Tangent Modulus for Uplift Loading
Author: Jeremy Ferris
I'm performing a Settlement/Uplift analysis for a drilled shaft pier foundation using Elastic Methods. The Uplift equation I'm using comes from the Pennsylvania DOT design manual. PADOT references N.S. Mattes and H.G. Poulos, "Settlement of a Single Incompressible Pile"(1969) and J.L. Withiam and F.H. Kulhawy, "Analysis Procedure for Drilled Shaft Uplift Capacity"(1981).
The uplift equation replaces the Elastic Modulus used in the compression analysis with the Tangent Modulus, Et. What is the Tangent Modulus? Is there a resource that has various values for the Tangent Modulus based on soil type?