METHOD FOR REDUCTION OF ACTION OF FORCES OF FROST BOIL AND INCREASING STABILITY OF PILE FOUNDATIONS IN PERMAFROST ZONE Russian patent published in 2016 - IPC E02D27/35 

FIELD: construction.

SUBSTANCE: invention relates to designing, construction and operation of structures in conditions of permafrost zone, particularly, to protection of buildings and structures of frost boil in areas seasonal frost penetrated soils. Method for reduction of action of forces of frost boil and increasing stability of pile foundations in permafrost zone involves immersing piles in permafrost. Method includes determining based on results of preliminary geothermal observations potential areas of occurrence of excess cryogenic heads near pile foundation and in perched water of supra-permafrost aquifer, in limited hydrodynamic zones, placing in said sections water reducing wells with perforated wall in lower part of its forming, immersed at a depth not above roof of permafrost rock. In said wells, installing hydrogeological discharge tubes, in each up to four pieces. Inner space of each of said hydrogeological water discharge tubes in beginning of period of freezing seasonally thawing layer is left free and tightly plugged from lower end of packer, and on top of sealed cover. Inner space of each hydrogeological discharge tube at beginning of period freezing seasonally thawing layer remains free and tightly plugged, and during formation of limited hydrodynamic zones in supra-permafrost aquifer, including perched water, and growth of cryogenic pressure in conditions of passage of depth of soil mass front freezing is performed step-by-step unloading cryogenic pressure, by varying hydrodynamic parameters of “soil foundation” by successive opening of unloading hydrogeological tubes at moments, determined based on analysis results of current geotemperature data, obtained during geotemperature control and monitoring of state of soil mass from beginning of transition period of average daily temperatures of ambient air below 0 °C.

EFFECT: technical result consists in reduction of action of forces of frost boil on pile foundations, higher stability and reduced risk of formation near them of frost mounts in permafrost zone.

1 cl, 4 dwg, 1 tbl