Method suitable for rapidly detecting air tightness and gap of assembled subway grouting duct

Abstract

The invention relates to the technical field of metro station detection, in particular to a method suitable for rapidly detecting the air tightness and gaps of an assembled metro grouting duct. Comprising the following steps that S1, after the assembly type subway station is assembled, the assembly positions of components are checked, and the permeability of a grouting hole channel is detected; s2, pressurizing gas is injected into the grouting hole channel, pressure is stabilized, and airtightness detection is conducted; s3, when the air tightness in the grouting hole channel is poor, a gap existing in the grouting hole channel is detected, and the gap is blocked; s4, the blocked grouting hole channel is subjected to air tightness detection again, and if the air tightness is good, the follow-up grouting procedure of the grouting hole channel is carried out; and if the air tightness is poor, the step S3 and the step S4 are repeated until the air tightness in the grouting hole channel is good. The grouting quality of the assembly type subway station is guaranteed, and the structural strength of the splicing position of the assembly type subway station is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of subway station detection, in particular to a method for quickly detecting the airtightness and gaps of grouting ducts in prefabricated subways. Background Technique

[0002] Prefabricated subway stations are assembled from various prefabricated components. The joints between prefabricated structural components all adopt a grouting tenon and groove connection method. After the structure is assembled, joint grouting is required for all circumferential and longitudinal joints. The sealing rubber strip at the assembly contact surface of the components will move during the assembly extrusion, resulting in incomplete closure of the grouting space. In addition, pressure needs to be applied after the grouting liquid is filled to ensure the full grouting effect, which may lead to leakage of the grouting liquid and affect the grouting quality.

[0003] Generally, there are the following two situations for grouting leakage at subway joints: (1) Leakage is found at the splicing joint during the grouting process; (2) The grouting liquid overflows at the grouting outlet. After closing the inlet and outlet valves, the grouting liquid material has not solidified yet, but the micro-expansion of the grouting material during the solidification process causes displacement of the sealing rubber strip and leakage.

[0004] Currently, there is no relevant design and process for detecting the airtightness of grouting ducts in prefabricated subway stations. The grouting quality can only be reflected by visual observation, grouting time, and injection volume. In case of leakage, only subsequent plugging methods can be used, and the grouting quality of the grouting ducts of prefabricated components cannot be effectively controlled. The existing grouting method adopts a low-in and high-out exhaust method. The grouting duct space is narrow and long, and the grouting material such as epoxy resin liquid will solidify and harden in a short time, so the liquid in the duct will show intermittent solidification. When a leakage point is found, it is difficult to inject new epoxy resin liquid from the leakage point in the reverse direction for leak repair because the grouting duct is blocked by the solidified epoxy resin, resulting in the inability to discharge the gas in the duct and making it difficult to achieve the expected effect of full grouting and grouting quality. In addition, the components of prefabricated subway stations are large in volume, and it is difficult to locate the leakage point during inspection. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art, and propose a method for quickly detecting the airtightness and gaps of grouting ducts in prefabricated subways, which improves the detection rate of gaps, and completes the detection and plugging of gaps before grouting operation, provides good grouting conditions for improving grouting quality, ensures the grouting quality of prefabricated subway stations, and enhances the structural strength of the joints of prefabricated subway stations.

[0006] The technical solution of the present invention is: a method for quickly detecting the airtightness and gaps of grouting ducts in prefabricated subways, which includes the following steps:

[0007] S1. After the assembly of the prefabricated subway station is completed, inspect the component joints and detect the permeability of the grouting ducts.

[0008] S2. Inject pressurized gas into the grouting ducts and maintain a stable pressure for airtightness detection.

[0009] S3. When the airtightness of the grouting ducts is poor, detect the gaps existing in the grouting ducts and seal the gaps.

[0010] S4. Recover the dye gas in the ducts, and conduct airtightness detection on the grouting ducts again after sealing. If the airtightness is good, proceed with the subsequent grouting process for the grouting ducts; if the airtightness is poor, repeat steps S3 and S4 until the airtightness of the grouting ducts is good.

[0011] In the present invention, in step S1,

[0012] Conduct an appearance inspection on the component joints in the area where grouting construction is carried out, check for the movement and detachment of the rubber strips, and inspect whether the grouting ports and slurry discharge ports are blocked, and understand the trend and distribution of the grouting ducts.

