SU975886A1 - Apparatus for measuring layer-wise deformation of soil - Google Patents

Description

The invention relates to a measurement technique for carrying out in field conditions measurements and observations of layer-by-layer deformations of the soil under the influence of dynamic loads, mainly in difficult hydro-geological operating conditions, for example, in the foundations of hydraulic structures.

A device for measuring layer-by-layer deformations of the soil is known, including marks installed in a well at a certain depth, connected by means of measuring devices mounted on a fixed frame (13.

A disadvantage of this device is that it uses a mechanical connection of elements that perceive displacements at depth, with elements located above the ground surface, and serving to instrumentally determine displacement values.

The closest in technical essence is a device for measuring layer-by-layer deformations of the soil, including brands with end-to-end sliding contacts; measuring wire with high specific electric 2

resistance passed through the sliding contacts and placed together with the marks in the elastic shell

5 ke, filled with liquid agent, measuring devices.

When the position of the mark in the ground changes in relation to the corresponding part of the base of the structure or on the top of the ground, the length of the measuring wire changes on the site of the structure - the ground mark, i.e. there is a change in the electrical resistance of the segment measures-. Noah wire on this site. The measurement of linear displacement is carried out indirectly through changes in the resistances of the sections of the measuring wire G2].

However, the known device, providing accurate measurements of soil deformations under static load, does not allow accurate measurements of deformations under the impact of dynamic loads on the soil, since this device is not able to determine separately the elastic and residual deformations.

The aim of the invention is to provide remote measurement

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975886

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layered deformations of the soil under dynamic loads.

The goal is achieved by the fact that, in a device for measuring layer-by-layer deformations of the soil, including grades with through-sliding contacts, a measuring wire with high specific electrical resistance, passed through sliding contacts and placed together with the marks in an elastic shell filled with a liquid agent, measuring instruments connected to the marks , each brand is made of three parts with through sliding contacts, through which the measured wire is passed, with the middle part of the brand hinged to the elastic th shell, and the extreme, part of the brand is equipped with a brake ohm.

Figure 1 shows the device, a longitudinal section; figure 2 - brand soil, section, figure 3 - brand soil in the process of measuring displacements.

A device for measuring layer-by-layer deformations of the soil contains measures. wire 1, made of a material with high electrical resistance, for example nicrome, 0.2 mm in diameter, passing successively through sliding electrical contacts 2, 3 and 4, mounted on ground stamps, made, for example, of a dielectric material and consisting of three parts: central 5 connected by special telescopic hinges 6.c, hermetic elastic sheath 7, upper part 8 marks with brake 9, lower part 10 marks with brake 11 ..

The measuring wire 1 is attached to the top end of the tip 12 and is connected to the indicator 13, and the bottom end is connected to the load 14. Indicator 13 is connected to the sliding contacts 2 - 4 by means of flexible electrical wires 15 Sealed elastic sheath 7 after installing the device in the well in the soil mass filled with liquid 16.

• The device works as follows.

Under the influence of a dynamic load, there are displacements of the soil, and, consequently, of an elastic shell 7, telescopic hinges 6 and the central part 5 of the mark.

The central part 5 (position 1 марки) moves along the measuring wire 1 the lower part 10 of the mark to a distance equal to the displacement of the soil at the moment of the greatest impact of the load, and the upper part 8 of the mark remains in the same place. Then, after the termination of the load (or its reduction under

the action of elastic forces restores some of the soil deformations (the so-called region of elastic deformations and the central part 5 of the mark moves back to a distance equal to the value of the elastic deformations of the soil ^! 10th mark remains at the extreme

10 lower position and fixes the value of the total total deformation of the soil layer under the action of dynamic loads. Thus, comparing the resistance values of the segments

(5 dimensional wire 1 between its upper end and parts 5, 8 and 10 of the mark before the start of the dynamic load (corresponding position 8, I,

P fig.Z) with resistance values

2θ, the length of the measured wire between its upper end and the parts of the mark, respectively, determines: for part 10 of the mark (position 10, U of Fig. 3), the value of the total deformation for one part of five marks 5 relative to part 8, the value of residual strain and relative to part 10 the value of elastic deformation.

The proposed device makes it possible to obtain a complete picture of the development of deformations in the soil base mass under the influence of dynamic loads, for example, the development of soil deformations when the mass is compacted using explosion energy, without direct access to the measurement site.

Claims (1)

Claim A device for measuring layer 40 soil deformations, including grades with through sliding contacts, measuring wire with high electrical resistivity, passed through sliding contacts 45 and placed along with the stamps in elastic shells filled with a liquid agent, measuring instruments connected with marks, are distinguished by the fact that, in order to ensure the remote measurement of layer-by-layer deformations of the soil under dynamic loads, each brand is made of three parts having through sliding contacts through which the measured wire is passed, the middle part of the mark is hinged to the elastic sheath, and the extreme marks of the c. are equipped with a brake.