METHOD FOR DETERMINING MARGINAL STABILITY OF SNOW COVER AT AVALANCHE-PRONE SLOPE Russian patent published in 2018 - IPC E01F7/04 G01N3/34 

FIELD: measuring equipment.

SUBSTANCE: according to the proposed method, a pit is laid in a safe place representative of the controlled avalanche catchment on the avalanche-prone slope. Then the angle of the slope (α) is determined at the pit laying point and layer-by-layer measurements of the volumetric weight (γ_i), the thickness of the layer (h_i) and instantaneous tensile strength (σ_i) for each i-th layer of snow in the pit are carried out. After this, the pressure of the overlying layers (m) is determined for each i-th layer by the formula , after which the marginal stability of the snow cover (n_i) on the avalanche-prone slope is determined according to the formula n_i=σ_i/P_i. When determining the instantaneous snow tensile strength (σ_i), preliminary, using a prismatic snow intake equipped with a circular hole in the upper plane, a sample of snow is cut from each i-th layer of the snow pit. Then a cylindrical sleeve is mounted in the snow intake hole perpendicular to its upper plane, when the cylindrical sleeve is rotated around an axis, it is introducted in the snow intake cavity with snow and pushed down to its lower base. Then a load disk is installed in the cylindrical sleeve and uniaxial impulse compression of the sample in the sleeve is performed until its brittle fracture. The sample fracture force (P_i) and the instantaneous snow tensile strength (σ_i) for each i-th layer are measured. Then a layer of snow in the pit with the smallest marginal stability is identified, by which the stability of the snow cover on the avalanche-prone slope is judged.

EFFECT: increased accuracy of determining the marginal stability of the snow cover.

3 cl, 1 dwg