[0013] Use a gas pump to fill the grouting ducts with gas through the grouting ports of the grouting ducts to remove foreign matters and impurities inside the grouting ducts. The foreign matters and impurities in the grouting ducts are discharged from the slurry discharge ports along with the gas. After the gas at the slurry discharge port is discharged smoothly, close the valve at the slurry discharge port.

[0014] In step S2, an air flow meter and a pressure gauge are installed at the slurry discharge port of the grouting ducts. Use a gas pump to inject pressurized gas into the grouting ducts through the grouting port. When the gas pressure in the grouting ducts reaches 0.2 MPa, stop injecting pressurized gas into the grouting ducts.

[0015] Stabilize the gas in the grouting ducts for 2 - 3 minutes. If the value of the pressure gauge remains unchanged, it indicates that the airtightness of the grouting ducts is good and the subsequent grouting process can be carried out; if the value of the pressure gauge shows a continuous downward trend, it indicates that there are gaps in the grouting ducts.

[0016] The specific implementation process of step S3 is described as follows:

[0017] S3.1. Prepare the dye gas: Load the fluorescent agent into the aerosol generator. Through the aerosol generator, convert the fluorescent agent into fine aerosol particles. The fluorescent agent in the form of aerosol particles is evenly mixed with nitrogen to form a uniformly distributed dye gas. Use an ultraviolet light source to irradiate the dye gas to make the dye gas emit fluorescence.

[0018] S3.2. The gas pump pressurizes the dyeing gas and injects the pressurized dyeing gas into the grouting channel through the gas pump. At the same time, the valve at the slurry outlet of the grouting channel is opened. When the dyeing gas is detected by ultraviolet light at the slurry outlet, the valve at the slurry outlet is closed.

[0019] Continue to inject the pressurized dyeing gas into the grouting channel. The air pressure value in the grouting channel gradually increases. When the air pressure value in the grouting channel reaches 0.24 MPa, use an ultraviolet lamp to irradiate along the outside of the grouting channel. When the ultraviolet lamp detects the fluorescent gas, it means that there is a gap at the position irradiated by the ultraviolet lamp. Locate and mark the gap point and repair the leak of the gap.

[0020] The fluorescent agent can be but is not limited to disperse fluorescent yellow 10GN or disperse fluorescent red G.

[0021] Use the gas pump to inject pressurized gas into the grouting channel through the grouting port of the grouting channel. When the air pressure in the grouting channel gradually increases to 0.24 MPa, suspend the injection of the pressurized gas and stabilize the gas in the grouting channel for 2 - 3 minutes.

[0022] When the reading of the barometer remains stable during the 0.24 MPa pressure stabilization stage of the grouting channel, it means that the grouting channel has good airtightness and no gaps when the pressure reaches 0.24 MPa, and the subsequent grouting work can be directly carried out.

[0023] If during the 0.24 MPa pressure stabilization stage of the grouting channel, the reading of the barometer shows a continuous downward trend, it indicates that there are still gaps in the grouting channel. Repeat steps S3 and S4 until the reading of the barometer remains stable.

[0024] The beneficial effects of the present invention are:

[0025] (1) Currently, the detection of gaps in subway grouting channels usually relies on the comparison between the theoretical amount and the actual amount of epoxy resin during the grouting process. Compared with the existing detection methods, using gas for detection can avoid a large amount of waste of epoxy resin.

[0026] (2) Compared with the existing detection methods for gaps in grouting channels, the equipment used in this application for airtightness detection and gap detection is simple, easy to operate, and has a fast detection speed. Based on the method described in this application, it is easy to implement, so it can detect multiple grouting channels simultaneously, greatly improving the detection efficiency of grouting channels.

[0027] (3) This application can accurately locate the gap position at the joint through the dyeing gas; after the gap detection is completed, the dyeing gas can be recycled at the slurry outlet of the grouting channel, and the amount of gas escaping from the gap is small, causing little pollution to the environment.

[0028] (4) Before the grouting process of the grouting duct, the airtightness and cracks of the grouting duct are detected. After detecting the cracks, the cracks are directly repaired. When the airtightness of the grouting channel meets the requirements, the grouting operation is carried out on the grouting duct. This can not only reduce the leakage of grouting materials, but also provide good grouting conditions for improving the grouting quality, ensuring the grouting quality of the prefabricated subway station and enhancing the structural strength of the splicing part of the prefabricated station. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic flow chart of the method of the present invention;

[0030] Figure 2 is a schematic distribution structure diagram of the grouting port and the slurry outlet in the grouting duct.

