Torsional Capacity of a Drilled Pier Foundation

SoilStructure Drilled Pier Software is one of the few programs where the engineer can investigate the Geotechnical & Structural Torsional Capacity of the Drilled Pier.  A recent study  by Oregon Department of Transportation, Final Report, SPR 304-701 was completed on May 2016. This report deals with Geotechnical Torsional Capacity.

The report can be downloaded from here:  and is titled “Evaluation of Torsional Load Transfer for Drilled Shaft Foundations” by Studlein, Barbosa & Li.

I have run the 3 examples shown in the Appendix of this report and compared it to results from Drilled Pier Software.  Below are my findings:

Case 1: Torsion of Drilled Pier embedded in Sandy Soil:


Case 2: Torsion of Drilled Pier embedded in Clayey Soil:

Case 3: Torsion of Drilled Pier embedded in Granular Fill over Clayey Soil:


The comparison indicates that SoilStructure Drilled Pier Software predicts well when compared with other methods of Torsional Capacity in various soil conditions.