Calculation method of bearing capacity of screw pile under compression load based on limit equilibrium theory

The problem of calculating the ultimate bearing capacity of screw pile has been studied by the limit equilibrium theory in this paper. The calculation methods of the critical screw pitch and the ultimate bearing capacity under two representative failure modes are proposed. Four key parameters affecting the ultimate bearing capacity are compared and analyzed, and the design optimization suggestions are put forward. The results illustrate that the ultimate bearing capacity of the screw pile is mainly affected by the shear strength of soil, the height of screw thread and the screw pitch. When designing the screw pile, the height of screw thread could be increased and the screw pitch reduced to some extent.