Review of Computational Models and Methods for Predicting Ultimate Capacity of Uplift Piles with Uniform Cross Section

Abstract

To improve the application of uplift piles, the calculation method for ultimate bearing capacity is analyzed to study the significant difference between the calculation and test values of bearing capacity. The computational methods for the ultimate capacity of uplift piles are analyzed on the basis of three failure surfaces. A comparative analysis of the results is performed on the basis of the field test. Results show that (1) the standard Meyerhof and Das methods ignore the self-weight of pile, thus making the calculation value smaller than the test value, such, that these methods can be applied only to uplift piles with small length-diameter ratio; (2) the Chattopadhyay method can predict the bearing capacity of sand, but the process is complicated; (3) the Shanker method considers the value of embedded length-diameter ratio and can therefore be used to predict the bearing capacity when the ratio is larger than 20; and (4) the truncated inverted cone considers the self-weight of pile, the Kotter method is based on the Kottei equation and the horizontal slice method assumes that the failure surface is curved, and all three methods base their, calculation of bearing capacity on ultimate equilibrium theory. The values from the three methods are close to that of Vesic test, such that these approaches can be used to compute for the ultimate capacity of uplift pile with uniform cross section under different soil conditions.