opinion on a contractor’s proposed soldier pile and lagging scheme, see sketch. He’s rebuilding a bridge abutment in stages and can’t drive sheeting. The abutment isn’t very tall and sits on a mat foundation. The sheeting would have to go through the mat.
Toward the rear of the work area he wants to drive piles a few feet in and hold them with braces that would be wedged against the wingwall – I’m OK with the concept. However, near the front of the abutment he wants to drive two soldiers two feet below his demolition line and rely on two walers acting as cantilever beams to hold the piles in place.
In theory I see his point but I’m not convinced. I was thinking of stacking some mafia blocks on the "cantilever". It will interfere a bit with the formwork but they should be able to work around it.
Toward the rear of the work area he wants to drive piles a few feet in and hold them with braces that would be wedged against the wingwall – I’m OK with the concept. However, near the front of the abutment he wants to drive two soldiers two feet below his demolition line and rely on two walers acting as cantilever beams to hold the piles in place.
In theory I see his point but I’m not convinced. I was thinking of stacking some mafia blocks on the "cantilever". It will interfere a bit with the formwork but they should be able to work around it.

RE: Unusual soldier pile and lagging scheme
In my experience, stacked mafia blocks usually have an insufficient safety factor for sliding unless they are about 4 feet wide, front to back, and unless the retained height is lass than about 4 to 6 feet. This is especially true when the stacked block wall needs to support a traffic surcharge.
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RE: Unusual soldier pile and lagging scheme
What I don't like is the skewed brace and the apparent random location of the braces (for this cantilever loading). I would put all braces (horizontally) perpendicular to the wales and position them directly opposite the driven piles. This would make the wale loading easier to predict. Other than that, don't have a good reason for my suggested brace placement... just seems to be the right thing to do in this situation.
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RE: Unusual soldier pile and lagging scheme
SRE - I don't like the skewed brace either. Turning it back to get an end support would be tough. After the "cantilevered" wall I was going to place the braces perpendicular to the walkers and support them against the wing wall. I'm a little less wary of the idea now. I might be able to temporarily tie the end pile to the stringer, to give the end section more support.
RE: Unusual soldier pile and lagging scheme
www.PeirceEngineering.com
RE: Unusual soldier pile and lagging scheme
I would prefer soldiers without wales & bracing. There's only 16' from top of pavement to top of footing; so the pile tip is on the footing. Might be able to sharpen my pencil and make it work. The wall is probably 20' long tops.
RE: Unusual soldier pile and lagging scheme
www.PeirceEngineering.com
RE: Unusual soldier pile and lagging scheme