Closure to 'Shaft Resistance of Drilled Shafts in Clay' by Tanusree Chakraborty, Rodrigo Salgado, Prasenjit Basu, and Monica Prezzi

摘要

We thank Dr. Diyaljee for his appreciation of our contribution to developing a scientific basis for drilled shaft design in clay and for his insightful discussion of our technical paper. The discussion summarizes well the main objective of the published research, which was to provide, based on sophisticated numerical modeling and analysis, a rational method of quantification of the shaft resistance of drilled shafts in clays. The effects of installation and loading on limit shaft resistance of drilled shafts in clays were quantified through the analyses, and analysis-based equations were developed to calculate (following a total stress approach) the coefficient α appearing in the equation for the limit unit shaft resistance q_(sL) = αs_u, which traditionally had been estimated based on empirical relations. The main points of the discussion are as follows: 1. The discusser is unsure as to whether our analysis considered multiple cycles of auger insertion and removal and asks as to the potential effect of the associated multiple shear loading-unloading cycles along the borehole wall on the limit shaft resistance.