Soil dynamic strain testing device

Abstract

The present invention provides a soil dynamic strain testing device, which belongs to the field of soil monitoring equipment, including a test column, a pressure plate, a main strain gauge and a temperature compensation strain gauge; the test column is an elastic component; there are two pressure plates, which are respectively fixed at the two ends of the test column, the plate surface of the pressure plate is perpendicular to the long axis of the test column, and the pressure plate and the test column are coaxially arranged; there are four main strain gauges, which are uniformly bonded to the test column around the long axis of the test column, and the four main strain gauges are all located on the same radial surface of the test column; the temperature compensation strain gauge is separated from the test column. The soil dynamic strain testing device provided by the present invention can be buried in a plurality of test areas according to test requirements, and can test dynamic strains at different plane positions and different depths. It is easy to use, and the test results are accurate and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of soil monitoring equipment, and more specifically, relates to a soil dynamic strain testing device. Background Art

[0002] Railway subgrade is generally a soil-rock structure. The connection between soil-rock particles is weak, which makes the soil-rock skeleton structure unstable. When a train passes on the track, dynamic load will be generated. When the dynamic load and deformation are small, the connection between soil-rock particles is almost not destroyed, and the deformation of the soil skeleton can be restored, and the plastic deformation can be ignored; with the increase of dynamic load, the connection between soil-rock particles is gradually destroyed, and the soil skeleton will produce irreversible deformation; when the dynamic load increases to a certain extent, the connection between soil-rock particles is almost completely destroyed. It can be seen that under the action of external load, the subgrade may deform, and in severe cases it may even affect the track of the rails, thereby affecting the safety of train operation. Therefore, monitoring the dynamic strain of the subgrade is one of the factors to ensure the safety of railway operation. However, there is currently a lack of test equipment for monitoring the dynamic strain of the subgrade, which makes dynamic strain monitoring ineffective. Summary of the invention

[0003] The purpose of the present invention is to provide a soil dynamic strain testing device, aiming to solve the technical problem of lack of a testing device for monitoring the dynamic strain of a roadbed.

[0004] To achieve the above object, the technical solution adopted by the present invention is: to provide a soil dynamic strain testing device, comprising:

[0005] The test column is an elastic member;

[0006] There are two pressure plates, which are respectively fixed at two ends of the test column, the plate surface of the pressure plate is perpendicular to the long axis of the test column, and the pressure plate is coaxially arranged with the test column;

[0007] There are four main strain gauges, the four main strain gauges are uniformly bonded to the test column around the long axis of the test column, and the four main strain gauges are located on the same radial surface of the test column; and

[0008] A temperature compensation strain gauge is provided separately from the test column.

[0009] As another embodiment of the present application, a temperature compensation sheet bonding ring is provided on the pressure plate, the temperature compensation sheet bonding ring is arranged around the outer periphery of the test column, and the temperature compensation strain gauge is bonded to the temperature compensation sheet bonding ring.

[0010] As another embodiment of the present application, the test column is a hard plastic column.

[0011] As another embodiment of the present application, the pressure plate is an aluminum alloy plate.

[0012] As another embodiment of the present application, the ratio of the diameter of the pressure plate to the diameter of the test column is greater than 5:1.

[0013] As another embodiment of the present application, the main strain gauge is disposed on an outer side wall of the test column.

[0014] As another embodiment of the present application, the test column is a hollow column, the main strain gauge is arranged on the inner wall of the test column, the end of the test column is provided with an opening connected to the inner cavity of the test column, and the cable connected to the main strain gauge extends along the opening of the test column to the outside of the test column.

[0015] As another embodiment of the present application, a sealing ring is provided at the opening of the test column, which is arranged around the cable and is used to seal the opening.

[0016] As another embodiment of the present application, a threaded hole is provided on the pressure plate, and both ends of the test column are provided with external thread structures for threadably matching with the threaded hole.

[0017] As another embodiment of the present application, a temperature sensor is also provided on the pressure plate.

[0018] The beneficial effect of the soil dynamic strain testing device provided by the present invention is that compared with the prior art, after being buried in the soil, the soil dynamic strain testing device of the present invention bears the pressure of the soil in a certain area at both ends of the test column through the pressure plate, and transmits the pressure to the test column. Since the test column is elastic, it can undergo elastic deformation in its own axial direction after bearing the pressure. The four main strain gauges sense the strain of the test column itself in real time, and transmit the strain signal to the signal processing equipment located outside the roadbed through the cable. Since the four main strain gauges are evenly and symmetrically arranged around the central axis of the test column, the bending correction can be more effectively achieved, and the direction of the extrusion bending can be determined, reducing the influence of uneven deformation; and, through the temperature compensation strain gauge separated from the test column, temperature compensation can be achieved, eliminating the influence of temperature on the dynamic strain test. The soil dynamic strain testing device of the present invention can be buried in a number of test areas according to the test requirements, and can test the dynamic strains of different plane positions and different depths. It is easy to use, and the test results are accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a soil dynamic strain testing device provided in Embodiment 1 of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a soil dynamic strain testing device provided in the second embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the structure of a soil dynamic strain testing device provided in Embodiment 3 of the present invention;

[0023] Figure 4 This is a schematic diagram of the use status of the soil dynamic strain testing device provided in Example 1 of the present invention.

