Stability of Partially Embedded Foundation Piles

The stability of partially embedded foundation piles was first investigated by Granholm of the University of Stockholm (2).³ Granholm, upon developing an expression for the condition of buckling, proceeded to find its solution by means of an approximate method. The modulus of the foundation was calculated based on an assumed value for its rigidity. Experimental verification was conducted using thin-walled tubular brass specimens partially embedded in a clay foundation. The critical loads were in every case less than calculated values due, in part, to a complication of local buckling, particularly for shorter specimens. A relation was then found incorporating the local buckling effects, which fairly well represented the laboratory results. This technical note reports an investigation of the same problem, but the elastic foundation is assumed to be of the Winkler type and prismatic bars are used to avoid local buckling. The experimental results appear to confirm the analytical prediction.