A synchronous grouting and secondary grouting construction method for a shield

Abstract

The application discloses a kind of synchronous grouting and secondary grouting construction methods of shield, comprising the following steps: S1, erect grouting trolley: the grouting trolley is connected with shield machine frame;Synchronous grouting liquid storage stirring tank, secondary grouting device and cleaning device are provided on the grouting trolley;S2, preparation and transportation synchronous grouting liquid;S3, synchronous grouting: using the synchronous grouting pipeline and synchronous grouting pump built-in in shield tail, when grouting pressure reaches set value or grouting quantity reaches set value, synchronous grouting is stopped, and synchronous grouting pipeline and synchronous grouting pump are cleaned by cleaning device;S4, secondary grouting: carry out secondary grouting in the grouting hole reserved on corresponding segment by the secondary grouting device;When grouting pressure reaches set value, secondary grouting is stopped, and the secondary grouting device is cleaned by cleaning device.The application can effectively fill the gap between shield tail and building, reinforce the stratum around segment, improve grouting construction efficiency and effect.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology. More specifically, this invention relates to a method for simultaneous grouting and secondary grouting in TBM construction. Background Technology

[0002] Ground loss caused by shield tunneling and reconsolidation of the remolded soil around the shield tunnel due to disturbance or shear failure are important causes of surface settlement. To reduce and prevent surface settlement, during shield tunneling, grouting should be carried out as soon as possible in the annular gap behind the lining after the shield tail emerges. This synchronous grouting fills the gap between the shield tail and the excavation profile, and is usually performed simultaneously through the grouting pipes built into the shield machine during tunneling. However, even after synchronous grouting, the gap between the tunnel segments and the soil may still have poor filling density, leading to ineffective control of surface settlement or serious leakage in the tunnel lining. In such cases, secondary grouting is required to further supplement and strengthen the synchronous grouting, while also filling and reinforcing the surrounding ground. Secondary grouting uses dual-liquid grout as the grouting material, which needs to be prepared on-site. In existing technologies, it is usually carried out in the limited space at the tail of the shield. The transportation of materials and grouting efficiency will have a significant impact on shield construction as the tunnel excavation progresses. After grouting, it is also difficult to clean the grouting pipes and equipment in a timely and effective manner. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] To achieve these objectives and other advantages according to the present invention, a method for simultaneous grouting and secondary grouting in tunnel boring machines is provided, comprising the following steps:

[0005] S1. Erecting the grouting trolley: The grouting trolley is connected to the shield machine frame; the grouting trolley is equipped with a synchronous grouting fluid storage and mixing tank, a secondary grouting device, and a cleaning device.

[0006] S2. Preparation and transportation of synchronous grouting fluid: The synchronous grouting fluid is transported to the tail of the shield by a grouting truck and pumped into the shield machine's grout storage tank and the synchronous grouting fluid storage and mixing tank.

[0007] S3. Synchronous grouting: A synchronous grouting pipeline and synchronous grouting pump built into the shield tail are used. The synchronous grouting pump pumps the cement slurry in the shield machine's slurry storage tank into the synchronous grouting pipeline. Grouting is carried out through the synchronous grouting pipeline as the shield advances and the gap at the shield tail is formed. When the grouting pressure or grouting volume reaches the set value, synchronous grouting is stopped, and the synchronous grouting pipeline and synchronous grouting pump are cleaned by a cleaning device.

[0008] S4. Secondary grouting: Monitor the surface settlement and whether there are voids behind the lining of the pipe segments to determine whether secondary grouting is required; when secondary grouting is required, secondary grouting is performed in the grouting holes reserved on the corresponding pipe segments through the secondary grouting device; the grout pressure of the secondary grouting is greater than the sum of the static water pressure and soil pressure at the corresponding grouting point. When the grouting pressure reaches the set value, the secondary grouting is stopped, and the secondary grouting device is cleaned through a cleaning device.

