SU977568A1 - Pressiometer - Google Patents

Description

(54) PRESSIOMETER

The invention relates to the construction, in particular to engineering geological research.

A pressiometer is known, comprising a housing with an elastic sheath and a measuring device consisting of an inductive converter and a unit, recording 1.

Closest to the present invention is a pressiometer comprising a housing with an elastic shell and a measuring device made in the form of a chamber, the lower part of which is equipped with spring-loaded plungers and filled with mercury, and the upper part is equipped with a rheostat and elastic diaphragm and filled with a dielectric liquid 2.

A disadvantage of the known devices lies in the low accuracy of research, due to the inability to take into account the deformation of the elastic shell over its entire surface.

The purpose of the invention is to improve the accuracy of research.

The goal is achieved by the fact that in a pressiometer that includes a housing with an elastic shell and a measuring device made in the form of a chamber, the lower part of which

equipped with spring-loaded plungers and filled with mercury, while the top one is equipped with a rheostat and an elastic diaphragm and filled with a dielectric fluid, the measuring device is equipped with an additional chamber with plungers, a rheostat, a mercury and a dielectric fluid installed inside the chamber.

ten

Additional chamber plungers are displaced relative to the Kame3 loO plungers

angles 0 /. where y is a number

plungers in one chamber.

15

Chambers have equal cross-sectional areas.

The chamber resistors have the same resistance.

FIG. 1 shows a pressure meter,

20 longitudinal section; in fig. 2 is a section A-A in FIG. If in FIG. 3 is a section BB in FIG. one.

Claims (2)

The pressiometer includes a housing 1 with 25 elastic sheath 2, a pipeline 3 and a cable 4, a measuring device, which is a mercury-rheostat sensor, consisting of two concentrically arranged chambers 5 and 6, 30 whose lower cavities are filled with mercury (for example alcohol). At the bottom of the chamber Xc1, the plungers 7 and 8 are installed with a uniform angular displacement, unclenched by springs 9 and 10 until they stop into the shell 2. The chambers contain rheostats made in the form of coils 11 and 12 of thin steel wire with a large (2-3 mm) gap between turns. The lower turns of the spirals 11 and 12, located in mercury, are closed on the body. The upper coils of the spirals 11 and 12 and the housing 1 are connected to two microammeters (not shown). The outer chamber 6 is covered by a rubber diaphragm 13. The pressiometer operates as follows. Before the pressiometer starts operation, the lower cavities of chambers 5 and b are filled with mercury, which closes the lower turns of coils 11 and 12. During loading, plungers 7 and 8, following shell 2 under pressure from springs 9 and 10, move out of chambers 5 and 6. their volume. A corresponding decrease in the level of mercury in chamber 5 and 6 causes an increase in the resistance of coils 11 and 12, recorded by the readings of the microammeters. When the working pressure is relieved, the plungers 7 and 8 return to their initial position due to the elasticity of the shell 2, and the mercury refills chambers 5 and 6. During the tests, the pressure in the space between the casing and the elastic shell 2 rises until the deformation readings are completely stabilized. The presence of two chambers, the plungers of which are located in different vertical (with an angular displacement of i -360 / 2i, where m is the number of plungers in one chamber) and horizontal planes, it is possible to determine the soil deformations in a large number of measurement points, which increases the accuracy of research. Claim 1. Presciometer, comprising a housing with an elastic shell and a measuring device made in the form of a chamber, the lower part of which is equipped with spring-loaded plungers and filled with mercury, and the upper part is equipped with a rheostat and an elastic diaphragm and filled with a dielectric fluid, characterized in that In order to improve the accuracy of research, the measuring device is equipped with an additional chamber installed concentrically inside the chamber with plungers, a rheostat, mercury and a dielectric fluid. 2.Pressiometer according to claim 1, which is based on the fact that the plungers of the additional chamber are displaced relative to the plungers of the chamber by the angle H. g360 / 2I, where Y is the number of plungers in one chamber. 3. The pressometer according to claim 1, wherein the chambers have equal cross-sectional areas. 4. The pressure tester according to claim 1, wherein the chamber rheostats have the same resistance. Sources of information taken into account during the examination 1. USSR author's certificate No. 586358, cl. E 02 L 1/00, 1977. 2. Authors certificate of the USSR 402799, cl. G 01 N 33/24, 1973.