A test device for simulating underground road defects

Abstract

This invention discloses a test device for simulating underground road defects, comprising a simulation chamber, airbags, and an air pump. The simulation chamber is a hollow box with an inlet and an outlet for water, allowing control of the water flow rate. Several airbags are placed inside the simulation chamber, and the space outside the airbags is filled with manufactured sand. The air pump is connected to the airbags and is used to inflate or deflate them. This invention can simultaneously simulate one or more underground defects in a closed environment, enabling comparative tests to verify the technical capabilities of various testing institutions.

Description

Technical Field

[0001] This invention relates to the field of underground disease simulation technology, and in particular to a test device for simulating underground road diseases. Background Technology

[0002] Underground defects refer to undesirable geological formations that exist below the ground surface, such as cavities, voids, loose bodies, and water-rich bodies, which threaten urban safety. Voids refer to cavities of a certain size that develop between the surface crust and the foundation soil; cavities refer to naturally developed or artificially formed cavities of a certain size in the underground soil; loose bodies refer to undesirable geological formations with a density significantly lower than the surrounding soil; and water-rich bodies refer to undesirable geological formations with a water content significantly higher than the surrounding soil.

[0003] The specific characteristics of each type of disease are as follows: Voids are located between the hard crust layer and the foundation soil, with shallow burial depth. Cavities are located in the foundation soil, varying in size, and their upper and lower interfaces are generally uneven, posing a risk of instability to the superstructure or upper soil. Loose bodies, relative to the surrounding soil, are characterized by uneven structure, looseness, low density, low strength, and high compressibility; strength decreases as the looseness of the loose body increases; as the loose body gradually expands to a certain extent, its own bearing capacity decreases, the internal soil collapses, and cavities develop on top of the loose body, resulting in voids between the subgrade and base course, and between the base course and surface course. Water-rich bodies, relative to the surrounding soil, have poor uniformity, high water content, are in a fluid plastic state, are highly sensitive, have very low strength, large porosity, and high compressibility; due to local hydraulic action, the soil structure in water-rich areas weakens, strength decreases, and engineering properties deteriorate, endangering the safety of surrounding projects, and cavities develop on top of them.

[0004] Ground-penetrating radar (GPR), a relatively mature technology in urban road applications in recent years, features high efficiency, anti-interference capabilities, high accuracy, and convenient on-site operation. Domestic and international engineering practices have shown that GPR has become the preferred technical means for the general survey and detection of hidden defects beneath roads, suitable for detecting various road subsidence hazards such as cavities, structural layer voids, loose soil, and water-rich areas.

[0005] Ground-penetrating radar (GPR) is an electromagnetic detection technology that uses electromagnetic waves to detect the distribution of underground media in order to determine their internal structure. Its working principle is as follows: The GPR transmitter emits electromagnetic waves into the ground through a transmitting antenna. Echoes are generated at points of discontinuity in the medium. These echo signals are received by the receiving antenna and sent to the receiver for sampling. The sampled data undergoes various processing steps and is then displayed. When electromagnetic waves propagate through a medium, their propagation characteristics vary depending on the electrical parameters and geometry of the medium. By transmitting high-frequency broadband electromagnetic waves, the receiving antenna receives echoes from the ground (these echoes may be reflected waves from underground interfaces, scattered waves from underground anomalies, or transmitted waves that reach the receiving antenna through a specific path). Based on information such as the two-way travel time, amplitude variations, frequency differences, and phase differences of the received echoes, the system processes and analyzes the data to extract target physical properties and geometric information, create images, and infer the structural morphology or changes in physical properties of the underground medium.

[0006] To determine the capability of testing institutions in using ground-penetrating radar to detect underground defects and the reliability of their test data, comparative testing is necessary to assess the technical level of the testing institutions. Comparative testing refers to the organization, implementation, and evaluation of multiple laboratories testing the same test item (called a "proficiency testing item") under pre-defined conditions. Comparative testing is a form of laboratory proficiency testing; it evaluates whether a testing institution is competent to perform its testing work and whether the data it produces is reliable and valid. It is also one of the technical means used by metrology certification bodies and regulatory agencies to determine laboratory capabilities.

[0007] Ground-penetrating radar (GPR) detects underground defects, which are inherently concealed. Currently, due to the lack of suitable capability verification materials, comparative tests of GPR detection of underground defects have not been effectively conducted in China. Therefore, creating a new testing device to simulate underground road defects is one of the important research and development topics at present. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a test device for simulating underground road defects, which can simultaneously simulate one or more of the following underground defects: voids, cavities, loose bodies, and water-rich bodies, and conduct the simulation in a closed environment. This allows for comparative verification of the technical level of testing institutions, thereby overcoming the shortcomings of existing underground defect simulation devices.

[0009] To solve the above-mentioned technical problems, the present invention provides a test device for simulating underground road defects, characterized in that it includes a simulation box, airbags and an air pump. The simulation box is a hollow box with a water inlet and a water outlet, and the flow rate of water injection or drainage can be controlled. Several airbags are placed inside the simulation box, and the space outside the airbags inside the simulation box is filled with manufactured sand. The air pump is connected to the airbags and is used to inflate or deflate the airbags.

