A device for collecting volatile organic compounds within cracks in a contaminated site intercept-bearing structure

Abstract

The application provides a device for collecting volatile organic compounds in cracks of a contaminated site sewage interception bearing structure, which comprises a gas storage assembly and a support frame, the gas storage assembly comprises a tank body which is a cylinder with a closed top end and an open bottom end; an opening and closing assembly is arranged at the open bottom end of the tank body, and the opening and closing assembly is used for opening and closing the open bottom end of the tank body; the tank body is hoisted on the support frame, and a gravimeter is arranged between the tank body and the support frame and used for measuring the weight of the tank body. The device for collecting volatile organic compounds in cracks of a contaminated site sewage interception bearing structure can collect volatile organic compounds in cracks of a damaged sewage interception bearing structure in situ for detection, and the detection accuracy is improved.

Description

Technical Field

[0001] This invention belongs to the field of performance testing technology for structures in contaminated sites. Specifically, it relates to a device for collecting volatile organic compounds in cracks of intercepting and bearing structures in contaminated sites. Background Technology

[0002] Horizontal interceptor structures in production workshops, tank areas, and roads of operating enterprises often serve a dual purpose: bearing external loads and preventing pollutant migration. These structures are mostly made of concrete, which is prone to cracking under external loads and corrosive effects from production wastewater, creating numerous fissures that become prime pathways for pollutant migration. In sites with volatile organic compound (VOC) pollution, VOCs migrate through these fissures into the production workshop or atmosphere, posing a threat to the health of production personnel. Simultaneous production and control measures require monitoring of horizontal structures in production workshops, tank areas, and roads to assess their service performance. The concentration of VOCs in cracks of damaged horizontal interceptor structures is a crucial basis for determining the extent of structural damage and formulating subsequent repair and remediation measures. However, current assessments of interceptor structures primarily rely on visual inspection and sampling testing. Visual inspection mainly involves visually monitoring the structural integrity and crack development, but it suffers from high subjectivity and difficulty in quantifying monitoring data. Core sampling testing is mainly used for areas with minor cracks. By collecting core samples from the structure, indoor tests are conducted to obtain the structure's permeability or diffusion coefficient. Since areas with severe damage are key areas of concern for pollutant migration, and the cracks in these areas are interconnected, making it impossible to obtain complete core samples, core sampling testing cannot be applied. Furthermore, the concentration of organic matter within the cracks of a damaged structure is a crucial parameter characterizing the ability of pollutants in the overlying soil of a horizontal structure to migrate to the outside environment, accurately reflecting the migration of pollutants through in-situ cracks. Currently, there is no suitable detection device capable of collecting organic matter concentration data from cracks in damaged horizontal structures such as production workshops, tank farms, and road surfaces in operating enterprises. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device for collecting volatile organic compounds in cracks of the intercepting and supporting structure of a contaminated site, which can collect volatile organic compounds in the cracks of the damaged intercepting and supporting structure for detection, thereby improving the accuracy of detection.

[0004] To solve the above-mentioned technical problems, the embodiments of the present invention adopt the following technical solutions:

[0005] This invention provides a device for collecting volatile organic compounds (VOCs) within cracks in a contaminated site interception and support structure. The VOCs include a gas storage component and a support frame. The gas storage component includes a tank, which is a cylinder with a closed top and an open bottom. An opening and closing component is provided at the bottom opening of the tank for opening and closing the bottom opening of the tank. The tank is suspended on the support frame, and a gravimeter is installed between the tank and the support frame to measure the weight of the tank.

[0006] As a further improvement of this embodiment of the invention, the opening and closing assembly includes a fixed plate and a rotating plate. The fixed plate is installed at the bottom opening of the tank. The fixed plate includes a fixed circular plate with a plurality of fan-shaped fixed connecting holes evenly spaced on it. Between two adjacent fixed connecting holes is a fan-shaped fixed blocking plate. The fixed connecting holes and the fixed blocking plates are equal in size and number. The rotating plate is located above the fixed plate and abuts against it. The rotating plate has the same structure as the fixed plate, with rotating connecting holes and rotating blocking plates. The rotating plate is connected to a servo motor installed at the top of the tank via a rotating shaft. The servo motor drives the rotating shaft to rotate the rotating plate, thereby opening and closing the bottom opening of the tank.