[0009] Preferably, the synchronous grouting pipeline is configured as six lines, with four of the six grouting points arranged symmetrically about the center of the shield tail segment, and the remaining two arranged on the left and right sides of the top of the shield tail segment; each of the synchronous grouting pipelines is equipped with a pressure sensor and a flow meter at its injection end.

[0010] Preferably, during synchronous grouting, the grouting pressure is set to 0.15–0.3 MPa, and the grouting volume is set to 1.3–1.5 times the theoretical volume of the annular gap.

[0011] Preferably, the secondary grouting device includes a cement slurry mixing tank, a water glass storage tank, a mixing tank, and a secondary grouting head. The cement slurry mixing tank is used to prepare and store cement slurry and is connected to the mixing tank via a first pipeline. The water glass storage tank is used to store water glass solution and is connected to the mixing tank via a second pipeline. The mixing tank is used to store the mixed slurry of cement slurry and water glass and is connected to the secondary grouting head via a third pipeline. Grouting pumps are installed on the first pipeline, the second pipeline, and the third pipeline. Electronic flow meters are installed on the first pipeline and the second pipeline, and a pressure sensor is installed at the connection between the third pipeline and the secondary grouting head.

[0012] Preferably, the secondary grouting head includes a three-way connector, the first connector of which is connected to the third pipeline via a quick connector, the second connector is connected to a pressure relief valve, and the third connector is connected to the grouting end for injecting grout into the grouting hole.

[0013] Preferably, a material interception valve and a cleaning port are sequentially provided along the slurry flow direction on the pipeline connecting the synchronous grouting pump and the slurry storage tank of the tunnel boring machine, as well as on the third pipeline between the mixing tank and the corresponding grouting pump, and a sealing plug can be detachably connected to each of the cleaning ports.

[0014] Preferably, the cleaning device includes a water tank, which is connected to the cleaning port via an upper main pipeline, and a clean water pump is installed on the upper main pipeline; the grouting end of the synchronous grouting pipeline or the secondary grouting head is connected to the first branch pipeline.

[0015] Preferably, the cleaning device further includes a cleaning connector, a synchronous grouting fluid recovery mixing tank, and a dual grouting fluid recovery mixing tank; a clean water flow meter is installed on the upper main pipeline; the cleaning connector is a tee connector, with its first connector connected to the lower main pipeline, its second connector connected to the first branch pipeline, and its third connector connected to the second branch pipeline; the other end of the lower main pipeline is connected to the grouting end of the synchronous grouting pipeline or the secondary grouting head; ball valves are installed on both the first branch pipeline and the second branch pipeline; the other end of the second branch pipeline is connected to the synchronous grouting fluid recovery tank or the dual grouting fluid recovery tank.

[0016] Preferably, the synchronous grouting fluid storage and mixing tank, the cement slurry mixing tank, the mixing tank, the synchronous grouting fluid recovery and mixing tank, and the dual slurry recovery and mixing tank are all equipped with a mixing device.

[0017] Preferably, it also includes a control component, which includes a control unit and a display unit. The control unit receives data collected by each of the pressure sensors, each of the electronic flow meters, and the clean water flow meter through a data acquisition device. The control component is electrically connected to each of the stirring devices, each of the grouting pumps, the clean water pumps, and each of the ball valves. The display unit is connected to the control unit to display the operating status and operating parameters of each device.

[0018] The present invention has at least the following beneficial effects:

[0019] 1. The shield tunneling synchronous grouting and secondary grouting construction method provided by this invention combines synchronous grouting and secondary grouting for backfilling of tunnel segments, effectively filling the gaps in the shield tail construction and reinforcing the surrounding strata. Furthermore, a grouting trolley is erected at the shield tail, equipped with a synchronous grouting fluid storage and mixing tank, a cement slurry mixing tank, and a mixing tank for storing synchronous grouting fluid and preparing and storing the dual slurries for secondary grouting. This trolley can move forward with the shield machine frame without affecting shield machine construction. Secondary grouting can be performed at any time, and the length of the grouting pipeline can be fixed, saving time in transporting grouting equipment, reducing construction costs, and effectively improving construction efficiency.