[0024] In the figure: 1. Test column; 2. Pressure plate; 3. Main strain gauge; 4. Temperature compensation strain gauge; 5. Cable; 6. Temperature compensation gauge bonding ring; 7. Blocking ring; 8. Temperature sensor; 9- Signal processing equipment; 10- Roadbed; 11- Limiting protrusion DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] Please also read Figures 1 to 4 , the soil dynamic strain testing device provided by the present invention is now described. The soil dynamic strain testing device comprises a test column 1, a pressure plate 2, a main strain gauge 3 and a temperature compensation strain gauge 4. The test column 1 is an elastic component; there are two pressure plates 2, and the two pressure plates 2 are respectively fixed at the two ends of the test column 1, the disk surface of the pressure plate 2 is perpendicular to the long axis of the test column 1, and the pressure plate 2 is coaxially arranged with the test column 1; there are four main strain gauges 3, and the four main strain gauges 3 are uniformly bonded to the test column 1 around the long axis of the test column 1, and the four main strain gauges 3 are all located on the same radial surface of the test column 1; the temperature compensation strain gauge 4 is separated from the test column 1.

[0027] When burying the test device, the long axis of the test column 1 needs to be parallel to the vertical direction.

[0028] Compared with the prior art, the soil dynamic strain test device provided by the present invention, after being buried in the soil, bears the pressure of the soil in a certain area at both ends of the test column 1 through the pressure plate 2, and transmits the pressure to the test column 1. Since the test column 1 is elastic, it can undergo elastic deformation in its own axial direction after bearing the pressure. The four main strain gauges 3 sense the strain of the test column 1 itself in real time, and transmit the strain signal to the signal processing device 9 arranged outside the roadbed through the cable 5. Since the four main strain gauge rings 3 are evenly and symmetrically arranged around the central axis of the test column 1, the bending correction can be more effectively achieved, and the direction of the extrusion bending can be determined, reducing the influence of uneven deformation; and, through the temperature compensation strain gauge separated from the test column 1, temperature compensation can be achieved, eliminating the influence of temperature on the dynamic strain test. The soil dynamic strain test device of the present invention can be buried in a plurality of them in the test area according to the test requirements, and can test the dynamic strains of different plane positions and different depths. It is easy to use, and the test results are accurate and reliable.

[0029] The strain ε of the test column 1 is Δι / ι, Δι is the axial deformation of the test column 1 , and ι is the original length of the test column 1 .

[0030] Specifically, only one temperature compensation strain gauge 4 may be provided.

[0031] As a specific implementation of the soil dynamic strain testing device provided by the present invention, please refer to Figures 1 to 3 , a temperature compensation sheet bonding ring 6 is provided on the pressure plate 2, and the temperature compensation sheet bonding ring 6 is arranged around the outer periphery of the test column 1, and a temperature compensation strain gauge 4 is bonded to the temperature compensation sheet bonding ring 6. Since the temperature compensation sheet bonding ring 6 is separated from the test column 1, the temperature compensation sheet bonding ring 6 is not easy to deform along with the test column 1 due to pressure, thereby ensuring that the temperature compensation strain gauge 4 is effectively assembled while preventing the temperature compensation strain gauge 4 from being affected by elastic deformation. As a specific implementation of an embodiment of the present invention, the material of the temperature compensation sheet bonding ring 6 is consistent with the material of the test column 1.

[0032] As a specific implementation of the embodiment of the present invention, the test column 1 is a hard plastic column, so that the test column 1 is light in weight and has a certain elasticity.

[0033] Specifically, the test column 1 is a nylon column.

[0034] As a specific implementation of the embodiment of the present invention, the pressure plate 2 is an aluminum alloy plate. The aluminum alloy material is light in weight and high in strength, which can not only effectively withstand the pressure of the soil, but also its own weight will not affect the deformation of the test column 1, thus ensuring the accuracy of the test.

[0035] As a specific implementation of the embodiment of the present invention, the ratio of the diameter of the pressure plate 2 to the diameter of the test column 1 is greater than 5: 1. This ratio setting enables the pressure plate 2 to effectively receive the pressure from the soil, and also enables the test column 1 to undergo effective elastic deformation, thereby ensuring accurate test results.

[0036] Specifically, the diameter of the pressure plate is 100 mm, and the diameter of the test column 1 is less than 20 mm.

[0037] As a specific implementation of the embodiment of the present invention, refer to Figure 1 and Figure 2 , the main strain gauge 3 is arranged on the outer side wall of the test column 1. The main strain gauge 3 is arranged outside the test column 1 for easy installation.

