Drilled Shaft subject to lateral loads & torsion

[STRengineer007]

I am designing drilled shaft sign foundations in SAND and I am getting very deep foundations using the BROMS method and side friction. There must be a better approach to designing drilled shafts under lateral and torional loading. One that can take advantage of the head pressure on the shaft from the wet concrete. Any references or ideas?

 

[jdonville]

STRengineer007,

Have your geotech perform a LPile (p-y) analysis.

Jeff

 

[jheidt2543]

You might find the paper "Analysis and Design of Laterally Loaded Piles and Caissons in a Layered Soil System", by T.R. Naik and A.H. Peyrot. It was published in the 1970's in an ASCE journal. The paper is based on a modificaiton of Broms' method and it has a very practical approach with a good example problem and a pretty extensive list of references.

 

[MedNeuvo]

How do we apply tortional load with Lpile for the design of a drilled shaft?

 

[Grouser]

STRengineer007

See the link below for Florida DOT design standards. I recall that "wings" are added to the shaft to resist torsion rather than resorting to excessive shaft length. I haven't opened the file as it may require microstation which I don't have.
See
Drilled Shaft Design for Sign and Signal Structures, v1.1,
at

http://www.dot.state.fl.us/structures/StructuresManual/CurrentRelease/FDOTBridgeManual.htm

Hope this helps.

 

[DirtDr]

The software application ALLPILe also can include torsion loads as well as lateral loads. Did you consult with the Geotechnical Engineer on the project for soil parameters or methods of analysis?