[0020] 2. The shield tunneling synchronous grouting and secondary grouting construction method provided by the present invention involves mixing cement slurry and water glass solution in proportion on a grouting trolley through a cement slurry mixing tank, a water glass storage tank, and a mixing tank to obtain a double grout. The fully mixed double grout can effectively ensure the secondary grouting effect. Furthermore, when the double grout is not required, the cement slurry mixing tank can be directly connected to the secondary grouting head through a pipeline for grouting.

[0021] 3. The shield tunneling synchronous grouting and secondary grouting construction method provided by the present invention enables timely cleaning of the synchronous grouting pipeline, synchronous grouting pump and secondary grouting device by setting a cleaning device on the grouting trolley, and can also recycle the grout left in the grouting pipeline and grouting pump, avoiding a large amount of grout waste, reducing the cost of treating waste grout and the burden on shield slag discharge.

[0022] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the grouting trolley described in this invention;

[0024] Figure 2 This is a schematic diagram of the secondary grouting device described in this invention;

[0025] Figure 3 This is a schematic diagram of the cleaning device described in this invention; Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0027] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] like Figures 1-3 As shown, the present invention provides a method for simultaneous grouting and secondary grouting of a tunnel boring machine, comprising the following steps:

[0029] S1. Erecting the grouting trolley 200: The grouting trolley 200 is connected to the shield machine frame; the grouting trolley is equipped with a synchronous grouting fluid storage and mixing tank 500, a secondary grouting device, and a cleaning device.

[0030] S2. Preparation and transportation of synchronous grouting fluid: The synchronous grouting fluid is transported to the tail of the shield by a grouting truck and pumped into the shield machine's grout storage tank and the synchronous grouting fluid storage and mixing tank 500.

[0031] S3. Synchronous grouting: A synchronous grouting pipeline and synchronous grouting pump built into the shield tail are used. The synchronous grouting pump pumps the cement slurry in the shield machine's slurry storage tank into the synchronous grouting pipeline. Grouting is carried out through the synchronous grouting pipeline as the shield advances and the gap at the shield tail is formed. When the grouting pressure or grouting volume reaches the set value, synchronous grouting is stopped, and the synchronous grouting pipeline and synchronous grouting pump are cleaned by a cleaning device.

[0032] S4. Secondary grouting: Monitor the surface settlement and whether there are voids behind the lining of the pipe segments to determine whether secondary grouting is required; when secondary grouting is required, secondary grouting is performed in the grouting holes reserved on the corresponding pipe segments through the secondary grouting device; the grout pressure of the secondary grouting is greater than the sum of the static water pressure and soil pressure at the corresponding grouting point. When the grouting pressure reaches the set value, the secondary grouting is stopped, and the secondary grouting device is cleaned through a cleaning device.

[0033] In this technical solution, the grouting trolley 200, erected at the tail of the shield, provides a construction platform for secondary grouting. The grouting trolley 200 can be a conventionally used grouting trolley. Figure 1 The trolley structure shown includes a portal frame and wheels 230 mounted at the bottom of the portal frame. The portal frame includes symmetrically arranged working platforms 220 within the tunnel segments, and a top plate 210 mounted on top of the working platforms 220 to connect the two working platforms 220 into a single unit. The distance between the two working platforms 220 is sufficient for the passage of the battery-powered vehicle unit. A row of wheels 230 is respectively installed at the bottom of each of the two working platforms 220, which, under the action of a drive mechanism, move the portal frame, or connect the portal frame to the last section of the tunnel boring machine's frame via a traction rod, allowing it to advance together with the tunnel boring machine. The synchronous grouting fluid is prepared according to the designed mix ratio at a mixing station on the ground. It is then transported to the shield tail by grout transport vehicles and pumped into the shield machine's grout storage tank and the synchronous grouting fluid storage and mixing tank 500. The synchronous grouting fluid storage and mixing tank 500 acts as an intermediate storage station for the synchronous grouting fluid, making full use of the grouting trolley 200 to increase the storage capacity of the synchronous grouting fluid and reduce the frequency of transport by grout transport vehicles. The synchronous grouting fluid storage and mixing tank pumps the synchronous grouting fluid into the shield machine's grout storage tank through grouting pumps and pipelines. The synchronous grouting fluid comprises the following components: fine sand, cement, bentonite, fly ash, and water. Its main physical and mechanical properties should meet the following requirements: gel time of 6–10 hours, and solidified body strength: R7 ≥ 0.5 MPa, R28 ≥ 2.5 MPa.

