A neon-based indoor simulation test method for gas emission from tunnel shield slag

Abstract

The present invention discloses a neon-based indoor simulation test method for tunnel shield slag gas emission, comprising: 1. constructing a simulation test device; 2. preparing neon gas capsules; 3. preparing simulated soil samples; 4. simulating the emission of slag gas with neon gas; 5. analyzing test data to obtain the emission law of slag gas. The simulation test process of the present invention is reasonably designed, and the simulation test device is used to simulate the emission of gas in the tunnel shield slag discharge process by using neon gas, and the emission law of neon gas in the simulated soil sample discharge process can be obtained. The inversion model of soil bin gas content is constructed by random forest algorithm to obtain the emission law of slag gas, and the emission law of gas accompanying slag discharge can be reflected by simulation test data.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering, and in particular relates to a neon-based indoor simulation test method for tunnel shield slag gas emission. Background Art

[0002] Gas leakage is a common phenomenon in tunnel shield construction, which poses a major hidden danger to construction safety. Therefore, it is necessary to accurately grasp the behavior and law of gas leakage during shield construction. At the construction site, by setting up gas sensors, indicators such as gas concentration can be reflected to a certain extent, but there is a lot of randomness, and it is impossible to accurately obtain the law of gas leakage. The traditional indoor test method for gas leakage has great safety hazards, and it is impossible to accurately restore the slag structure and gas leakage path under actual working conditions, which brings certain obstacles to gas leakage testing. To this end, a safe and controllable indoor simulation test method for gas leakage in tunnel shield slag based on neon gas should be provided. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an indoor simulation test method for gas emission of tunnel shield slag based on neon gas in view of the deficiencies in the above-mentioned prior art. The simulation test process is reasonably designed, and a simulation test device is used to simulate the gas emission in the process of tunnel shield slag discharge by using neon gas. The emission law of neon gas in the simulated soil sample discharge process can be obtained, and an inversion model of the gas content in the soil bin is constructed by a random forest algorithm to obtain the emission law of slag gas, so that the emission law of gas in the process of slag discharge can be reflected through simulation test data.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a neon-based indoor simulation test method for tunnel shield slag gas emission, characterized in that: the test method comprises the following steps:

[0005] Step 1: Build a simulation test device:

[0006] The simulation test device comprises a simulated shield soil bin body placed on a base, a partition plate and a belt conveyor arranged in the simulated shield soil bin body, a clearance gap for the belt conveyor to pass through is opened at the bottom of the partition plate, the partition plate divides the inner cavity of the simulated shield soil bin body into a simulated soil bin and a simulated outer bin, the lower end platform of the belt conveyor is located in the simulated soil bin, the upper end platform of the belt conveyor is located in the simulated outer bin, and a first high-precision neon gas detector for real-time detection of neon gas concentration in the simulated soil bin is arranged in the simulated soil bin;

[0007] Step 2, preparing neon capsules;

[0008] The neon gas is sealed in an ellipsoidal gelatin capsule to form a neon gas capsule, wherein the neon gas capsule can be quickly dissolved after contacting water;

[0009] Step 3: preparing simulated soil samples;

[0010] Collect the original slag from the construction tunnel, dry it to form a slag soil sample, mix a plurality of neon gas capsules with the slag soil sample to form a simulated soil sample, put the simulated soil sample into a square box with an opening on the top, a bracket is installed across the top of the square box, and a second high-precision neon gas detector is installed on the bracket;

[0011] Step 4: Use neon gas to simulate the escape of soil methane. The specific process includes:

[0012] Step 401, referring to the moisture content of the original slag in the construction tunnel, weigh a certain amount of pure water and pour it into the square box containing the simulated soil sample, stir it thoroughly so that the multiple neon capsules in the simulated soil sample are fully in contact with the pure water, then transfer the square box containing the simulated soil sample to the lower platform of the belt conveyor, let it stand for 5 minutes, and use the first high-precision neon detector to detect the change of neon concentration in the simulated soil bin in real time;

[0013] Step 402: when the neon gas concentration growth rate detected by the first high-precision neon gas detector no longer changes, start the belt conveyor, and use the belt conveyor to transport the square box containing the simulated soil sample from the simulated soil bin to the simulated external bin; use the second high-precision neon gas detector to detect the neon gas concentration emitted by the simulated soil sample in real time, and record the neon gas concentration values ​​of the simulated soil sample at different positions on the belt conveyor;

[0014] Step 5: Analyze the test data to obtain the law of soil methane emission:

[0015] By analyzing the neon concentration value data of the simulated soil sample at different positions on the belt conveyor, the neon emission law in the simulated soil sample is obtained, and an inversion model of the soil silo gas content is constructed by the random forest algorithm to obtain the slag soil gas emission law.

