مشخصات پژوهش

In this research, the response and behavior mechanisms of screw piles and their correlations under compressive loading in sandy soils are analyzed. The results revealed that the bearing mechanism of screw pile can be extracted from the pile response curve. At nonlinear part of the pile response curve, screw pile acts individually and the shear strains within the soil are concentrated near the helix plates. The displacement and the load where changes in pile bearing mechanism occur were identified and named as transition displacement and phase transition load, respectively. The shear strains of the soil around the screw pile develop around the helix plates and move to each other as the load increases to merge a soil cylinder between the helix plates. Bearing mechanism of the screw pile changes to cylindrical mechanism, when the applied loading value passes phase transition load. The main parameters of the pile response curve such as phase transition displacement, phase transition load, initial slope of nonlinear part and slope of linear part depend on the pile geometry and soil specifications.