[0007] As a further improvement of this invention, the bottom edge of the rotating barrier is provided with a first limiting seal, and the top edge of the fixed barrier is provided with a second limiting seal.

[0008] As a further improvement of the present invention, a sealing cover is also included, wherein a second air inlet pipe is provided at the top of the sealing cover and a second air outlet pipe is provided at the bottom.

[0009] As a further improvement of this embodiment of the invention, a gas dispersion plate is provided in the upper part of the sealing cover.

[0010] As a further improvement of the present invention, the gas dispersion plate includes a plate body with a cavity, and an air inlet communicating with a second air inlet pipe is provided on the top surface of the plate body; a plurality of air outlet holes are evenly distributed on the bottom surface of the plate body.

[0011] As a further improvement of this embodiment of the invention, a sealing assembly is provided outside the tank.

[0012] As a further improvement of the present invention, the sealing assembly includes a sealing drive, a pair of connecting arms and a pair of semi-circular sealing rings. The pair of sealing rings are respectively connected to the sealing drive through the pair of connecting arms. The sealing drive is used to control the rotation of the connecting arms to drive the sealing rings to open and close.

[0013] As a further improvement of this embodiment of the invention, the diameter of the tank is 25 to 50 times the maximum width of the crack in the intercepting and bearing structure.

[0014] As a further improvement of this invention, during operation, the tank is placed in the sampling hole located at the crack of the sewage interception and bearing structure of the contaminated site, and the bottom of the tank and the bottom of the sampling hole are at a preset distance.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0016] The present invention provides a device for collecting volatile organic compounds (VOCs) within cracks in the intercepting and supporting structure of contaminated sites. This device utilizes a gas storage component's tank to collect VOCs from sampling holes located in the gaps of a horizontal barrier. The VOCs in the cracks migrate to the tank via diffusion. The tank is suspended on a support frame, and a gravimeter is used to measure its weight to determine if the VOCs are evenly diffused within the tank. Once the VOCs are evenly diffused, the concentration of VOCs in the tank is equal to the concentration within the crack. The measured VOC concentration in the tank is then the same as the concentration within the crack. This invention allows for in-situ collection of VOCs within the cracks of the intercepting and supporting structure, achieving the same concentration in the tank as within the crack, thus improving detection accuracy and effectively overcoming testing errors caused by sample disturbance in existing coring testing processes. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the volatile organic compound collection device inside the cracks of the contaminated site interception and bearing structure according to an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 Schematic diagram of the gas storage component;

[0019] Figure 3 (a) is Figure 2 The diagram shows a cross-section A-A' of the gas storage assembly with the bottom opening closed.

[0020] Figure 3 (b) is Figure 2 The diagram shows a cross-section B-B' of the gas storage assembly with the bottom opening closed.

[0021] Figure 3 (c) is Figure 2 The diagram shows a cross-section A-A' with the bottom opening of the gas storage component in the open state.

[0022] Figure 3 (d) is Figure 2 The diagram shows a cross-section B-B' of the gas storage component with the bottom opening in the open position.

[0023] Figure 3 (e) is Figure 2The diagram shows a C-C' cross-section of the gas storage assembly with the bottom opening closed.

[0024] Figure 4 (a) is Figure 2 A schematic diagram of the structure of the fixing barrier plate in the middle fixing plate;

[0025] Figure 4 (b) is Figure 2 A schematic diagram of the rotating baffle plate in the rotating plate;

[0026] Figure 4 (c) is Figure 3 (e) Schematic diagram of the D-D' section;

[0027] Figure 5 (a) is Figure 1 A schematic diagram of the sealing assembly in a closed state;

[0028] Figure 5 (b) is Figure 1 A schematic diagram of the middle sealing assembly in the open state;

[0029] Figure 6 (a) is Figure 1 Top view of the gas dispersion plate;

[0030] Figure 6 (b) is Figure 1 A bottom view of the gas dispersion plate.