[0016] The above-mentioned neon-based indoor simulation test method for tunnel shield slag gas emission is characterized in that: five neon gas detection points are set on the belt conveyor, and the five neon gas detection points are respectively 1# neon gas detection point, 2# neon gas detection point, 3# neon gas detection point, 4# neon gas detection point and 5# neon gas detection point, 1# neon gas detection point is located on the low-end platform, 5# neon gas detection point is located on the high-end platform, 2# neon gas detection point, 3# neon gas detection point and 4# neon gas detection point are arranged at equal intervals on the inclined surface of the belt conveyor.

[0017] The above-mentioned neon-based indoor simulation test method for tunnel shield slag gas emission is characterized in that: in step 2, the process of preparing the neon capsule is:

[0018] Dissolve gelatin in a water solvent to prepare a gelatin solution, wherein the temperature range of the water solvent is 60°C to 70°C; use a capsule filling machine to inject the dissolved gelatin solution into a capsule mold, cool and solidify it to prepare a capsule molding; after the capsule is formed, introduce neon gas from a neon bottle into the capsule, use a neon pump or a compressed gas device to ensure that the neon gas is filled to the required pressure, then seal the capsule, and finally use an airtightness testing device to check whether the capsule is intact and leak-free.

[0019] The above-mentioned neon-based indoor simulation test method for tunnel shield slag gas emission is characterized in that the neon content in each cubic meter of the simulated soil sample ranges from 0.002 cubic meters to 0.01 cubic meters.

[0020] The above-mentioned neon-based indoor simulation test method for tunnel shield slag gas emission is characterized in that: the low-end platform is installed on the first support frame, and the high-end platform is installed on the second support frame.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The present invention establishes a simulation test device in a laboratory, and uses the simulation test device to realize the use of neon gas to simulate the gas emission in the process of tunnel shield slag discharge. In the process of dissolving and releasing multiple neon gas capsules in the simulated soil sample, a first high-precision neon gas detector is used to detect the change of neon gas concentration in the simulated soil bin in real time. In the process of simulating the discharge of simulated soil samples by a belt conveyor, a second high-precision neon gas detector is used to detect the concentration of neon gas emitted from the simulated soil sample in real time, and the neon gas concentration values ​​of the simulated soil sample at different positions on the belt conveyor are recorded, so as to obtain the emission law of neon gas in the process of simulated soil sample discharge. Finally, an inversion model of soil bin gas content is constructed by random forest algorithm to obtain the emission law of slag gas, so as to realize that the emission law of gas accompanying slag discharge can be reflected by simulation test data.

[0023] 2. In the present invention, neon gas is sealed in an ellipsoidal gelatin capsule to form a neon gas capsule. Since the neon gas capsule can be quickly dissolved in water, a plurality of neon gas capsules are fully stirred with a slag soil sample to form a simulated soil sample. The simulated soil sample is placed in a square box with an opening at the top, and a certain amount of pure water is added to the simulated soil sample, which is fully stirred to make the plurality of neon gas capsules in the simulated soil sample fully contact with the pure water. The plurality of ellipsoidal gelatin capsules are dissolved in water, and the neon gas is released into the simulated soil sample, and gradually escapes from the simulated soil sample into the simulated shield soil bin. By dissolving the neon gas capsules, the content of neon gas in the simulated soil sample can be quantitatively controlled, and the simulation test process is simple and easy to operate.

[0024] 3. The simulation test process of the present invention is reasonably designed, simple and easy to operate, and convenient for promotion and application.

[0025] In summary, the simulation test process of the present invention is reasonably designed. The simulation test device is used to simulate the gas dispersion during the discharge of tunnel shield slag by using neon gas. The dispersion law of neon gas in the simulated soil sample discharge process can be obtained. The inversion model of the gas content in the soil bin is constructed by the random forest algorithm to obtain the dispersion law of slag gas. The simulation test data can be used to reflect the dispersion law of gas in the process of slag discharge.

