RU2547099C2 - Method of determination of gravitational pressure in massif of connected material medium - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of material interaction physics, namely to the method of determination of gravitational (local) pressure in the massif of connected material medium. The value of gravitational pressure is determined by the relation p_l=(γ·h-c_str)ctgφ_str, where γ - specific gravity of the material medium, h - depth of determination of pressure in the medium massif, c_str - structural specific cohesion of the medium, φ_str - angle of internal friction of the structured medium in a natural occurrence.

EFFECT: improvement of accuracy of determination of local pressure value.

1 dwg

Description

The invention relates to the physics of contact interaction of particles of a coherent material medium in an array of half-space under conditions of gravitational impact.

There is a method of determining natural gravitational (household) pressure in an array of liquid and gas incoherent material medium, which consists in determining the depth h of measuring pressure from the surface of a half-space with density ρ and specific gravity γ = ρ · g, where g is the acceleration of gravity bodies under gravity, and gravitational natural pressure is determined by the calculated dependence p _b = γ · h [1].

Natural pressure p _b = γ · h for incoherent material media (gas, water) in the absence of friction is comprehensive under their surface in half-space and normally acts on the surfaces of objects immersed in them. The value of the tangential stress τ and normal pressure p _b at a given depth are equal to each other τ = p _b = γh.

There is a method of determining the gravitational pressure of a disconnected material medium, which consists in determining the depth h of measuring pressure from the surface of a half-space with a density ρ and specific gravity γ = ρ · g, where g is the acceleration of gravity of a material body under gravity, take the angle of internal friction of an ideally pure material medium φ = 45 ° with an internal friction coefficient f = tgφ = 1, and specific adhesion c≈0, the tangential stress is calculated according to Coulomb's law as τ = p · tgφ + c = p, and gravitational pressure is determined ute, as well as the tangential p _b = τ = γ · h [2].

The technical result according to the method for determining gravitational pressure in an array of a coherent material medium, which consists in setting the depth h of pressure measurement from the surface of the array, determining the tangential stress at a depth h from the dependence τ = ρ · g · h = γ · h, MPa, where ρ is the density, kg / m ³ , γ is the specific gravity of the material medium taking into account the weighing force of water, kg / m ³ , g is the acceleration of gravity of the body under gravity, m / s ² , specific structural adhesion c _pp , MPa, and angle φ _{p of} internal friction of the medium is achieved by о normal gravitational pressure at a depth h of an array of a coherent material medium is determined by calculation using the dependence p _b = (τ-c _p ) ctgφ _p = (γ · hc _p ) ctgφ _p , MPa, and a connected material medium at a depth h <c _p / γ is assumed to be in a vertically stretched tensile state and balanced by atmospheric pressure.

The magnitude of the normal gravitational pressure p _b at a depth h from the surface of a structurally stable connected material half-space is illustrated graphically in FIG. 1 through the Coulomb dependence τ = p _b · tgφ + c _p for extremely loaded soil environment.

The proposed method for determining gravitational pressure in an unirrigated array of a coherent material medium is implemented as follows.

In the process of engineering surveys of the massif of the medium, the depth h (cm) of its study is determined, from which samples with an undisturbed structure are taken. In the laboratory, the specific gravity γ = ρ · g (kg / cm ³ ) is determined from the samples of the medium, where ρ (kg / cm ³ ) is the density of the medium, g (m / s ² ) is the acceleration of gravity of the body, and the tangential voltage at a depth h (cm) of the studied array according to the dependence τ = ρ · g · h = γ · h, suitable for a connected and disconnected material environment. According to the results of laboratory tests of medium samples in shear devices or in stabilometers, a graph of the dependence τ = p · tgφ _p + c _p (kg / cm ² ) of the Coulomb-Mohr limit state of the material medium is established and the values of its strength parameters are determined - the angle φ _{p of} internal friction and c _p (ct / cm ² ) of specific adhesion at at least three steps of increasing compressive pressure ρ (kg / cm ² ) (Fig. 1). The graph τ = p · tgφ _p + c _p determines the value p = p _b = (τ-c _p ) ctgφ _p = (γ · hc _p ) ctgφ _p (kg / cm ² ), which corresponds to the gravitational pressure in the massif of the medium at a depth research h.