[0034] During synchronous grouting, six synchronous grouting pipelines are set up. Of the six corresponding grouting points, four are symmetrically arranged about the center of the shield tail segment, and the other two are located on the left and right sides of the top of the shield tail segment. Synchronous grouting fluid is injected into the annular gap between the excavation diameter and the outer diameter of the segment through the synchronous grouting pipelines and synchronous grouting pumps at the shield tail, which improves the liquefiable soil layer, controls the stratum deformation, and enhances the tunnel's anti-buoyancy ability.

[0035] During synchronous grouting, to ensure effective filling of the circumferential voids while preventing deformation and damage to the segment structure due to grouting, the grouting pressure is set at 0.15–0.3 MPa, and the grouting volume is set at 1.3–1.5 times the theoretical volume of the circumferential gap. The synchronous grouting speed should be matched with the tunneling speed, and the average grouting speed should be determined based on the amount of grout to be completed for the current ring within the time it takes for the shield to complete one ring of tunneling.

[0036] The completion standard for synchronous grouting is controlled by dual indicators: grouting pressure and grouting volume. Grouting stops when either the grouting pressure or the grouting volume reaches a set value. To monitor the grouting pressure and volume, pressure sensors and flow meters are installed at the injection ends of each synchronous grouting pipeline. After grouting, the grouting effect is evaluated and checked based on the PQt curve, combined with the tunneling speed and deformation measurements of the lining, surface, and surrounding structures. If the requirements are met, the next grouting cycle begins; otherwise, supplementary grouting measures are implemented.

[0037] During shield tunneling, based on feedback from surface settlement monitoring and by detecting voids behind the tunnel lining segments, a comprehensive assessment is made to determine whether secondary grouting is necessary. Secondary grouting uses a dual-slurry mixture of cement slurry and water glass solution, with a 1:1 volume ratio. The water-cement ratio in the cement slurry is 1:0.8–1:1, and the volume ratio of water glass to water in the water glass solution is 1:1. The grout pressure for secondary grouting is greater than the sum of the static water pressure and earth pressure at the corresponding grouting point. Ideally, the secondary grouting pressure is generally 1.1–1.2 times the static earth pressure. Depending on the shield machine's advancing speed, secondary reinforcement grouting is performed approximately 5–7 rings after the tunnel segment exits the shield tail, based on ground monitoring data. Secondary reinforcement grouting should first be applied to the upper half of the tunnel segment where voids may exist to prevent segment floating. When the grouting pressure reaches the set value, secondary grouting is stopped, and the secondary grouting device is cleaned using a cleaning system.

[0038] Specifically, such as Figure 1 and Figure 2As shown, the secondary grouting device includes a cement slurry mixing tank 310, a water glass storage tank 340, a mixing tank 330, and a secondary grouting head 320. The cement slurry mixing tank 310 is used to prepare and store cement slurry and is connected to the mixing tank 330 through a first pipeline 311. The water glass storage tank 340 is used to store water glass solution and is connected to the mixing tank 330 through a second pipeline 341. The mixing tank 330 is used to store the mixed cement slurry and water glass solution and is connected to the secondary grouting head 320 through a third pipeline 331. Grouting pumps are installed on the first pipeline 311, the second pipeline 341, and the third pipeline 331. Electronic flow meters are installed on the first pipeline 311 and the second pipeline 341, and a pressure sensor is installed at the connection between the third pipeline 331 and the secondary grouting head.