[0026] The present invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the present invention.

[0028] Figure 2 This is a diagram showing the use status of the square box containing simulated soil samples of the present invention standing still on a low-end platform.

[0029] Figure 3 This is a diagram showing the use status of a square box containing simulated soil samples of the present invention moving on a belt conveyor.

[0030] Figure 4 It is a schematic diagram of the connection structure of the square box containing the slag soil sample and the neon capsule, the bracket and the second high-precision neon detector of the present invention.

[0031] Description of reference numerals:

[0032] 1—simulated shield soil bin; 2—partition plate; 3-1—simulated soil bin;

[0033] 3-2—simulated outer warehouse; 4—first high-precision neon gas detector; 5—belt conveyor;

[0034] 6—base; 7—square box; 7-1—bracket;

[0035] 8—soil sample; 9—neon gas capsule; 10—second highest precision neon gas detector;

[0036] 11-1—first support frame; 11-2—second support frame. DETAILED DESCRIPTION

[0037] like Figures 1 to 4 A neon-based indoor simulation test method for tunnel shield slag gas emission is shown, and the test method comprises the following steps:

[0038] Step 1: Build a simulation test device:

[0039] The simulation test device comprises a simulated shield soil bin body 1 placed on a base 6, a partition plate 2 and a belt conveyor 5 arranged in the simulated shield soil bin body 1, a clearance gap 2-1 for the belt conveyor 5 to pass through is opened at the bottom of the partition plate 2, the partition plate 2 divides the inner cavity of the simulated shield soil bin body 1 into a simulated soil bin 3-1 and a simulated outer bin 3-2, the lower end platform 5-1 of the belt conveyor 5 is located in the simulated soil bin 3-1, and the upper end platform 5-2 of the belt conveyor 5 is located in the simulated outer bin 3-2, and the simulated soil bin 3-1 is provided with a first high-precision neon gas detector 4 for real-time detection of neon gas concentration in the simulated soil bin 3-1;

[0040] Step 2: preparing neon capsule 9;

[0041] The neon gas is sealed in an ellipsoidal gelatin capsule to form a neon gas capsule 9, wherein the neon gas capsule 9 can be quickly dissolved when in contact with water;

[0042] Step 3: preparing simulated soil samples;

[0043] The original slag soil is collected from the construction tunnel, dried to form a slag soil sample 8, and multiple neon capsules 9 are fully mixed with the slag soil sample 8 to form a simulated soil sample, which is placed in a square box 7 with an open top. A bracket 7-1 is installed across the top of the square box 7, and a second high-precision neon gas detector 10 is installed on the bracket 7-1;

[0044] Step 4: Use neon gas to simulate the escape of soil methane. The specific process includes:

[0045] Step 401, referring to the moisture content of the original slag in the construction tunnel, weigh a certain amount of pure water and pour it into the square box 7 containing the simulated soil sample, stir it thoroughly, so that the multiple neon capsules 9 in the simulated soil sample are fully in contact with the pure water, then transfer the square box 7 containing the simulated soil sample to the lower platform 5-1 of the belt conveyor 5, let it stand for 5 minutes, and use the first high-precision neon detector 4 to detect the change of neon concentration in the simulated soil bin 3-1 in real time;

[0046] Step 402: when the neon gas concentration growth rate detected by the first high-precision neon gas detector 4 no longer changes, the belt conveyor 5 is turned on, and the square box 7 containing the simulated soil sample is transported from the simulated soil bin 3-1 to the simulated outer bin 3-2 by the belt conveyor 5; the neon gas concentration emitted by the simulated soil sample is detected in real time by the second high-precision neon gas detector 10, and the neon gas concentration values ​​of the simulated soil sample at different positions on the belt conveyor 5 are recorded;

[0047] Step 5: Analyze the test data to obtain the law of soil methane emission:

[0048] By analyzing the neon concentration value data of the simulated soil sample at different positions on the belt conveyor 5, the neon emission law in the simulated soil sample is obtained, and an inversion model of the soil silo gas content is constructed by the random forest algorithm to obtain the slag soil gas emission law.