[0031] In the figure: 1 grouting port; 2 slurry outlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the accompanying drawings.

[0033] In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0034] As Figure 1 shown, the method for quickly detecting the airtightness and cracks of the grouting duct applicable to the prefabricated subway of the present application mainly includes the following steps.

[0035] The first step is that after the outer layer of the prefabricated subway station is assembled, the appearance of the component assembly gaps in the area where the grouting construction is located is inspected to check whether the rubber strips at the assembly gaps are displaced or fallen off, and whether the grouting inlet and outlet ducts are blocked, so as to understand the trend and distribution of the grouting ducts.

[0036] Since the prefabricated subway station is assembled and combined by prefabricated components, in order to ensure the tight connection between the concrete components and prevent water seepage and leakage at the joints, when designing and pouring the concrete components, grooves will be reserved at the joints. When splicing, the grooves are combined to form grouting ducts, and the splicing joints are sealed with rubber strips.

[0037] The cross-sectional view of the grouting duct is as Figure 2 shown, and the slurry outlet 2 is located above the grouting port 1.

[0038] Second step, quickly detect the permeability of the grouting duct. Use a gas pump to inject gas from the grouting port, and remove foreign objects and impurities inside the grouting duct through the gas. When it is determined that the gas at the slurry outlet can be smoothly discharged through the readings of the pressure gauge and the air flow meter, close the valve at the slurry outlet.

[0039] Third step, install air flow and air pressure detection equipment at the slurry outlet of the grouting duct. Inject pressurized gas into the grouting duct through a gas pump to conduct an airtightness test on the grouting duct. The gas pump injects pressurized gas at a certain flow rate at the grouting port. In this embodiment, the flow rate of the pressurized gas can be 100 - 200 L / min.

[0040] When the air pressure in the grouting duct reaches 0.2 MPa, suspend the injection of pressurized gas, and keep the gas temperature and pressure in the grouting duct for 2 - 3 minutes to simulate the pressurization effect during the static setting after the epoxy resin slurry is injected into the grouting duct during grouting.

[0041] According to the requirements in the seventh volume of the station project, "Station Structure and Waterproofing", the maximum pressure of the slurry inside the grouting duct during grouting shall not exceed 0.4 MPa, otherwise the properties of the sealing rubber strip will be damaged. Therefore, during the conventional grouting process, the pressure of the slurry in the grouting duct generally does not exceed 0.2 MPa. Therefore, in the airtightness detection process of this step of this application, the real grouting situation is simulated and pressurized to 0.2 MPa.

[0042] The air flow and air pressure detection equipment installed at the slurry outlet includes an air flow meter and a pressure gauge, which are used to detect the air flow value and air pressure value inside the grouting duct in real time.

[0043] If the air pressure value shown by the pressure gauge at the slurry outlet always remains at 0.2 MPa and does not change, it means that at the current air pressure, the airtightness of the grouting duct is good, and there is no gap at the assembled joint of the grouting duct, and the subsequent grouting process can be carried out.

[0044] If during the pressure stabilization stage, the value of the pressure gauge shows a continuous downward trend, it is necessary to detect the gap points of the grouting duct.

[0045] Fourth step, detect and locate the gaps in the grouting duct, and repair and seal the gaps.

[0046] As described above, during the confining pressure stage of the third step, if the value of the pressure gauge shows a continuous decrease, it means that there are gaps in the grouting duct. At this time, it is necessary to first detect and locate the gap points, find the specific location of the gaps, and perform the leak repair process on the gaps.

[0047] First, prepare the dyeing gas.

[0048] The staining gas used in this application is specifically a staining gas formed by staining nitrogen gas with a fluorescent dye. The fluorescent dye selected in this application needs to have the characteristics of good stability, non-toxicity, and good binding with nitrogen gas, such as disperse fluorescent yellow 10GN or disperse fluorescent red G.

