Soldier Pile Design
Soldier Pile Design
(OP)
Hello,
I am currently trying to check a temporary soldier pile & Lagging Wall design (for estimating purposes). I know how to figure the embedment depth of the piles, but I am having trouble designing the actual soldier pile itself. Should I check LTB? It seems like the SP would be braced by the Wood lagging. Is it as simple as designing a steel beam for a moment and shear? If so, I am trying to use LRFD, what factors should I apply to the moment on the beam?
I am currently trying to check a temporary soldier pile & Lagging Wall design (for estimating purposes). I know how to figure the embedment depth of the piles, but I am having trouble designing the actual soldier pile itself. Should I check LTB? It seems like the SP would be braced by the Wood lagging. Is it as simple as designing a steel beam for a moment and shear? If so, I am trying to use LRFD, what factors should I apply to the moment on the beam?





RE: Soldier Pile Design
For most LRFD soldier beam projects I've done, the load factors are 1.5 for earth loads, 1.0 for water loads, 1.75 for live loads. Resistance factors have been 1.0 on soldier beam bending and passive resistance. I can't remember when shear was ever a controlling factor in one of my soldier beam designs.
If this is a highway project, you should check the DOT and AASHTO soldier beam design requirements.
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RE: Soldier Pile Design
For the Passive side, do you still use the .08*Phi*Flange Width to determine the tributary area that it takes?
Those load factors would be in addition to the SF. Correct?
Thanks for your helpful comments. I will definitely check DOT/AASHTO.
RE: Soldier Pile Design
RE: Soldier Pile Design
Never heard of (0.08 x Phi x Flange Width) for calculating the passive resistance width. Usually, the width is just 2 to 3 times the flange width or drill hole diameter if filled with lean concrete or flowable fill. However, 0.08 x phi is usually about 2 to 3.
The load and resistance factors provide the safety factor. You don't need to add another safety factor on top of the load and resistance factors.
Again, USUALLY there is no unbraced soldier beam length to consider.
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RE: Soldier Pile Design
For soldier piles you have the soil to 1 side, lagging at 2 sides, and points of support where at the heights the tie back action serves them as reaction point. The only face where buckling is possible is towards the void being made for the basement, and the situation is difficult to model more than anything because of the varying displacements imparted to the piles by the anchors to the ground. Anyway assuming the thing straight you have K factors of about .5 of the difference in height between the anchoring levels, that is not much for quite stout piles, and so scarce reduction in capacity is to be expected by this calculation. With ampler displacements like those caused by failure of anchor points we would see failure of the piles etc at bigger lengths of buckling but would be a secheme of overall failure behaviour of unlikely consideration for normal designs.
RE: Soldier Pile Design
The owner has already required a 1.5 SF on the wall by requiring KP to be divided by 1.5. Now my only problem is designing the actual Soldier beam.
For LRFD, I would simply use Mu=.9Mn where Mn is the max moment calculated. Then use Mu=Zx*Fy .
For ASD, I have seen Ma= Sx*Fya where Fya= .66*Fy .
These two methods produce vastly different sections, so I am concerned that something is wrong. Please advise.
RE: Soldier Pile Design
RE: Soldier Pile Design
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