METHOD FOR DETERMINING PARAMETERS OF LONG-TERM STRENGTH OF FROZEN SOILS AT VARIOUS TEMPERATURES UNDER FIELD CONDITIONS AND DEVICE FOR ITS IMPLEMENTATION

摘要

FIELD: construction.;SUBSTANCE: invention relates to the field of construction; it can be used to determine strength parameters of frozen and thawing soils during geo-mechanical surveys for the design and inspection of foundations of various buildings in a cryolite zone. A method for determining parameters of long-term strength of frozen soils at various temperatures under field conditions includes loading a stamp with a maximum value of a compressive load, stepwise loading of the stamp with a tangential shear load for shear deformations close to the limit, further testing in a creep mode - relaxation for stabilization of tangential stresses, subsequent stepwise reducing a vertical compressive load and withstanding a relaxing tangential load in time until its values are stabilized, then decreasing the absolute value of negative temperature, and repeating operations at a new temperature value, determining soil strength parameters for a given value of negative temperature based on obtained pairs of values of stabilized tangential and normal stresses. The loading of an array is carried out on an annular surface by means of an inventory stamp and an annular shape of a sole with radial ribs equipped with temperature sensors and thermal heaters. The contact of the stamp with the ground is created by embedding ribs into the ground. The shear tangential load is created by applying a torque to the stamp through an elastic element. The temperature of the studied soil area is gradually changed in the direction of increasing or decreasing absolute values by changing the surface temperature under the annular sole of the stamp, inside and outside of it, measuring a temperature value in a shear plane under lower edges of stamp ribs. ;EFFECT: providing the possibility to determine, based on the results of one test, parameters of long-term strength of frozen soil in the field at various values of negative temperatures and during thawing, while reducing the complexity of preparatory work, testing time, and improving the accuracy of tests.;5 cl, 4 dwg