[0039] When preparing the dual grout, equal amounts of cement and water are first injected into the cement grout mixing tank 310 and stirred to obtain cement grout. This cement grout is then transported to the mixing tank 330 via a grouting pump on the first pipeline 311. Simultaneously, a water glass solution is transported to the mixing tank 330 via a grouting pump on the second pipeline 341. The volumes of the cement grout and water glass solution transported to the mixing tank 330 are monitored by electronic flow meters on the first and second pipelines 311, respectively, to control their mixing ratio. The cement grout and water glass solution are mixed in the mixing tank 330 to obtain the dual grout, which is then transported to the secondary grouting head 320 via a grouting pump on the third pipeline 331 and injected into the grouting hole to be grouted. The corresponding grouting pressure is monitored by a pressure sensor. This secondary grouting device enables efficient and precise preparation of the dual grout within the confined space of the tunnel, improving the efficiency of secondary grouting. When dual grouting is not required, the first pipeline 311 can be directly connected to the secondary grouting head 320. Alternatively, multiple branch pipelines can be established at the third pipeline 331 and connected to multiple secondary grouting heads respectively to achieve simultaneous grouting at multiple grouting points.

[0040] The secondary grouting head 320 includes a three-way connector 322. The first connector of the three-way connector 322 is connected to the third pipeline 331 via a quick connector. The second connector is connected to a pressure relief valve 323, and the third connector is connected to the grouting end 322 for injecting grout into the grouting hole. After the secondary grouting is completed, the corresponding grouting pump is turned off, and the pressure relief valve 323 is opened to release pressure. The grouting end 322 can be selected from grouting pipes adapted to the grouting hole.

[0041] To facilitate cleaning of the synchronous grouting pipeline, the synchronous grouting pump, and the secondary grouting equipment, a material shut-off valve 432 and a cleaning port 431 are sequentially installed along the grout flow direction on the pipeline connecting the synchronous grouting pump to the tunnel boring machine's grout storage tank and on the third pipeline 331 between the mixing tank 330 and the corresponding grouting pump. Each cleaning port 431 can be detachably connected to a sealing plug. During grouting, the sealing plug closes the cleaning port 431; after grouting, when cleaning is required, the sealing plug is removed, and the cleaning device is connected to the corresponding cleaning port 431. Preferably, the sealing plug and the cleaning port 431, as well as the cleaning device and the cleaning port 431, can be connected by threads. The material shut-off valve 430 can be a ball valve.

[0042] The cleaning device includes a water tank 410, which is connected to the cleaning port 430 via an upper main pipeline 420. A ball valve 421 is installed on the upper main pipeline 420. The grouting end of the synchronous grouting pipeline or the secondary grouting head 320 is connected to the first branch pipeline 460.

[0043] When cleaning the synchronous grouting pipeline and synchronous grouting pump, connect the main pipeline 420 to the cleaning port 431 on the pipeline between the synchronous grouting pump and the tunnel boring machine's grout storage tank, close the corresponding material shut-off valve 432, and simultaneously connect the first branch pipeline 460 to the grouting end of the synchronous grouting pipeline. Open the ball valve 421 and the synchronous grouting pump, and pump the clean water in the water tank 410 into the synchronous grouting pump and the synchronous grouting pipeline through the cleaning port 430, and discharge it from the first branch pipeline 460. When one synchronous grouting pump corresponds to multiple synchronous grouting pipelines, multiple first branch pipelines 460 are set accordingly.

