Comparative study of theoretical methods for estimating pile capacity using 1-g model pile tests in cohesionless soil

The behavior of single pile is considered as the base of the most pile foundation design procedures. There are many different theoretical methods used to estimate the capacity of single pile embedded in cohesionless soil. In order to select the most accurate and reasonable method, 1-g model tests have been performed in this study. Different five procedures have been used to interpret the test results in order to select the suitable procedure. The statistical analysis showed that all procedures give approximate results except Chin's procedure which yields inaccurate results with respect to the average value. Then, the results of five theoretical methods have been compared with the measured pile capacity from model tests (average value). The rank index analysis was conducted based on statistical parameters and probability distributions. The results of the analysis yielded that Coyle and Casttelo method gave the most accurate and reasonable results than the other theoretical methods considered in this study (Berezantsev's method, Meyerhof's method and traditional bearing capacity equation with some modifications). Finally, the author recommended using the two tangents procedure in interpreting of the pile test results. Also, the method proposed by Coyle and Casttelo can be used to estimate the pile capacity based on soil properties with accurate results.