MULTI-BLADE SCREW PILE Russian patent published in 2024 - IPC E02D5/56 

FIELD: construction.

SUBSTANCE: invention relates to multi-blade screw piles and is intended for arrangement of foundations of buildings and structures of various purposes, supports of power transmission lines and communication, pipelines, bridges, advertising structures, residential and public buildings. Multi-blade screw pile, intended for operation in non-rocky soils, consists of a shaft, extension elements connected to the shaft, screw blades of the same size, located along the barrel length, and a conical tip. Screw blades are located within the bearing layer of soil with thickness of H_bl at a distance from each other l_b≥h_f×t_gφ(1+1/t_g²φ), multiple of screw blade pitch “a”, in amount of: n_b=(N−F_dƒ−F_do)/F_db for piles operating for indentation, where: l_b is the distance between the blades, h_f is the height of the flange of the screw blades, h_f=D−d/2, D is the diameter of the screw blades, φ is the angle of internal friction of the bearing layer of soil, n_b is the number of screw blades, N is the external load, F_dƒ is the bearing capacity of the pile shaft, F_do is the bearing capacity at the tip, F_db is the bearing capacity of the blade, for piles operating for pulling out, F_do=0, note here that shaft bearing capacity is calculated by formula: F_dƒ=ƒ×A_aƒ, where ƒ is the calculated soil resistance along the side surface of the screw pile tf/m² (averaged value for all layers within the immersion depth of the pile), A_aƒ is the surface area of the pile shaft displacement on the ground, is determined by the formula: A_aƒ=π×d[L_pl−n_b×h_f×t_gφ(1+1/t_g²φ)], where d is pile shaft diameter, L_pl is pile length.

EFFECT: increasing bearing capacity of the pile due to the design of the multi-blade pile taking into account the technological features of the formation of the stressed state of the soil in the zone of the blades location during the piles immersion.

5 cl, 2 dwg