[0049] In this embodiment, a simulation test device is established in the laboratory, and neon gas is used to simulate the gas emission in the process of tunnel shield slag discharge. In the process of dissolving and releasing multiple neon gas capsules 9 in the simulated soil sample, the first high-precision neon gas detector 4 is used to detect the change of neon gas concentration in the simulated soil bin 3-1 in real time. In the process of simulating the discharge of simulated soil samples by the belt conveyor 5, the second high-precision neon gas detector 10 is used to detect the concentration of neon gas emitted from the simulated soil sample in real time, and the neon gas concentration values ​​of the simulated soil sample at different positions on the belt conveyor 5 are recorded. The emission law of neon gas in the process of simulated soil sample discharge can be obtained. Finally, an inversion model of the soil bin gas content is constructed by the random forest algorithm to obtain the emission law of slag gas, which can reflect the emission law of gas accompanying slag discharge through simulation test data.

[0050] In this embodiment, neon gas is sealed in an ellipsoidal gelatin capsule to form a neon gas capsule 9. Since the neon gas capsule 9 can be quickly dissolved in water, a plurality of neon gas capsules 9 are fully stirred with a slag soil sample 8 to form a simulated soil sample. The simulated soil sample is placed in a square box 7 with an opening at the top, and then a certain amount of pure water is added to the simulated soil sample and fully stirred so that the plurality of neon gas capsules 9 in the simulated soil sample are fully in contact with the pure water. The plurality of ellipsoidal gelatin capsules are dissolved in water, releasing the neon gas into the simulated soil sample, and the neon gas gradually escapes from the simulated soil sample into the simulated shield soil bin body 1. By dissolving the neon gas capsules 9, the content of neon gas in the simulated soil sample can be quantitatively controlled, and the simulation test process is simple and easy to operate.

[0051] In this embodiment, in step three, the volume of the simulated soil sample ranges from 0.05 cubic meters to 0.2 cubic meters.

[0052] In this embodiment, the number of the first high-precision neon gas detectors 4 is four, and the four first high-precision neon gas detectors 4 are arranged at equal intervals on the inner surface of the right side plate of the simulated shield soil bin body 1. The four first high-precision neon gas detectors 4 are marked as detector No. 1, detector No. 2, detector No. 3 and detector No. 4 from bottom to top.

[0053] In this embodiment, five groups of tests were conducted by changing the neon content in each cubic meter of simulated soil sample, and the detection data of the four first high-precision neon detectors 4 during the five groups of tests were recorded in the following table:

[0054]

[0055]

[0056] In this embodiment, five neon gas detection points are set on the belt conveyor 5, and the five neon gas detection points are respectively 1# neon gas detection point, 2# neon gas detection point, 3# neon gas detection point, 4# neon gas detection point and 5# neon gas detection point. 1# neon gas detection point is located on the low-end platform 5-1, 5# neon gas detection point is located on the high-end platform 5-2, 2# neon gas detection point, 3# neon gas detection point and 4# neon gas detection point are arranged at equal intervals on the inclined surface of the belt conveyor 5.

[0057] In this embodiment, in step 402, the belt conveying speed of the belt conveyor 5 is 0.1 m / s.

[0058] In the actual test, the detection data of the second high-precision neon gas detector 10 at five neon gas detection points during five groups of tests are recorded in the following table:

[0059]

[0060]

[0061] In this embodiment, in step 2, the process of preparing the neon capsule 9 is as follows:

[0062] Dissolve gelatin in a water solvent to prepare a gelatin solution, wherein the temperature range of the water solvent is 60°C to 70°C; use a capsule filling machine to inject the dissolved gelatin solution into a capsule mold, cool and solidify it to prepare a capsule molding; after the capsule is formed, introduce neon gas from a neon bottle into the capsule, use a neon pump or a compressed gas device to ensure that the neon gas is filled to the required pressure, then seal the capsule, and finally use an airtightness testing device to check whether the capsule is intact and leak-free.

[0063] In this embodiment, the neon content in each cubic meter of the simulated soil sample ranges from 0.002 cubic meters to 0.01 cubic meters.

