Test device for simulating underground cavity

Abstract

The utility model relates to a test device for simulating an underground cavity, which comprises an underground cavity simulation main body and a structural steel upper cover matched with the underground cavity simulation main body, the structural steel upper cover is connected with a traction device, and the structural steel upper cover moves up and down along the underground cavity simulation main body through the traction device so as to adjust the size of the simulation cavity; the traction device comprises a traction driving main machine and a counterweight device, and the counterweight device is connected with the structural steel upper cover through a traction steel wire rope; and the distributed optical fiber sensors are laid above the underground cavity simulation main body in parallel. In the implementation process, the traction device is used for dragging the structural steel upper cover to move up and down along the underground cavity simulation main body, so that the size of the simulation cavity is adjusted, and then the distributed optical fiber sensors laid above the simulation cavity are used for collecting signals. And meanwhile, the detection accuracy of the distributed optical fiber sensor and the algorithm on underground cavities with different sizes can be further detected.

Description

Technical Field

[0001] This utility model relates to the technical field of distributed optical fiber sensor testing, specifically a test device for simulating underground cavities. Background Technology

[0002] Due to the common problems of underground cavities, such as large burial depth, complex spatial forms, inaccessibility to personnel and measuring equipment, and high safety risks, conventional manual engineering surveys are impossible, resulting in significant limitations in detection. Furthermore, current technologies cannot effectively collect and analyze geophysical data for underground cavities of different sizes. Therefore, the accuracy of existing distributed fiber optic sensors and algorithms for detecting underground cavities of varying sizes cannot be effectively calibrated.

[0003] Therefore, there is an urgent need for an experimental device to simulate the acquisition of geophysical signals from underground cavities of different sizes, so as to provide technical support for the detection and identification of urban underground cavity disasters. Summary of the Invention

[0004] The purpose of this invention is to provide an improved experimental device for simulating underground cavities. Through structural improvements, it supports distributed fiber optic sensors to simulate the acquisition of geophysical signals from underground cavities of different sizes, and to calibrate and test the accuracy of the distributed fiber optic sensors and algorithms in detecting underground cavities of different sizes.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows: A test device for simulating underground cavities, characterized in that: the test device includes an underground cavity simulation body and a structural steel cover that cooperates with the underground cavity simulation body; the structural steel cover is connected to a traction device; the structural steel cover moves up and down along the underground cavity simulation body through the traction device to adjust the size of the simulated cavity; the traction device includes a traction drive host and a counterweight device; the counterweight device is connected to the structural steel cover through a traction steel wire rope; hooks are arranged around the perimeter and center of the structural steel cover; distributed fiber optic sensors are laid parallel above the underground cavity simulation body.

[0006] Preferably, the traction device further includes two traction guide pulleys, which are respectively located on both sides of the traction drive host. The traction wire rope is driven to move by the traction drive host and is wound around the two traction guide pulleys.

[0007] Furthermore, the counterweight device includes a counterweight guide rail and a counterweight that cooperates with the counterweight guide rail.

[0008] Furthermore, the underground cavity simulation body is a hollow rectangular wooden structure with an insect-proof and moisture-proof coating on the inner wall.

[0009] Furthermore, the top of the structural steel cover is equipped with 6-10 branch traction steel wire ropes evenly distributed around the perimeter of the structural steel cover, so that the structural steel cover maintains force balance during the up and down movement. The branch traction steel wire ropes are then combined and connected to the traction steel wire rope.

[0010] Furthermore, the distributed optical fiber sensors are vertically laid above the underground cavity simulation body, with a burial depth of 0.3-1m, and the horizontal distance between the distributed optical fiber sensors and the underground cavity simulation body is 0.3-1m.

[0011] Furthermore, a filling layer is provided above the structural steel cover. The filling layer is a soil layer or a sand and gravel layer, and the filling layer is flush with the surrounding ground.

[0012] Compared with the prior art, the technical solution of this utility model not only improves the overall technical solution, but also includes many detailed improvements. Specifically, it has the following beneficial effects:

[0013] The improved scheme of this utility model includes an experimental device comprising a simulated underground cavity and a structural steel cover that cooperates with the simulated underground cavity. The structural steel cover is connected to a traction device, which moves up and down along the simulated underground cavity via the traction device to adjust the size of the simulated cavity. Distributed fiber optic sensors are laid parallel above the simulated underground cavity, which can simulate and adjust the size of the underground cavity. This facilitates the collection of geophysical signals from underground cavities of different sizes by the distributed fiber optic sensors, and allows for calibration and testing of the accuracy of the distributed fiber optic sensors and algorithms in detecting underground cavities of different sizes.