[0044] When cleaning the secondary grouting device, connect the cleaning port 431 on the third pipeline between the main pipeline 420 and the mixing tank 330 and the corresponding grouting pump, close the corresponding material shut-off valve 432, and simultaneously connect the first branch pipeline 460 to the grouting end 322 of the secondary grouting head 320. Open the ball valve 421 and the grouting pump on the third pipeline to pump clean water from the water tank 410 into the grouting pump and the secondary grouting head 320 through the cleaning port 430, and discharge it from the first branch pipeline 460. Similarly, when one grouting pump corresponds to multiple secondary grouting heads 320, multiple first branch pipelines 460 are correspondingly set up.

[0045] Considering that cleaning the grouting equipment will result in a certain degree of grout waste, different grout recovery devices are installed in the cleaning device. Specifically, such as... Figure 3As shown, the cleaning device also includes a cleaning connector 450, a synchronous grouting fluid recovery mixing tank, and a dual grouting fluid recovery mixing tank; a clean water flow meter 422 is installed on the upper main pipeline 420; the cleaning connector 450 is a tee connector, with its first connector connected to the lower main pipeline 440, its second connector connected to the first branch pipeline 460, and its third connector connected to the second branch pipeline 470; the other end of the lower main pipeline 440 is connected to the grouting end of the synchronous grouting pipeline or the secondary grouting head 320; ball valves 461 and 471 are installed on both the first branch pipeline 460 and the second branch pipeline 470; the other end of the second branch pipeline 470 is connected to the synchronous grouting fluid recovery tank or the dual grouting fluid recovery tank.

[0046] When cleaning the synchronous grouting pipeline or secondary grouting device, connect the lower main pipeline 440 to the corresponding cleaning port 431, close the corresponding material shut-off valve 432, connect the second branch pipeline 470 to the synchronous grouting liquid recovery tank or the dual grout recovery tank, open the ball valve 471 and the corresponding grouting pump, monitor the zero clean water volume pumped in by the clean water flow meter 422, and close the corresponding grouting pump and ball valve 471 after the set volume is reached to complete one cleaning cycle. The synchronous grouting fluid or dual grouting fluid in the grouting pump and grouting pipeline, along with the pumped clean water, enters the synchronous grouting fluid recovery tank or dual grouting fluid recovery tank. After all synchronous grouting pipelines or all secondary grouting heads have been rinsed with an equal amount of clean water, according to the total water volume monitored by the clean water flow meter, an appropriate amount of dry-mixed mortar or water glass and cement is added to the synchronous grouting fluid recovery tank or dual grouting fluid recovery tank according to the mixing ratio. The mixture is stirred in the synchronous grouting fluid recovery tank or dual grouting fluid recovery tank to obtain the synchronous grouting fluid or dual grouting fluid to be tested. After passing the test, it is input into the synchronous grouting fluid storage mixing tank or the mixing mixing tank through the pipeline and grouting pump. After the first cleaning, the ball valve 471 on the second branch pipeline 470 is closed, and the ball valve 461 and the corresponding grouting pump are opened to perform a second cleaning of the grouting pipeline and grouting pump. The waste liquid is discharged into the shield tunnel sewage pipeline through the first branch pipeline 460.

[0047] To prevent the grout from solidifying or segregating, the synchronous grouting fluid storage and mixing tank, the cement slurry mixing tank, the mixing tank, the synchronous grouting fluid recovery and mixing tank, and the dual grout recovery and mixing tank are all equipped with a mixing device to continuously agitate the grout. The mixing device can be a conventional mixing device consisting of a mixing motor, a mixing shaft, and mixing blades.

