Comparison of different methods to predict pile settlement

Abstract

This project compares the accuracy of three methods commonly used to predict settlement in pile design, the first is the analytical solution empirical method of Poulos and Davis, the second is the empirical method of Vesic, and the third is the finite element method, which uses the finite element simulation software ABAQUS for predicting pile settlement. In the prediction of settlement of GEO Report No. 38 pile No. 58, the finite element simulation method (ABAQUS) has the highest accuracy, followed by Poulos and Davis' method, and Vesic's method predicts the pile settlement with the largest error. This may be due to the fact that Vesic's method is based on a large amount of field experience, which makes it difficult to accurately predict the pile settlement once the soil and pile conditions are different. And the sensitivity analysis of pile settlement was carried out in ABAQUS with the same modeling approach through the control variable method to derive the elastic modulus of the soil has the greatest effect on pile settlement, followed by Poisson's ratio of the soil, the internal friction angle, and cohesion of the soil has the least effect on the settlement of the pile. The same control variable method was also used to derive that the closer the soil layer to the pile end, the greater the effect of parameter changes on pile settlement. The mean and variance quantify the effect of parameter change on pile settlement for each layer of soil. And a score system was introduced to evaluate the influence degree of the parameters, and then the model was corrected by the influence degree, and the results showed that the corrected model's settlement curve had a higher degree of fit with the real settlement curve, proving that this sensitivity analysis could improve model accuracy.