METHOD FOR STRENGTHENING STRUCTURALLY UNSTABLE SOILS WITH KARST FORMATIONS AND/OR WATER-SATURATED SOILS USING MICROPILES AND INJECTORS FOR FORMING MICROPILES Russian patent published in 2023 - IPC E02D3/12 

FIELD: construction.

SUBSTANCE: invention relates to the field of construction, in particular, to methods for improving soils by strengthening them by introducing hardening or pore-filling substances into the soil that ensure the drainage of groundwater, and can be used, in particular, in technologies for strengthening structurally unstable soils in preparing sites for the construction of new structures or when strengthening soils under the foundations and bases of the existing ones. A method for strengthening structurally unstable soils with karst formations and/or water-saturated soils by means of micropiles includes drilling wells with the formation of a barrier row and wells in the main mass, in which the wells are arranged along a grid, the dimensions of which are determined by the project and depend on the composition and properties of soils, installation in wells injectors of different heights, having a perforated part and not removed from the soil at the end of the process of strengthening the geomassif, injection of an injection cement mortar into the soil, starting from wells in the barrier row. In the barrier row, the wells are arranged in at least two rows in a checkerboard pattern, and the injection of cement mortar into the soil in the wells of the barrier row is carried out simultaneously in one or in different horizons at design pressures lower than the hydraulic fracturing pressure of soils, and with a directional supply of cement mortar into borehole walls inside the barrier row. Injection of cement mortar in the wells of the main massif is carried out in different order and in different geological sections of the soil of the reinforced massif, taking into account their properties determined in accordance with the project, and with a gradual increase in the cement mortar supply pressure, forming oriented micropiles from the supplied cement mortar based on non-recoverable injectors. At the initial stage of injecting the wells of the barrier row and the main massif, the wells are plugged, dividing them into horizons in accordance with the sequence of injection established by the project, and the increase in the cement mortar supply pressure in the wells of the main massif is limited by the pressure of hydraulic fracturing of soils in the geological sections being strengthened.

EFFECT: ensuring the reliability of the prepared geomassifs for the construction of new facilities and for strengthening the sites under the existing buildings.

5 cl, 3 dwg