[0010] As an improvement of the present invention, the number of airbags is two, namely a first airbag and a second airbag, wherein the volume of the first airbag is larger than that of the second airbag.

[0011] Furthermore, the first airbag and the second airbag are each connected to a separate air pump, allowing for independent control of inflation or deflation.

[0012] Furthermore, the first airbag is located in the middle of the simulation chamber, and the second airbag is located directly below the first airbag.

[0013] Furthermore, the simulation chamber is equipped with a cover to seal the simulation chamber.

[0014] Furthermore, the water inlet and the water outlet are respectively located on the left and right side walls of the simulation tank.

[0015] Furthermore, the height of the water inlet is higher than the height of the water outlet.

[0016] With this design, the present invention has at least the following advantages:

[0017] 1. Simulating underground disease structures in a closed environment serves as a comparative verification of the technical capabilities of testing institutions.

[0018] 2. It can simultaneously simulate one or more underground diseases such as voids, cavities, loose bodies, and water-rich bodies, making the verification results more accurate. Attached Figure Description

[0019] The above is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 This is a schematic diagram of the structure of an experimental device for simulating underground road defects provided by the present invention.

[0021] Explanation of reference numerals in the attached diagram: 1-First airbag; 2-Second airbag; 3-Air pump; 4-Simulation box; 5-Cover plate; 6-Water inlet; 7-Drain outlet. Detailed Implementation

[0022] Please see Figure 1The present invention provides a test device for simulating underground road defects, including an airbag, an air pump 3, a simulation box 4 and a cover plate 5.

[0023] The simulation box 4 is a hollow box with an internal storage space. The upper opening of the simulation box 4 is closed by a cover plate 5. A drain outlet 7 is provided on the left side wall of the simulation box 4, and a water inlet 6 is provided on the right side wall. Water can be injected into the simulation box 4 or drained out through the water inlet 6 and the drain outlet 7, and the flow rate of water injection and drainage can be adjusted.

[0024] Preferably, the height of the water inlet 6 is higher than the height of the drain outlet 7.

[0025] The airbags are located inside the simulation chamber 4. In this embodiment, there are two airbags, namely the first airbag 1 and the second airbag 2. The first airbag 1 and the second airbag 2 are each connected to an independent air pump 3, which can independently control inflation or deflation. The first airbag 1 is located in the middle of the simulation chamber 4, and the second airbag 2 is located directly below the first airbag 1.

[0026] Inside the simulation chamber 4, the space outside the first airbag 1 and the second airbag 2 is filled with manufactured sand.

[0027] In use, this invention can simulate a water-rich body by adjusting the flow rate and on / off state of the inlet 6 and outlet 7; inflating the first and second airbags 2 can simulate cavities; deflating the second airbag 2 can simulate a loose body in the area between the first and second airbags 1 and 2; and deflating the first airbag 1 can simulate voids under the cover plate 5. Ground-penetrating radars from different testing units sequentially detect the four simulated underground defects according to a pre-established comparative test method, and the comparative test results are generated after statistical analysis. The cover plate 5 acts as a sealed enclosure for the simulation chamber 4, ensuring that the simulation and testing are conducted in a shielded state, thus verifying the technical level of the testing institutions.

[0028] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, or alterations made by those skilled in the art using the disclosed technical content shall fall within the protection scope of the present invention.

Claims

1. A test device for simulating underground road defects, characterized in that, The device includes a simulation box, airbags, and an air pump. The simulation box is a hollow box with an inlet and a outlet for water, and the flow rate of water injection or drainage can be controlled. Several airbags are placed inside the simulation box, and the space outside the airbags inside the simulation box is filled with manufactured sand. The air pump is connected to the airbags and is used to inflate or deflate the airbags. The number of airbags is two, namely a first airbag and a second airbag, and the volume of the first airbag is larger than that of the second airbag. The first airbag is located in the middle of the simulation chamber, and the second airbag is located directly below the first airbag; Adjusting the flow rate and on / off status of the inlet and outlet simulates a water-rich body; filling the first and second airbags with air simulates cavities; filling the first airbag with air and deflating the second airbag can simulate a loose body in the area between the first and second airbags; deflating the first airbag and filling the second airbag with air can simulate delamination.

2. The experimental device for simulating underground road defects according to claim 1, characterized in that, The first airbag and the second airbag are each connected to a separate air pump, and inflation or deflation is controlled independently.

3. The experimental device for simulating underground road defects according to claim 1, characterized in that, The simulation chamber is equipped with a cover to seal it.

4. The experimental device for simulating underground road defects according to claim 1, characterized in that, The water inlet and outlet are respectively located on the left and right side walls of the simulation tank.

5. The experimental device for simulating underground road defects according to claim 1, characterized in that, The height of the water inlet is higher than the height of the water outlet.

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