[0031] In the diagram: Gas storage assembly 1, tank 11, rotating shaft 12, rotating plate 13, rotating connecting hole 131, rotating barrier plate 132, first limiting seal 133, fixing plate 14, fixing connecting hole 141, fixing barrier plate 142, second limiting seal 143, sealing piston 15, first air inlet pipe 16, first air outlet pipe 17, helium gas measuring probe 18, servo motor 19, fixing buckle 110, support frame 20, gravimeter 21, integrated port 22, power supply 23, sealing assembly 3, sealing drive component 31, connecting arm 32, sealing ring 33, information exchanger 4, sealing cover 5, second air inlet pipe 51, second air outlet pipe 52, gas dispersion plate 6, plate body 61, air outlet 62, sewage interception and bearing structure 7, sampling hole 8. Detailed Implementation

[0032] The technical solution of the present invention will be described in detail below.

[0033] This invention provides a device for collecting volatile organic compounds (VOCs) within cracks in the intercepting and supporting structure of a contaminated site, such as... Figure 1As shown, the system includes a gas storage assembly 1 and a support frame 20. The gas storage assembly 1 includes a tank 11, which is a cylinder closed at the top and open at the bottom. An opening and closing assembly is provided at the bottom opening of the tank 11 for opening and closing the bottom opening of the tank. Figure 2 As shown, the top of the tank 11 is provided with a first air inlet pipe 16 communicating with the inner cavity of the tank 11, and the tank 11 is provided with a first air outlet pipe 17. One end of the first air outlet pipe 17 is located at the bottom of the inner cavity of the tank 11, and the other end is located outside the tank 11. The tank 11 is hoisted on the support frame 20, and a gravity meter 21 is installed between the tank 11 and the support frame 20. The gravity meter is used to measure the weight of the tank 11.

[0034] In the above embodiment, the sampling device operates by creating a sampling hole 8 through the gap in the intercepting and supporting structure 7. The bottom opening of the tank is opened using an opening and closing assembly, and inert gas (preferably helium) is introduced through the first inlet pipe 16, allowing air inside the tank 11 to be discharged through the first outlet pipe 17. The volume of inert gas introduced can be determined based on the gas flow meter reading on the inert gas storage tank and the gas introduction time. Generally, the volume of inert gas introduced is 2 to 3 times the volume of the tank 11, and the air inside the tank 11 is considered emptied, at which point the introduction of inert gas is stopped. This fills the tank 11 with inert gas, sealing the openings of the first inlet pipe 16 and the first outlet pipe 17. The support frame 20 is fixed beside the sampling hole 8, and the gravimeter 21 and the tank 11 are hoisted. The tank 11 filled with inert gas is placed into the sampling hole 8, with a predetermined distance between the bottom of the tank and the bottom of the sampling hole. The bottom opening of the tank is opened by the opening and closing assembly, allowing volatile organic compounds (VOCs) in the contaminated foundation beneath the intercepting and supporting structure 7 to diffuse into the tank. The mass of the tank is measured periodically. When the difference between the current and previous measurements is less than 0.5% of the current measurement, it is considered that the VOCs are evenly diffused within the tank, and the bottom opening is closed by the opening and closing assembly. The tank 1 is then removed from the sampling port 8, and the concentration of VOCs within the tank is measured, thus obtaining the concentration of VOCs within the gap.

[0035] This embodiment of the device utilizes the tank of a gas storage component to collect volatile organic compounds (VOCs) from sampling holes opened in the gaps of a horizontal barrier. An inert gas is used as the background gas to overcome interference from VOCs in the ambient air. During the detection process, VOCs in the crack migrate to the tank of the gas storage component through diffusion. Simultaneously, the inert gas in the tank 11 migrates downwards into the pores of the contaminated soil, ultimately achieving a balance between the VOC concentration in the tank 11 and the VOC concentration in the underlying contaminated soil. The tank is hung on a support frame, and a gravimeter is used to measure the weight of the tank to determine whether the VOCs are evenly diffused within the tank. Once the VOCs are evenly diffused, the concentration of VOCs in the tank is the same as the concentration in the crack. The measured concentration of VOCs in the tank is then the concentration of VOCs in the crack. The device of this invention can collect volatile organic compounds in situ through the gaps in the intercepting and supporting structure, and achieve the same concentration of volatile organic compounds in the tank as the concentration of organic compounds in the crack, thereby improving the detection accuracy and providing support for the performance testing of similar horizontal barrier barriers in production enterprises.