[0038] As a specific implementation of the embodiment of the present invention, refer to Figure 3 The test column 1 is a hollow column, the main strain gauge 3 is arranged on the inner wall of the test column 1, the end of the test column 1 is provided with an opening connected to the inner cavity of the test column 1, and the cable 5 connected to the main strain gauge 3 extends along the opening of the test column 1 to the outside of the test column 1. The main strain gauge 3 is arranged inside the test column 1, is not easily affected by the friction of the soil, is not easily damaged, and has a longer service life.

[0039] As a specific implementation of the embodiment of the present invention, refer to Figure 3 In order to effectively seal the inner cavity of the test column 1 and prevent soil and rock particles from entering the inner cavity, a sealing ring 7 is provided at the opening of the test column 1, which is arranged around the cable 5 and is used to seal the opening.

[0040] As a specific implementation of the embodiment of the present invention, the temperature compensation strain gauge 4 is bonded to the outer ring surface of the temperature compensation gauge bonding ring 6. The top surface or bottom surface of the temperature compensation gauge bonding ring 6 is bonded to the pressure plate 2, and the temperature compensation strain gauge 4 is arranged outside the temperature compensation gauge bonding ring 6 for easy installation.

[0041] Specifically, the temperature compensation sheet bonding ring 6 is bonded to the upper pressure plate 2 or the lower pressure plate 2 .

[0042] As a specific implementation of the embodiment of the present invention, please refer to Figures 1 to 3 The temperature compensation strain gauge 4 is bonded to the inner ring surface of the temperature compensation gauge bonding ring 6. The temperature compensation strain gauge 4 is arranged inside the temperature compensation gauge bonding ring 6, is not easily rubbed by the soil, is not easily damaged, and has a longer service life.

[0043] As a specific implementation of the embodiment of the present invention, refer to Figure 3 and Figure 4The pressure plate 2 is provided with a threaded hole, and both ends of the test column 1 are provided with an external thread structure for threading with the threaded hole. The threaded connection structure is relatively simple to process and assemble, has high connection strength, and reliable performance.

[0044] Specifically, the threaded hole on the pressure plate 2 is a through hole, and a limiting structure for abutting against the end face of the test column 1 is arranged at the outer end of the through hole, or a limiting protrusion 11 for abutting against the inner end face of the threaded hole is arranged on the test column 1 to prevent the test column 1 from being over-screwed and protruding from the pressure plate 2.

[0045] Specifically, the threaded hole on the pressure plate 2 is a blind hole.

[0046] As a specific implementation of the embodiment of the present invention, refer to Figures 2 to 4 The pressure plate 2 is also provided with a temperature sensor 8, which can be provided on the upper pressure plate 2 or on the lower pressure plate 2. The temperature sensor 8 is a platinum resistance temperature sensor.

[0047] As a specific implementation of the embodiment of the present invention, please refer to Figures 1 to 4 The outer diameter of the pressure plate 2 gradually decreases from the direction facing away from the test column 1 to the direction facing the test column 1. Since the pressure plate 2 has a larger surface area facing away from the test column 1, it can more effectively receive the pressure of the soil in the corresponding area.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Soil dynamic strain testing device, characterized in that: include: The test column is an elastic member; There are two pressure plates, which are respectively fixed at the two ends of the test column, the plate surface of the pressure plate is perpendicular to the long axis of the test column, and the pressure plate is coaxially arranged with the test column, and the pressure of the soil in a certain area at the two ends of the test column is borne by the pressure plate; There are four main strain gauges, the four main strain gauges are uniformly bonded to the test column around the long axis of the test column, and the four main strain gauges are located on the same radial surface of the test column; as well as A temperature compensation strain gauge, wherein the temperature compensation strain gauge is separated from the test column; The pressure plate is provided with a temperature compensation sheet bonding ring, the temperature compensation sheet bonding ring is arranged around the outer circumference of the test column, and the temperature compensation strain gauge is bonded to the temperature compensation sheet bonding ring; The test column is a hollow column, the main strain gauge is arranged on the inner wall of the test column, the end of the test column is provided with an opening connected to the inner cavity of the test column, and the cable connected to the main strain gauge extends along the opening of the test column to the outside of the test column.

2. The soil dynamic strain testing device according to claim 1, characterized in that: The test column is a hard plastic column.

3. The soil dynamic strain testing device according to claim 1, characterized in that: The pressure plate is an aluminum alloy plate.

4. The soil dynamic strain testing device according to claim 1, characterized in that: The ratio of the diameter of the pressure plate to the diameter of the test column is greater than 5:

1.

5. The soil dynamic strain testing device according to claim 1, characterized in that: The main strain gauge is arranged on the outer side wall of the test column.

6. The soil dynamic strain testing device according to claim 1, characterized in that: A sealing ring is provided at the opening of the test column, which is arranged around the cable and is used to seal the opening.

7. The soil dynamic strain testing device according to any one of claims 1 to 5, characterized in that: The pressure plate is provided with a threaded hole, and both ends of the test column are provided with external thread structures for threadably matching with the threaded hole.

8. The soil dynamic strain testing device according to any one of claims 1 to 5, characterized in that: The pressure plate is also provided with a temperature sensor.

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