Soldier Pile Design

[MacGruber22]

So I have noticed there are quite a number of empirical procedures to determine embedment depth of a soldier pile. The IBC and AASHTO have procedures that are super easy, but yield very different answers depending on how deep you are going. As usual, there is never the money to perform a true soil-structure interaction analysis, so we structural guys are left with choosing from the dozens of analytical methods scattered throughout codes, doctoral papers, textbooks, etc.

Does anybody have a ton of experience with soldier pile design that can provide some suggestions?

 

[PEinc]

Check the AASHTO Bridge Design Specifications. Any of their newer editions have earth pressure diagrams and equations for designing non-gravity, retaining walls with discrete vertical members (soldier beams). Other state agencies, like CALTRANS, have design guides dealing with these walls. For soldier beam walls, you will find more useable information in AASHTO that in most text books.

http://www.PeirceEngineering.com

 

[MacGruber22]

Thanks, PEinc

 

[MacGruber22]

After reading AASHTO 13.6.1.1 - Embedment for cohesionless soil, I am unclear how to proceed with this method.

They mention that Broms' procedure is for ultimate loads that require a undercapacity factor and overload factor. I have been given allowable passive pressure from the geotech. Does this mean I need to apply a load factor to the shear and moment in order to use Broms' method? It suggests using an overload factor of 2 to 3 - why does that seem so high? LRFD load factor would only be 1.6 for the retaining wall loads.

Thoughts?

 

[PEinc]

Probably anything you read about Broms was written before LRFD. Factor your driving loads (earth pressure and surcharge load). Apply a resistance factor to the passive resistance if a permanent wall. Apply the passive resistance to 3x the soldier beam width or width of the concreted drill hole. For a permanent wall, apply the active and surcharge pressures to the rear width of the driven soldier beam or to the width of the concreted drill hole for the soldier beam. Solve for the soldier beam embedment depth. Use it without any additional safety factor, but use about 5' minimum embedment in soil, less in rock.
Check the required load factors and resistance factors for the code you are required to follow.

http://www.PeirceEngineering.com