[0049] The fluorescent dye needs to be evenly dispersed in nitrogen gas, so it is required that the fluorescent dye has good solubility or forms a stable colloidal suspension. In this application, the fluorescent dye is loaded into an aerosol generator, and through the aerosol generator, the fluorescent dye is converted into tiny aerosol particles. The aerosol particles formed by the fluorescent dye can be more easily mixed with nitrogen gas evenly, thus facilitating the uniform mixing of the fluorescent dye and nitrogen gas, and forming a uniformly distributed staining gas.

[0050] Use an ultraviolet light source to irradiate the nitrogen gas containing the fluorescent dye to excite the staining gas to emit fluorescence.

[0051] Next, use a gas pump to pressurize the staining gas, and inject the pressurized staining gas into the grouting channel through the grouting port through the gas pump. At the same time, open the valve at the slurry outlet of the grouting channel. When the staining gas is detected by ultraviolet light at the slurry outlet, close the valve at the slurry outlet. At the same time, continue to inject the staining gas into the grouting channel.

[0052] As the staining gas is continuously injected into the grouting channel, the air pressure value in the grouting channel gradually increases. When the air pressure value in the grouting channel reaches 0.24 MPa, use an ultraviolet lamp to irradiate along the outside of the grouting channel. When the ultraviolet lamp detects the fluorescent gas, it means that there is a gap at the position irradiated by the ultraviolet lamp. At this time, it is necessary to locate and mark this gap point, observe and record the size of the slurry leakage pores and perform the leak repair process.

[0053] During this process, it is necessary to continuously inject the staining gas into the grouting channel to ensure that the air pressure value in the grouting channel is stable at 0.24 MPa.

[0054] In the fifth step, after completing the detection and sealing of the gaps in the grouting channel, recover the staining gas in the channel and detect the airtightness of the grouting channel again.

[0055] After sealing the gaps detected in the fourth step, stop injecting the staining gas into the grouting channel, and connect the high-efficiency filter to the slurry outlet of the grouting channel. The staining gas in the grouting channel directly enters the high-efficiency filter to capture the aerosol particles in the staining gas and prevent the staining gas from polluting the air.

[0056] During the process of recovering the gas, the pressure in the grouting hole is detected by a barometer. When the pressure in the grouting hole drops to a certain pressure value and remains constant, the recovery of the dyeing gas is stopped.

[0057] Pressurized gas is injected into the grouting hole again through a gas pump to detect the airtightness of the grouting hole. The gas pump injects pressurized gas at a certain flow rate at the grouting port, and the flow rate of the pressurized gas can be 100 - 200 L / min. When the air pressure in the grouting hole reaches 0.24 MPa, the injection of the pressurized gas is paused, and the gas temperature and pressure in the grouting hole are maintained for 2 - 3 minutes to simulate the pressurization effect during the static setting of the epoxy resin slurry after it is injected into the grouting hole during grouting.

[0058] When the reading of the barometer can remain stable under the condition of a constant pressure of 0.24 MPa in the grouting hole, it indicates that the grouting hole has good airtightness and no gaps when the pressure in the channel reaches 0.24 MPa, and the grouting work can be directly carried out on this grouting hole.

[0059] If the reading of the barometer still shows a continuous downward trend under the condition of a constant pressure of 0.24 MPa in the grouting hole, it means that there are still gaps at the grouting hole. Repeat the gap detection and location and leak repair procedures in the fourth step, as well as the airtightness detection work in the fifth step, until the reading of the barometer at the slurry outlet remains stable under the condition of a constant pressure of 0.24 MPa in the grouting hole.

[0060] Since the main component of the grouting material for the grouting holes of the prefabricated station is epoxy resin, according to experimental research, epoxy resin has a micro - expansion characteristic during solidification, and its expansion coefficient is about 1.5 - 7 ppm / K. Therefore, in this step, it is necessary to pressurize to 0.24 MPa and maintain a constant pressure to simulate the micro - expansion process during the solidification process of epoxy resin in the grouting hole.

[0061] Sixth step, after the airtightness detection work of this grouting hole is completed, disassemble the air flow and pressure detection equipment at the slurry outlet, and conduct the airtightness detection of the next grouting hole.

