Abstract: The static loading test curves of helical piles are fitted by the Richards model and the axial bearing capacity of the test piles are estimated. The results indicate that the Richards model is better than the power index and hyperbolic models in the curve fitting. Both the curve fitting and the accuracy of the prediction can meet the requirement of the projects. The results also verified that the feasibility of applying Richards model in the static testing of helical piles.  

Key words: Helical Piles, Richards Model, Ultimate Axial Capacity, Capacity Estimation