[0064] In this embodiment, the low-end platform 5 - 1 is installed on the first support frame 11 - 1, and the high-end platform 5 - 2 is installed on the second support frame 11 - 2.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A neon-based indoor simulation test method for tunnel shield slag gas emission, characterized in that: The test method comprises the following steps: Step 1: Build a simulation test device: The simulation test device comprises a simulated shield soil bin body (1) placed on a base (6), a partition plate (2) arranged in the simulated shield soil bin body (1) and a belt conveyor (5); a clearance gap (2-1) for the belt conveyor (5) to pass through is provided at the bottom of the partition plate (2); the partition plate (2) divides the inner cavity of the simulated shield soil bin body (1) into a simulated soil bin (3-1) and a simulated outer bin (3-2); the lower end platform (5-1) of the belt conveyor (5) is located in the simulated soil bin (3-1); the upper end platform (5-2) of the belt conveyor (5) is located in the simulated outer bin (3-2); and a first high-precision neon gas detector (4) for real-time detection of neon gas concentration in the simulated soil bin (3-1) is arranged in the simulated soil bin (3-1); Step 2: preparing neon capsules (9); The neon gas is sealed in an ellipsoidal gelatin capsule to form a neon gas capsule (9), wherein the neon gas capsule (9) can be quickly dissolved after contacting water; Step 3: preparing simulated soil samples; Original slag soil is collected from a construction tunnel, dried to form a slag soil sample (8), multiple neon gas capsules (9) are fully mixed with the slag soil sample (8) to form a simulated soil sample, and the simulated soil sample is placed in a square box (7) with an opening at the top, a bracket (7-1) is installed across the top of the square box (7), and a second high-precision neon gas detector (10) is installed on the bracket (7-1); Step 4: Use neon gas to simulate the escape of soil methane. The specific process includes: Step 401, referring to the moisture content of the original slag in the construction tunnel, weigh a certain amount of pure water and pour it into the square box (7) containing the simulated soil sample, and stir it thoroughly so that the multiple neon capsules (9) in the simulated soil sample are fully in contact with the pure water. Then, the square box (7) containing the simulated soil sample is transferred to the lower platform (5-1) of the belt conveyor (5), and left to stand for 5 minutes. The change of neon concentration in the simulated soil bin (3-1) is detected in real time by using the first high-precision neon detector (4); Step 402: When the neon gas concentration growth rate detected by the first high-precision neon gas detector (4) no longer changes, the belt conveyor (5) is turned on, and the square box (7) containing the simulated soil sample is transported from the simulated soil bin (3-1) to the simulated outer bin (3-2) by the belt conveyor (5); the concentration of neon gas emitted by the simulated soil sample is detected in real time by the second high-precision neon gas detector (10), and the neon gas concentration values ​​of the simulated soil sample at different positions on the belt conveyor (5) are recorded; Step 5: Analyze the test data to obtain the law of soil methane emission: By analyzing the neon concentration value data of the simulated soil sample at different positions on the belt conveyor (5), the neon emission law in the simulated soil sample is obtained, and an inversion model of the soil silo gas content is constructed by a random forest algorithm to obtain the soil slag gas emission law.

2. A neon-based indoor simulation test method for tunnel shield slag gas emission according to claim 1, characterized in that: Five neon gas detection points are set on the belt conveyor (5), and the five neon gas detection points are respectively neon gas detection point #1, neon gas detection point #2, neon gas detection point #3, neon gas detection point #4 and neon gas detection point #5. The neon gas detection point #1 is located on the low-end platform (5-1), the neon gas detection point #5 is located on the high-end platform (5-2), and the neon gas detection point #2, neon gas detection point #3 and neon gas detection point #4 are arranged at equal intervals on the inclined surface of the belt conveyor (5).

3. A neon-based indoor simulation test method for tunnel shield slag gas emission according to claim 1, characterized in that: In step 2, the process of preparing the neon capsule (9) is as follows: Dissolve gelatin in a water solvent to prepare a gelatin solution, wherein the temperature range of the water solvent is 60°C to 70°C; use a capsule filling machine to inject the dissolved gelatin solution into a capsule mold, cool and solidify it to prepare a capsule molding; after the capsule is formed, introduce neon gas from a neon bottle into the capsule, use a neon pump or a compressed gas device to ensure that the neon gas is filled to the required pressure, then seal the capsule, and finally use an airtightness testing device to check whether the capsule is intact and leak-free.

4. A neon-based indoor simulation test method for tunnel shield slag gas emission according to claim 1, characterized in that: The neon content in each cubic meter of the simulated soil sample ranges from 0.002 cubic meters to 0.01 cubic meters.

5. A neon-based indoor simulation test method for tunnel shield slag gas emission according to claim 1, characterized in that: The low-end platform (5-1) is installed on a first support frame (11-1), and the high-end platform (5-2) is installed on a second support frame (11-2).

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