ABSTRACT
Based on the results of the experimental and theoretical studies, an engineering method is developed for calculating the final settlement of single, multiple blade helical pile in clayey ground. It has been found that once the pile is screwed into the ground, the sections between its blades assume the form of a “ground cylinder” that joins together with the shaft to interact with the surrounding ground. In our method for calculating the pile settlement, the action of the lateral surface of the pile (the first phase of loading) and of the bottom tip (the second phase of loading) is analyzed separately. At the first phase of loading, the shear deformation around the “ground cylinder” causes the settlement to be of linear dependence, and the settlement is determined based on the results of lab analysis of clayey ground in direct shear apparatus. At the second phase of loading, the pile settlement, influenced by the action of the bottom blade in clayey ground, is of non-linear dependence and determined using Malyshev-Nikitina method (1982). Benchmarked against the results of numerical modeling of multiple blade helical piles’ performance in the clayey grounds of semisolid to semifluid texture, the results of calculation have shown that the proposed method has the accuracy high enough for it to be used for engineering calculations of settlement.
