METHOD FOR FREEZING SOIL Russian patent published in 2022 - IPC E02D3/115 E21D1/12 

FIELD: building.

SUBSTANCE: invention relates to soil strengthening, in particular, to the drainage of pits by freezing, and can be used in equipping the repair pit on a pipeline in waterlogged and swamped soils. Method for freezing soil includes installing zonal freezing apparatuses in the selected zone and creating of an ice and soil barrier by nitrogen freezing along the perimeter of the repair pit; wherefor the perimeter of the repair pit is measured, the thermophysical characteristics of the soil are determined on the four sides of the repair pit in order to determine the coefficient accounting for the above parameters of the soil, the length of the freezing apparatuses is measured, and the flow rate of liquid nitrogen is determined; wherein the required number of freezing apparatuses is determined from the following dependence:

,

wherein N is the number of freezing apparatuses; k is the coefficient accounting for the hydrophysical parameters of the soil; P is the perimeter of the pit, m; N is the length of the freezing apparatuses, m; q is the standard specific flow rate of the cooling agent, l/m³; Q is the flow rate of liquid nitrogen, l.

EFFECT: reduced labour intensity of work required for the installation of freezing tubes and optimised flow rate of the cryogenic agent ensuring the minimum required thickness of the ice and soil barrier along the entire perimeter of the repair pit.

1 cl, 2 dwg, 1 ex