[0036] As a preferred example, such as Figure 3 As shown, the opening and closing assembly includes a fixed plate 14 and a rotating plate 13. The fixed plate is installed at the bottom opening of the tank body 11, and the rotating plate 13 is located above the fixed plate 14 and abuts against the fixed plate 14. Figure 3 (b) and Figure 3 As shown in (d), the fixing plate 14 includes a fixing disc, on which a plurality of fan-shaped fixing communication holes 141 are evenly spaced. Between two adjacent fixing communication holes 141 are fan-shaped fixing barrier plates 142. The fixing communication holes 141 and the fixing barrier plates 142 are equal in size and number. The rotating plate 13 has the same structure as the fixing plate 14, as shown in (d). Figure 3 (a) and Figure 3 As shown in (c), the rotating plate 13 includes a rotating disc with a plurality of fan-shaped rotating connecting holes 131 evenly spaced on it. Between two adjacent rotating connecting holes 131 is a fan-shaped rotating blocking plate 132. The rotating connecting holes 131 and the rotating blocking plates 132 are equal in size and number. A servo motor 19 is fixedly mounted on the top of the tank 11 via a fixing buckle 110. The servo motor 19 is connected to one end of a rotating shaft 12, and the other end of the rotating shaft 12 extends into the tank 11 and connects to the rotating plate 13. The rotating shaft 12 is sealed to the perforation on the top surface of the tank 11 by a sealing piston 15. The servo motor drives the rotating shaft to rotate the rotating plate, thereby opening and closing the bottom opening of the tank.

[0037] This embodiment employs a rotating plate and a fixed plate with identical structures arranged vertically. Rotating the rotating plate changes the position of the rotating partition relative to the fixed connecting hole. When the rotating partition is opposite the fixed connecting hole, the fixed connecting hole is covered, and the opening between the bottom of the tank and the outside is closed. When the rotating connecting hole is opposite the fixed connecting hole, the fixed connecting hole, acting as the opening between the bottom of the tank and the outside, is opened. Furthermore, multiple fixed connecting holes can be closed or opened simultaneously, and are evenly distributed at the bottom of the tank. The horizontal rotation of the rotating plate achieves opening closure, which is easier to control than a pull-type opening and closing structure. It also has a larger total opening area, resulting in a larger and more uniform air intake per unit time, which is beneficial for the rapid and smooth entry of volatile organic compounds into the tank.

[0038] Preferably, as shown in the figure, the bottom edge of the rotating barrier 132 is provided with a first limiting seal 133, and the top edge of the fixed barrier 142 is provided with a second limiting seal 143. When the bottom opening of the tank is closed, the rotating plate is rotated so that the first limiting seal of the rotating barrier abuts against the second limiting seal of the fixed barrier. The first and second limiting seals not only serve to limit the rotation, ensuring that the rotating barrier completely covers the fixed connecting hole, and the rotating connecting hole is completely covered by the fixed barrier; but also seal the gap between the rotating barrier and the fixed barrier, preventing the leakage of volatile organic compounds in the tank after the collection is completed, which would affect the detection accuracy.

[0039] As a preferred example, the data acquisition device in this embodiment further includes a sealing cover 5, such as... Figure 1 As shown, the top of the sealing cover 5 is provided with a second air inlet pipe 51, and the bottom is provided with a second air outlet pipe 52. There are no gaps at the joint between the sealing cover 5 and the sewage interception and bearing structure 7. The diameter of the sealing cover 5 is more than 10 times the diameter of the sampling hole 8, and the height of the sealing cover 5 is more than 5 times the height of the sampling hole 8.

