Reinforcement design for laterally loaded piles 1

[killswitchengage]

Hi

This is my first time designing a secant pile wall , can somebody please show me a guide or whatever so i may design the reinforcement for piles ?

Thank you

 

[GC_Hopi]

Do you have a specific design code that you are to follow, like a DOT or city code? Usually those are good starting places. If not you can google FHWA or US Steel, they have guides for secant walls.

 

[STrctPono]

I assume that you are at least well versed enough to determine the external loading on the pile (since your handle has you listed as a Geotechnical Engineer). If you know the load, you can figure out the internal moment and shear demand on the pile. From there, determining the shear capacity is relatively straight forward. You can either use ACI 318-14 Sections 10.5 and 22.5 for calculating the shear capacity. Shear capacity rarely governs. As far as moment capacity goes, it's a bit more involved given the shape of the pile and the time it might take for you to figure out the effective depth of the reinforcing steel but you could follow ACI 318-14 Section 22.4 OR.... you can take the easy route and use a program like PCA column to calculate it for you. Since secant piles are predominately in flexure with little to no axial demand, you don't need to generate the full P-M interaction diagram. AASHTO also has applicable sections that address this as well if that is what you need to be using for your project.

 

[PEinc]

Or, if you know the loads, just design and insert a steel beam (soldier pile) in alternate drilled shafts.

http://www.PeirceEngineering.com

 

[STrctPono]

You could also do what PEinc suggests. This is more of a regional preference thing. In my area, building a small rebar cage is a lot more streamlined and easier (and probably cheaper) to do than to get some wide flange sections. Other areas of the world may be different. You need to know what the general state of practice is in your region.

 

[killswitchengage]

Hi
Yes I do have the max bending moment and shear effort applied on the pilei was just looking for a way to design the rebard cage. Ps steel beams are quiet expensive in my country

 

[PEinc]

"Ps steel beams are quiet expensive in my country." Consider the labor to fabricate and set the long rebar cage and possibly tremie pour the concrete through the cage vs. setting a steel beam and dumping the concrete.

http://www.PeirceEngineering.com

 

[PEinc]

The decision for using rebar cages vs. steel beams may be influenced by whether or not the alternate piles need tieback anchors.

http://www.PeirceEngineering.com