Device for measuring displacement of soil layers under foundation base

Abstract

FIELD: soil mechanics.SUBSTANCE: invention relates to determining the lower boundary of the compressible layer after loading the foundation (stamp) in order to refine the calculation of foundation settlement. A device for measuring the displacement of soil layers under the base of a foundation includes a guide pipe of variable polygonal cross-section with freely fixed soil marks with helical blades configured to move along the axis of the guide pipe, wherein the diameters of the soil marks are made variable, decreasing from top to bottom, whereas the measuring instruments are installed in a reference system, to which a guide pipe with strings located inside, connecting the measuring instruments and the soil marks, is attached with its upper end using a conductor. The guide pipe is made as a single piece with at least three paired through grooves. The marks are freely secured with removable pins, seated with a gap and allowing movement in paired grooves along the pipe axis. The heights of the grooves are variable, decreasing from top to bottom, and the guide pipe is passed through an opening in the foundation.EFFECT: increasing the reliability of the device’s ability to be used multiple times.1 cl, 4 dwg

Description

[0001] The invention relates to the field of soil mechanics and serves, in particular, to determine the lower boundary of the compressible layer after loading the foundation (stamp), in order to clarify the calculation of the foundation settlement.

[0002] A device for measuring soil deformations is known [1], which includes marks located on an elastic (flexible) pipe.

[0003] A device is known for measuring soil deformations by zones in the base of a foundation [2], characterized in that each mark, made in the form of a screw turn, is mounted on separate tubes connected telescopically.

[0004] Known devices [1, 2] for measuring soil deformations by zones in the foundation base have individual operational and design capabilities.

[0005] The prototype of the invention is the closest known device to the proposed design for measuring the displacement of soil layers under the sole of a foundation [3], including a composite guide pipe made of links of variable polygonal cross-section, on each link of which a corresponding mark is freely fixed with the possibility of movement along the axis of the pipe link and the possibility of fixing in a stationary position with the help of a cotter pin, resting against the upper link of a larger cross-section, wherein the diameter of the marks is also made variable, decreasing from top to bottom, while the measuring instruments are installed in a reference system, to which, with the help of a conductor, a guide pipe with strings located inside, connecting the measuring instruments and marks, is attached at its upper end.

[0006] The disadvantages of the technical solution include the low reliability of the possibility of repeated use of the device due to the possibility of losing the lower mark when unscrewing the device, as well as the complexity of its implementation.

[0007] The technical objective of the proposed device for measuring the displacement of soil layers under the foundation sole is to increase the reliability of the device’s repeated use.

[0008] The stated problem is solved in such a way that in a device for measuring the displacement of soil layers, including a guide pipe of a variable polygonal cross-section, with freely fixed soil marks with helical blades with the ability to move along the axis of the guide pipe, wherein the diameters of the soil marks are made variable, decreasing from top to bottom, wherein the measuring instruments are installed in a reference system, to which, with the help of a conductor, the upper end of the guide pipe is attached with strings located inside, connecting the measuring instruments and the soil marks, according to the invention, the guide pipe is made solid with through, at least three paired grooves, the marks are freely fixed with removable pins set with a gap with the ability to move in the paired grooves along the axis of the pipe, wherein the heights of the grooves are made variable, decreasing from top to bottom, and the guide pipe is passed through an opening in the foundation.

[0009] The technical result consists in increasing the reliability of the possibility of repeated use of the device due to the design solution of the guide pipe with paired through grooves and free fastening of marks with removable pins installed with a gap, since when unscrewing the guide pipe with marks for its reuse, not only a torque is applied to the pipe, but also a pulling force, as a result of which there is a possibility of losing the lower mark and moving the upper marks to the links of pipes with smaller cross-sections.

[0010] Information confirming the possibility of implementing the invention with obtaining the above-mentioned technical result is presented by the following drawings, in which:

[0011] Fig. 1 shows a diagram of a device for measuring the displacement of soil layers under the foundation sole;

[0012] Fig. 2 shows section A-A of Fig. 1;

[0013] Fig. 3 shows a diagram of a guide pipe element with a groove and a pin (a pipe with a screw blade in the form of an auger turn, freely placed on the guide pipe, is not shown);

[0014] Fig. 4 shows section B-B of Fig. 3.

[0015] The proposed device consists of a guide tube 1 of a polygonal, for example, square cross-section with through paired grooves 2, on which, at the locations of the paired grooves 2, ground marks 3 are freely fixed with removable pins 4 set with a gap. Guide tube 1 is passed through an opening 5 in the foundation (stamp) and, using a conductor 7, is secured to a reference system 8, where measuring devices 9 are located, connected to the screw marks by strings 10 passing inside guide tube 1.

[0016] The device for measuring layer-by-layer soil displacements operates as follows. Marks 3 are loosely placed on guide pipe 1 at the locations of paired grooves 2 and secured with removable pins 4 set with a gap. Guide pipe 1 is passed through opening 5 in foundation 6. The lowest mark 3 is placed on the ground, removable pin 4 rests against the upper parts of the lower through paired grooves 2. By rotating pipe 1, the lower mark 3 is immersed in the ground. Then, the next mark 3 with pin 4 is raised until pin 4 rests against the upper parts of the next through paired grooves 2. By rotating pipe 1, mark 3 is immersed in the ground. The process is repeated until all marks 3 are immersed to the desired depth. After which, with the help of the conductor 7, the guide pipe 1 is fixed on the reference system 8, where the measuring devices 9 are located, connected to the screw marks by strings 10.When the foundation 6 is loaded, the soil layers in depth undergo displacement, the soil marks 3 with pins 4 also undergo displacement, and the guide pipe 1, secured by the conductor 7 on the reference system 8, remains stationary.

[0017] To reuse the device, the guide pipe with marks is unscrewed from the ground.

[0018] The manufacture of a guide pipe with through paired grooves of a polygonal cross-section allows for the reliable fastening of soil marks with removable pins, eliminating the possibility of losing the lower mark when unscrewing the guide pipe with soil marks, which increases the reliability of the repeated use of the proposed device.

[0019] Sources of information

[0020] 1. Guidelines for monitoring deformations of foundations and bases of buildings and structures / NIIOS im. Gersevanov Gosstroy of the USSR. MSN. 1975, pp. 12-14.

[0021] 2. USSR Author's Certificate No. 573710 IPC G01B 19 / 16 (2000.01), E02D 1 / 00 ​​(2000.01) dated 03.01.1975, published 25.09.1977.

[0022] 3. Russian Federation Patent RU 2657585 C1, IPC E02D 1 / 08 (2006.01) dated 08.08.2017, published 14.06.2018.

Claims

A device for measuring the displacement of soil layers under the sole of a foundation, including a guide pipe of variable polygonal cross-section with freely secured soil marks with helical blades with the ability to move along the axis of the guide pipe, wherein the diameters of the soil marks are made variable, decreasing from top to bottom, wherein the measuring instruments are installed in a reference system, to which, with the help of a conductor, the upper end of the guide pipe is attached with strings located inside, connecting the measuring instruments and the soil marks, characterized in that the guide pipe is made solid with at least three through paired grooves, the marks are freely secured with removable pins, seated with a gap with the ability to move in the paired grooves along the axis of the pipe, wherein the heights of the grooves are made variable, decreasing from top to bottom, and the guide pipe is passed through an opening in the foundation.

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