[0040] Before collecting volatile organic compounds, inert gas is introduced into the sealed enclosure 5. The volume of inert gas introduced can be determined based on the gas flow meter reading on the inert gas storage tank and the gas introduction time. Generally, the volume of inert gas introduced is 2 to 3 times the volume of the sealed enclosure 5. Once the air inside the sealed enclosure 5 is considered emptied, the introduction of inert gas is stopped, leaving the sealed enclosure 5 filled with inert gas. The ports of the second inlet pipe 52 and the second outlet pipe 53 are then closed.

[0041] In this embodiment, by covering the sampling hole with a sealing cover 5 and introducing inert gas, the tank 11 is isolated from the surrounding atmospheric environment, thereby eliminating the influence of volatile organic compounds in the atmospheric environment on the detection results.

[0042] Preferably, a gas dispersion plate 6 is provided in the upper part of the inner part of the sealing cover 5. Specifically, such as... Figure 6As shown, the gas dispersion plate 6 includes a plate body 61 with a cavity. The top surface of the plate body 61 has an air inlet that communicates with the second air inlet pipe 51. Multiple air outlets 62 are evenly distributed on the lower end surface of the plate body 61, and the sum of the areas of all air outlets 62 is greater than or equal to 60% of the area of ​​the lower end surface of the plate body 61. In this embodiment, the dispersion plate 6 is installed inside the sealing cover 5 to facilitate the rapid and uniform distribution of inert gas within the sealing cover 5, enabling rapid collection and shortening the detection time.

[0043] As a preferred example, such as Figure 1 As shown, a sealing assembly 3 is provided on the outside of the tank 11 and is located at the top of the sampling hole. Specifically, the sealing assembly 3 includes a sealing drive 31, a pair of connecting arms 32, and a pair of semi-circular sealing rings 33. The pair of sealing rings 33 are connected to the sealing drive 31 through the connecting arms, and the sealing drive 31 is used to control the rotation of the connecting arms to open and close the sealing rings. The sealing drive 31 is fixed next to the sampling hole, specifically on the base of the support frame. The pair of sealing rings surround the outside of the tank 11 and are located at the top of the sampling hole. The gravimeter measures the weight of the tank at fixed intervals. During the gravimeter measurement, the sealing drive 31 controls the rotation of the connecting arms to separate the pair of sealing rings; after the gravimeter finishes measuring, the sealing drive 31 controls the rotation of the connecting arms to close the pair of sealing rings, thereby sealing the gap between the side wall of the tank and the top of the sampling hole. In this embodiment, by providing an openable and closable sealing assembly 3 on the outside of the tank 11, the sealing rings are opened before measurement, so that the tank 11 is in a suspended state for weight testing, avoiding interference from the sealing rings on the weight test. After the measurement is completed, the sealing ring is closed to prevent volatile organic compounds in the polluted foundation under the intercepting structure from leaking through the gap between the tank 11 and the sampling hole 8.

[0044] Considering that volatile organic compounds (VOCs) in the cracks can migrate to the tank 11 through diffusion, achieving the same VOC concentration in the tank 11 as the concentration of organic compounds in the cracks is crucial for characterizing the concentration of organic compounds in the cracks. Preferably, the diameter of the tank 11 is 25 to 50 times the maximum width of the crack in the intercepting structure. If the diameter of the tank 11 is too large, it will take a long time to achieve equilibrium between the VOC concentration in the tank 11 and the concentration of organic compounds in the cracks, resulting in low detection efficiency. Moreover, a large diameter of the tank 11 requires opening a large sampling hole on the horizontal barrier, causing significant damage to the horizontal barrier. If the diameter of the tank 11 is too small, the amount of VOCs collected in the tank 11 will be small, leading to a large error in the detection results. Therefore, this embodiment uses a tank 11 with a diameter of 25 to 50 times the maximum width of the crack in the intercepting structure, which can improve both detection accuracy and detection efficiency.