At a depth h <c _p / γ, the surface of the earth's crust is in a state of tension and

kept from separating into outer space by atmospheric pressure. At a depth of h = c _p / γ, there is no natural (domestic) pressure in the soil mass.

Gravitational pressure appears at a depth h> c _p / γ from the earth's surface.

Example 1. Archaeological excavations of preserved historical values in a cohesive soil environment with specific adhesion c _p = 0.02 MPa; specific gravity γ _p = 0.0019 kg / cm ² should be made from depth h = c _p / γ _p = 1.05 m. If burials were made at a depth of h <1.05 m, then over the years on the surface of the soil medium tomb crosses will be supplanted, which is marked today as “a miracle” by believers and has not yet been explained by scientists.

. При σ_пл=0,00739 кг/м, γ_в=981 кг/м³ получаем h_пл=27,978·10^-4 м, а удельное сцепление воды c_в=τ_в=γ_в·h_пл=274,642·10^-6 кг/см²=27,446 Па.Example 2. Water in its pure form has a surface tension of the upper layer - film σ _PL = P / l, determined by the force P applied to the metric unit of the rectilinear section of the water surface boundary in the direction tangent to the liquid surface at its equilibrium. At a temperature of Τ = 20 ° C, the surface tension σ _PL = 0.0725 j / m ² = 0.0725 N / m ≈ 0.00739 kg / m. With the acceleration of gravity g = 9.81 m / s ² and the density of pure water ρ = 1000 kg / m ^{3, the} specific gravity of water is γ = 981 kg / m ³ . The specific adhesion of the surface film of water with a thickness of h _pl and water as a whole is c _in = ρ _in · g · h _pl = γ _in · h _pl = τ _in = σ _pl / h _pl , where τ _in is the tangential (tangential) stress. The thickness of the film of water in a state of surface tension,

. When σ _mp = 0.00739 kg / m, γ _a = 981 kg / m ^3, we obtain h _mp = 27.978 · 10 ^-4 m, and specific cohesion _in water c = τ _a = γ · h _at 274.642 · _mp = 10 ^{- 6} kg / cm ² = 27.446 Pa.

The surface tension coefficient of the water surface at a given temperature is α = σ _PL = τ _in · h _PL = c _in h _PL = γ _in h ² _PL = 981 kg / m ³ (27.978 · 10 ^-4 m) ² = 76.79 · 10 ^-4 kg / m = 75.33 · 10 ^-3 N / m. At T = 0 ° C, the experimental coefficient of surface tension of water is α = σ _PL = 75.6 · 10 ^-3 N / m [4].

Information sources

1. Landsberg G.A. Elementary textbook of physics / mechanics. Heat. Molecular physics. - T.1, edition 8. - M .: "Science". - S. 122, 323-327.

2. Tsytovich N.A. Soil mechanics / Short course: Publishing house 3, add. - M .: "Science", 1979. - S. 46-47.

3. Landsberg G.A. Elementary textbook of physics / mechanics. Heat. Molecular physics. - T.1, edition 8. - M .: "Science". - S. 509-513.

4. Koshkin N.I., Shirkevich M.G. Handbook of Elementary Physics / Publishing House 5, revised. and add. - “Science”, 1972. - P.84.

Claims (1)

The method for determining gravitational pressure in an array of a connected material medium, which consists in setting the depth h of pressure measurement from the surface of an array of medium, determining the tangential stress τ = ρ · g · h = γ · h, MPa at a depth h, where the specific gravity γ = ρ · g, kg / m ³ , of the medium itself, where ρ is the density of the medium, kg / m ³ , g is the acceleration of gravity, m / s ² , specific structural cohesion c _pp , MPa, and the angle φ _{str of} internal friction of the medium, characterized in that the normal gravitational pressure at a depth h of an array of a connected material medium is determined divide by calculation according to the dependence p _b = (γ · hc _pp ) ctgφ _pp , MPa, and a connected material medium at a depth of h <c _p / γ is taken to be in a vertically stretched tensile state and balanced by atmospheric pressure.