[0014] In the technical solution of this utility model, the traction device includes a traction drive host and a counterweight device. The counterweight device is connected to the structural steel cover by a traction steel wire rope, which can ensure that the structural steel cover maintains stability and operability when moving up and down along the underground cavity simulation body, and facilitates quick adjustment of the size of the simulated cavity so as to conduct tests on cavities of different specifications.

[0015] In the structure of this utility model, the underground cavity simulation body is a hollow rectangular wooden structure with an insect-proof and moisture-proof coating on the inner wall, which helps the simulated cavity maintain the stability of the structure, making it less prone to deformation and cracking, and ensuring the accuracy of subsequent data reading.

[0016] This utility model has a simple structure, reasonable layout, is easy to use, has good operability, and is easy to promote and utilize. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the structure of the underground cavity simulation body of this utility model.

[0019] Figure 3 This invention provides a geological imaging map of the location of a simulated underground cavity using distributed optical fiber.

[0020] Figure label:

[0021] 1-Traction guide pulley, 2-Traction steel wire rope, 3-Distributed fiber optic sensor, 4-Filling layer, 5-Branch traction steel wire rope, 6-Structural steel cover, 7-Underground cavity simulation body, 8-Counterweight guide rail, 9-Counterweight, 10-Traction drive host, 11-Insect-proof and moisture-proof coating. Detailed Implementation

[0022] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] This invention provides an experimental device for simulating underground cavities, see details below. Figure 1 The difference between this and existing technologies lies in the following: the experimental device includes an underground cavity simulation body 7 and a structural steel cover 6 that cooperates with the underground cavity simulation body. The structural steel cover is connected to a traction device, and the structural steel cover can move up and down along the underground cavity simulation body through the traction of the traction device to adjust the size of the simulated cavity. The traction device includes a traction drive host 10 and a counterweight device. The counterweight device is connected to the structural steel cover through a traction steel wire rope 2. Hooks are arranged around the perimeter and center of the structural steel cover. The traction drive host can drive the traction steel wire rope to move, thereby pulling the structural steel cover up and down. Distributed fiber optic sensors 3 are laid parallel above the underground cavity simulation body to perform signal acquisition.

[0024] During implementation, a traction device is used to move the structural steel cover up and down along the simulated underground cavity, thereby adjusting the size of the cavity. Signals are then collected by distributed fiber optic sensors laid above the cavity. This allows for further testing of the accuracy of the distributed fiber optic sensors and algorithms in detecting underground cavities of different sizes. Signal acquisition and analysis facilitate rapid and accurate early warning and location of large cavities on busy urban roads in subsequent applications. Combined with distributed fiber optic acoustic sensors, communication optical cables can be used to efficiently conduct high-precision detection, monitoring, and early warning of urban underground spaces.

[0025] Example 1

[0026] This embodiment describes an experimental device for simulating underground cavities, including an underground cavity simulation body 7 and a structural steel cover 6 that cooperates with the underground cavity simulation body. The structural steel cover is connected to a traction device, and the structural steel cover moves up and down along the underground cavity simulation body through the traction device to adjust the size of the simulated cavity. The traction device includes a traction drive host 10 and a counterweight device. The counterweight device is connected to the structural steel cover through a traction steel wire rope 2. Hooks are arranged around the structural steel cover and at its center to effectively drive the structural steel cover. Distributed fiber optic sensors 3 are laid parallel above the underground cavity simulation body to collect signals from simulated cavities of different sizes.

[0027] Specifically, the traction device also includes two traction guide pulleys 1, which are respectively located on both sides of the traction drive host 10. The traction steel wire rope is driven to move by the traction drive host and is wound around the two traction guide pulleys. One of the traction guide pulleys 1 is located on the center line of the structural steel cover, which ensures that the structural steel cover remains stable during the driving process of the traction steel wire rope. The top of the structural steel cover is provided with 6-10 branch traction steel wire ropes 5 evenly distributed along the top of the structural steel cover, so that the structural steel cover maintains force balance during the up and down movement. The branch traction steel wire ropes are gathered at one end and connected to the traction steel wire rope.