[0062] The above has introduced in detail the method for quickly detecting the air tightness and gaps of the grouting channels for prefabricated subways provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for quickly detecting the airtightness and gaps of assembled subway grouting channels, characterized in that It includes the following steps: After the assembly of the prefabricated subway station is completed, check the assembly joints of the components and detect the permeability of the grouting ducts; Inject pressurized gas into the grouting ducts and maintain the pressure for airtightness detection; When the airtightness of the grouting ducts is poor, detect the gaps existing in the grouting ducts and seal the gaps; Recover the dye gas in the ducts, and conduct airtightness detection on the grouting ducts again after sealing. If the airtightness is good, proceed with the subsequent grouting process for the grouting ducts; if the airtightness is poor, repeat steps S3 and S4 until the airtightness of the grouting ducts is good.

2. The airtightness and gap rapid detection method for prefabricated subway grouting ducts according to claim 1, characterized in that In step S1, Conduct an appearance inspection on the assembly joints of the components in the area where grouting construction is located, check for movement and detachment of the rubber strips, and check whether the grouting ports and slurry outlets are blocked, and understand the trend and distribution of the grouting ducts; Use a gas pump to fill the grouting ducts with gas through the grouting ports of the grouting ducts to remove foreign matters and impurities inside the grouting ducts. The foreign matters and impurities in the grouting ducts are discharged from the slurry outlets along with the gas. After the gas at the slurry outlets is smoothly discharged, close the valves at the slurry outlets.

3. The airtightness and gap rapid detection method for prefabricated subway grouting ducts according to claim 1, characterized in that In step S2, an air flow meter and a pressure gauge are installed at the slurry outlet of the grouting ducts. Use a gas pump to inject pressurized gas into the grouting ducts through the grouting ports. When the gas pressure in the grouting ducts reaches 0.2 MPa, stop injecting pressurized gas into the grouting ducts; Maintain the pressure of the gas in the grouting ducts for 2 - 3 minutes. If the value of the pressure gauge remains unchanged, it indicates that the airtightness of the grouting ducts is good and the subsequent grouting process can be carried out; if the value of the pressure gauge shows a continuous downward trend, it indicates that there are gaps in the grouting ducts.

4. The airtightness and gap rapid detection method for the prefabricated subway grouting duct according to claim 1, characterized in that The specific implementation process of step S3 is as described below: S3.1: Prepare the dye gas: Load the fluorescent agent into an aerosol generator. Through the aerosol generator, convert the fluorescent agent into fine aerosol particles. The aerosol particle - shaped fluorescent agent is uniformly mixed with nitrogen to form a uniformly distributed dye gas. Use an ultraviolet light source to irradiate the dye gas to make the dye gas emit fluorescence; The gas pump pressurizes the dye gas and injects the pressurized dye gas into the grouting ducts through the gas pump. At the same time, open the valve at the slurry outlet of the grouting ducts. When the dye gas is detected by ultraviolet light at the slurry outlet, close the valve at the slurry outlet; Continue to inject pressurized dye gas into the grouting ducts. The air pressure value in the grouting ducts gradually increases. When the air pressure value in the grouting ducts reaches 0.24 MPa, use an ultraviolet lamp to irradiate along the outside of the grouting ducts. When the ultraviolet lamp detects the fluorescent gas, it indicates that there is a gap at the position irradiated by the ultraviolet lamp. Locate and mark the gap point and repair the leak of the gap.

5. The airtightness and gap rapid detection method for prefabricated subway grouting ducts according to claim 4, characterized in that, The fluorescent agent can be, but is not limited to, dispersed fluorescent yellow 10GN or dispersed fluorescent red G.

6. According to the method for rapid detection of airtightness and gaps of grouting ducts applicable to prefabricated subways according to claim 1, characterized in that, Use a gas pump to inject pressurized gas into the grouting duct through the grouting port of the grouting duct. When the air pressure in the grouting duct gradually increases to 0.24 MPa, suspend the injection of pressurized gas and stabilize the gas in the grouting duct for 2 - 3 minutes; When the air pressure gauge reading remains stable during the 0.24 MPa pressure stabilization stage of the grouting duct, it indicates that the grouting duct has good airtightness and no gaps when the pressure reaches 0.24 MPa, and subsequent grouting work can be directly carried out; If the air pressure gauge reading shows a continuous downward trend during the 0.24 MPa pressure stabilization stage of the grouting duct, it indicates that there are still gaps in the grouting duct. Repeat steps S3 and S4 until the air pressure gauge reading remains stable.

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