[0045] Preferably, the sampling hole 8 is cylindrical, with the center of its top surface located on the gap in the intercepting and supporting structure. This design ensures that volatile pollutants in the contaminated foundation beneath the intercepting and supporting structure can smoothly diffuse and migrate to the tank 11, shortening the equilibrium time between the concentration of volatile organic compounds in the tank 11 and the concentration of organic compounds in the crack, thus improving detection efficiency. The diameter of the sampling hole 8 is larger than the diameter of the tank 11, with the difference not exceeding 0.5 cm. This ensures a gap between the tank 11 and the sampling hole, facilitating the insertion and removal of the tank from the sampling hole. It also prevents measurement errors caused by friction when measuring the weight of the tank, which could lead to incorrect judgments about the uniform diffusion of volatile organic compounds, thus affecting detection accuracy. Simultaneously, the small gap between the tank 11 and the sampling hole facilitates sealing, preventing volatile organic compounds in the contaminated foundation from migrating upwards through the gap between the tank 11 and the sampling hole.

[0046] The working process of the volatile organic compound collection device in the cracks of the pollution interception and bearing structure of the above-mentioned preferred embodiment is as follows:

[0047] Sampling hole 8 is opened at the crack in the sewage interception and bearing structure, and the gap on the side wall of sampling hole 8 is sealed.

[0048] The servo motor 19 is controlled to operate, driving the rotating plate 13 to rotate via the rotating shaft 12. This causes the rotating baffle 132 to align with the fixed connecting hole 141, thus sealing the canister. Helium gas is introduced through the first inlet pipe 16 and enters the canister. Air inside the canister enters the first outlet pipe 17 through the bottom opening and then exits. Once the air inside the canister 11 is emptied, the helium supply is stopped, filling the canister 11 with helium and sealing the openings of the first inlet pipe 16 and the first outlet pipe 17.

[0049] Fix the support frame 20 next to the sampling hole 8, hoist the gravimeter 21 and the tank 11, and place the helium-filled tank 11 into the sampling hole 8. Adjust the position of the tank so that the center of the tank's cross-section coincides with the center of the sampling hole's cross-section, the outer wall of the tank does not contact the inner wall of the sampling hole, and the bottom of the tank is at a preset distance from the bottom of the sampling hole. The sealing drive controls a pair of connecting arms to rotate and drive a pair of sealing rings to close, thereby sealing the gap between the side wall of the tank and the top of the sampling hole. Install the information exchanger 4 on the sealing cover 5 and place the sealing cover 5 above the sampling hole 8, with the center of the sampling hole 8's cross-section coinciding with the center of the sealing cover 5's cross-section. Seal the joint between the sealing cover 5 and the intercepting and bearing structure 7 with cement mortar. Introduce helium through the second inlet pipe 51, and the helium enters the sealing cover 5. The air inside the sealing cover 5 is discharged through the second outlet pipe 52. After the air inside the sealing cover 5 is emptied, stop introducing helium and seal the openings of the second inlet pipe 51 and the second outlet pipe 52.

[0050] The servo motor 19 is controlled to operate, driving the rotating plate 13 to rotate via the rotating shaft 12. This causes the rotating connecting hole 131 and the fixed connecting hole 141 to coincide, allowing volatile pollutants in the contaminated foundation to freely diffuse into the tank. Every two hours, the sealing drive controls a pair of connecting arms to rotate, causing a pair of sealing rings to separate. A gravimeter measures the weight of the tank, and after obtaining the weight, the sealing drive controls the pair of connecting arms to rotate, causing a pair of sealing rings to close. When the difference between the current measurement and the previous measurement is less than 0.5%, it is considered that the volatile pollutants have diffused evenly within the tank. The servo motor 19 is then controlled to operate, driving the rotating plate 13 to rotate via the rotating shaft. This causes the rotating barrier plate 132 to coincide with the fixed connecting hole 141, and the rotating connecting hole 131 and the fixed barrier plate 142 to coincide, thus sealing the tank.