[0028] Furthermore, the counterweight device includes a counterweight guide rail 8 and a counterweight 9 that cooperates with the counterweight guide rail. The main body of the underground cavity simulation is a hollow cuboid wooden structure, with the inner wall coated with an insect-proof and moisture-proof coating 11 to ensure structural stability during use and to ensure the accuracy and precision of subsequent test data.

[0029] Distributed fiber optic sensors are vertically installed above the underground cavity simulation body at a depth of 0.3-1m, with a horizontal distance of 0.3-1m between the distributed fiber optic sensors and the underground cavity simulation body. During the specific testing process, a filling layer 4 is installed above the structural steel cover. The filling layer is a soil layer or a sand and gravel layer, and the filling layer is flush with the surrounding ground.

[0030] Example 2

[0031] This embodiment describes a test device for simulating underground cavities, including an underground cavity simulation body and a structural steel cover that cooperates with the underground cavity simulation body. The structural steel cover is connected to a traction device, and the structural steel cover moves up and down along the underground cavity simulation body through the traction device to adjust the size of the simulated cavity. The traction device includes a traction drive host and a counterweight device. The counterweight device is connected to the structural steel cover through a traction steel wire rope. Hooks are arranged around the perimeter and center of the structural steel cover to effectively drive the structural steel cover. Distributed fiber optic sensors are laid parallel above the underground cavity simulation body to collect signals from simulated cavities of different sizes.

[0032] Specifically, the simulated underground cavity is a 0.4m x 0.4m wooden cuboid without a lid. The wooden planks are 5-8mm thick and coated with a moisture-proof and insect-proof agent. A structural steel cover is 3m above the ground, forming a 0.4m x 0.4m x 7m cavity with the wooden base. Eight branched traction steel cables, evenly distributed around the perimeter and center of the structural steel cover, ensure its balance in all directions. Distributed fiber optic sensors are vertically installed above the simulated cavity at a depth of 0.5m, with a horizontal distance of 0.3m between the sensors and the simulated underground cavity.

[0033] When conducting simulated cavity size tests using distributed fiber optic sensors, soil should be placed above the structural steel cover to simulate a real field testing environment. The results of geological imaging using distributed fiber optic sensors are as follows... Figure 3 As shown, a noticeable cavity is observed within a horizontal range of 0.1m–0.5m and a vertical range of -3m–10m, which is consistent with the experimental results, proving that the distributed fiber optic sensing system is accurate and reliable in geological imaging.

[0034] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications or substitutions should be considered within the protection scope of the present invention.

Claims

1. A test apparatus for simulating a subterranean cavity, characterized by: The experimental setup includes a simulated underground cavity and a structural steel cover that works in conjunction with it. The structural steel cover is connected to a traction device, which moves up and down along the simulated underground cavity via the traction device to adjust the size of the simulated cavity. The traction device includes a traction drive unit and a counterweight, which is connected to the structural steel cover via a traction steel cable. Hooks are provided around the perimeter and at the center of the structural steel cover. Distributed fiber optic sensors are laid parallel above the simulated underground cavity.

2. A test apparatus for simulating a subterranean void according to claim 1, wherein: The traction device also includes two traction guide pulleys, which are located on both sides of the traction drive host. The traction wire rope is driven to move by the traction drive host and is wound around the two traction guide pulleys.

3. The test apparatus for simulating a subsurface void of claim 1, wherein: The counterweight device includes a counterweight guide rail and a counterweight that cooperates with the counterweight guide rail.

4. The test apparatus for simulating a subsurface void of claim 1, wherein: The underground cavity simulation is a hollow rectangular wooden structure with an insect-proof and moisture-proof coating on the inner wall.

5. The test apparatus for simulating a subsurface void of claim 1, wherein: The top of the structural steel cover is equipped with 6-10 branch traction steel wire ropes evenly distributed along the top of the structural steel cover, so that the structural steel cover maintains force balance during the up and down movement. The branch traction steel wire ropes are combined and connected to the traction steel wire rope.

6. The test apparatus for simulating a subsurface void of claim 1, wherein: The distributed fiber optic sensors are laid vertically above the underground cavity simulation body at a depth of 0.3-1m, and the horizontal distance between the distributed fiber optic sensors and the underground cavity simulation body is 0.3-1m.

7. The test apparatus for simulating a subsurface void of claim 1, wherein: The structural steel cover is equipped with a filling layer, which is a soil layer or a sand and gravel layer, and the filling layer is flush with the surrounding ground.

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