METHOD FOR CONSTRUCTION OF PILE AND COLUMNAR FOUNDATIONS IN PERMAFROST ZONE Russian patent published in 2024 - IPC E02D27/35 

FIELD: construction.

SUBSTANCE: methods for constructing pile and columnar foundations in the permafrost zone. The method for constructing pile and columnar foundations in the permafrost zone includes local thawing of the permafrost soil mass using steam heating with steam needles, the formation of a drilled injection pile or bored pile with geometric parameters and physical and mechanical properties specified by the design. After steam heating, a supporting soil-concrete heel is formed with the geometric parameters and physical and mechanical properties specified by the design, while the supporting soil-concrete heel is made in a cylindrical shape with a diameter D and height h _h in the form of a soil-concrete mass mixed with cement mortar and impregnated with a highly permeable mortar based on microcements, while the formation of the supporting soil-concrete heel is carried out by drilling a leader well with a diameter d and depth h _c , then using a drill rod equipped with a drill tip and a nozzle, a well is drilled at a height h _h , that is, at the location of the supporting soil-concrete heel. Next, a cement-water suspension and compressed air are supplied through the nozzle under a pressure of 450-500 atm and, by reverse stroke, gradually, without stopping the supply of these components, the drill rod is raised to the level of the top of the supporting soil-concrete heel, i.e. to a depth h _c , while creating a homogeneous porous soil-cement mixture within the volume of the supporting soil-concrete heel, after which an injection collar pipe is installed along the axis of the volume of the supporting soil-concrete heel vertically to the entire depth of the volume of the supporting soil-concrete heel, in the walls of which, at a certain interval, there are holes with elastic collars, through this pipe a highly permeable solution based on microcements is injected under a pressure of 5 atm. After hardening of the supporting soil-concrete heel, the body of the pile is formed by resting on the supporting soil-concrete heel or, using a rigid embedding type, a drilled injection pile or a bored pile is supported in the supporting soil-concrete heel, while the specified piles with the geometric parameters and physical and mechanical properties specified by the design are made with a diameter d and depth of placement h _c with a metal frame and a pipe for ultrasonic testing of pile continuity. The soil mass is not kept in a thawed state, but it hardens to design values that provide the necessary load-bearing capacity of the pile foundation in both thawed and frozen soil, followed by a transition to a frozen state.

EFFECT: increasing the reliability of pile and columnar foundations in the permafrost zone.

1 cl, 2 dwg