[0051] Open the sealing cover 5 and remove the tank. Disassemble the other components and take them out of the site. Connect the first vent pipe 17 to a gas chromatograph-mass spectrometer to test the concentration of volatile organic compounds.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely for further illustrating the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A device for collecting volatile organic compounds (VOCs) within cracks in a contaminated site interception and support structure, characterized in that, The system includes a gas storage component (1) and a support frame (20). The gas storage component (1) includes a tank (11), which is a cylinder with a closed top and an open bottom. An opening and closing component is provided at the bottom opening of the tank (11) for opening and closing the bottom opening of the tank. The tank (11) is suspended on the support frame (20), and a gravity meter (21) is installed between the tank (11) and the support frame (20) for measuring the weight of the tank (11). During operation, the tank filled with inert gas is placed in the sampling hole located at the crack of the intercepting and bearing structure of the contaminated site, and the bottom of the tank is at a preset distance from the bottom of the sampling hole. A sealing component (3) is provided outside the tank (11) to seal the gap on the side wall of the sampling hole (8). The bottom opening of the tank is opened by the opening and closing component, so that the volatile organic compounds in the contaminated foundation under the intercepting and bearing structure diffuse into the tank. The weight of the can is measured using a gravimeter to determine whether the volatile organic compounds (VOCs) are evenly diffused within the can. Once the VOCs are evenly diffused, the bottom opening of the can is closed using an opening and closing mechanism. The can is then removed from the sampling hole, and the concentration of VOCs within the can is measured to obtain the concentration of VOCs in the gap.

2. The volatile organic compound collection device within the cracks of the contaminated site interception and bearing structure according to claim 1, characterized in that, The opening and closing assembly includes a fixed plate (14) and a rotating plate (13). The fixed plate is installed at the bottom opening of the tank (11). The fixed plate (14) includes a fixed disc. A plurality of fan-shaped fixed connecting holes (141) are evenly spaced on the fixed disc. Between two adjacent fixed connecting holes (141) is a fan-shaped fixed blocking plate (142). The fixed connecting holes (141) and the fixed blocking plates (142) are equal in size and number. The rotating plate (13) is located above the fixed plate (14) and abuts against the fixed plate (14). The rotating plate (13) has the same structure as the fixed plate (14) and has a rotating connecting hole (131) and a rotating blocking plate (132). The rotating plate (13) is connected to a servo motor installed at the top of the tank (11) through a rotating shaft (12). The servo motor is used to drive the rotating shaft to rotate the rotating plate, thereby opening and closing the bottom opening of the tank.

3. The volatile organic compound collection device within the cracks of the contaminated site interception and bearing structure according to claim 2, characterized in that, The bottom edge of the rotating barrier (132) is provided with a first limiting seal (133), and the top edge of the fixed barrier (142) is provided with a second limiting seal (143).

4. The volatile organic compound collection device within the cracks of the contaminated site interception and bearing structure according to claim 1, characterized in that, It also includes a sealing cover (5), with a second air inlet pipe (51) at the top and a second air outlet pipe (52) at the bottom.

5. The volatile organic compound collection device within the cracks of the contaminated site interception and bearing structure according to claim 4, characterized in that, The upper part of the sealing cover (5) is provided with a gas dispersion plate (6).

6. The volatile organic compound collection device within the cracks of the contaminated site interception and bearing structure according to claim 5, characterized in that, The gas dispersion plate (6) includes a plate body (61) with a cavity, and the top surface of the plate body (61) is provided with an air inlet that communicates with the second air inlet pipe (51); the bottom surface of the plate body (61) is evenly distributed with a plurality of air outlet holes (62).

7. The volatile organic compound collection device within the cracks of the contaminated site interception and bearing structure according to claim 6, characterized in that, The sealing assembly (3) includes a sealing drive (31), a pair of connecting arms (32) and a pair of semi-circular sealing rings (33). The pair of sealing rings (33) are connected to the sealing drive through the pair of connecting arms. The sealing drive is used to control the rotation of the connecting arms to drive the sealing rings to open and close.

8. The volatile organic compound collection device within cracks in the intercepting and bearing structure of a contaminated site according to claim 1, characterized in that, The diameter of the tank (11) is 25 to 50 times the maximum width of the crack in the intercepting and bearing structure.

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