[0048] In another embodiment, to achieve automatic control of synchronous grouting and secondary grouting processes, a control component is further included, comprising a control unit and a display unit. The control unit receives data collected by the pressure sensors, electronic flow meters, and clean water flow meters via a data acquisition device. The control component is electrically connected to the stirring devices, grouting pumps, clean water pumps, and ball valves. The display unit is connected to the control unit to display the operating status and parameters of each device. The control unit can be a PLC controller. During grouting, the control unit receives data collected by the pressure sensors and electronic flow meters and controls the opening and closing of the grouting pumps and the material shut-off valves. During cleaning, it controls the opening and closing of the grouting pumps, ball valves, and material shut-off valves based on the data monitored by the clean water flow meters.

[0049] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for simultaneous grouting and secondary grouting in shield tunneling, characterized in that, Includes the following steps: S1. Erecting the grouting trolley: The grouting trolley is connected to the shield machine frame; the grouting trolley is equipped with a synchronous grouting fluid storage and mixing tank, a secondary grouting device, and a cleaning device. S2. Preparation and transportation of synchronous grouting fluid: The synchronous grouting fluid is transported to the tail of the shield by a grouting truck and pumped into the shield machine's grout storage tank and the synchronous grouting fluid storage and mixing tank. S3. Synchronous grouting: A synchronous grouting pipeline and synchronous grouting pump built into the shield tail are used. The synchronous grouting pump pumps the cement slurry in the shield machine's slurry storage tank into the synchronous grouting pipeline. Grouting is carried out through the synchronous grouting pipeline as the shield advances and the gap at the shield tail is formed. When the grouting pressure or grouting volume reaches the set value, synchronous grouting is stopped, and the synchronous grouting pipeline and synchronous grouting pump are cleaned by a cleaning device. S4. Secondary grouting: Monitor the surface settlement and whether there are voids behind the lining of the pipe segments to determine whether secondary grouting is required; when secondary grouting is required, secondary grouting is performed in the grouting holes reserved on the corresponding pipe segments through the secondary grouting device; the grout pressure of the secondary grouting is greater than the sum of the static water pressure and soil pressure at the corresponding grouting point; when the grouting pressure reaches the set value, the secondary grouting is stopped, and the secondary grouting device is cleaned through a cleaning device. The secondary grouting device includes a cement slurry mixing tank, a water glass storage tank, a mixing tank, and a secondary grouting head. The cement slurry mixing tank is used to prepare and store cement slurry and is connected to the mixing tank via a first pipeline. The water glass storage tank is used to store water glass solution and is connected to the mixing tank via a second pipeline. The mixing tank is used to store the mixed slurry of cement slurry and water glass and is connected to the secondary grouting head via a third pipeline. Grouting pumps are installed on the first pipeline, the second pipeline, and the third pipeline. Electronic flow meters are installed on the first pipeline and the second pipeline, and a pressure sensor is installed at the connection between the third pipeline and the secondary grouting head. On the pipeline connecting the synchronous grouting pump and the grout storage tank of the tunnel boring machine, and on the third pipeline between the mixing tank and the corresponding grouting pump, a material interception valve and a cleaning port are sequentially installed along the grout flow direction. Each cleaning port can be detachably connected with a sealing plug. The cleaning device includes a water tank, which is connected to the cleaning port via an upper main pipeline. A clean water pump is installed on the upper main pipeline. The grouting end of the synchronous grouting pipeline or the secondary grouting head is connected to the first branch pipeline. The cleaning device also includes a cleaning connector, a synchronous grouting fluid recovery mixing tank, and a dual grouting fluid recovery mixing tank; a clean water flow meter is installed on the upper main pipeline; the cleaning connector is a tee connector, with its first connector connected to the lower main pipeline, its second connector connected to the first branch pipeline, and its third connector connected to the second branch pipeline; the other end of the lower main pipeline is connected to the grouting end of the synchronous grouting pipeline or the secondary grouting head; ball valves are installed on both the first branch pipeline and the second branch pipeline; the other end of the second branch pipeline is connected to the synchronous grouting fluid recovery tank or the dual grouting fluid recovery tank.

2. The shield tunneling synchronous grouting and secondary grouting construction method as described in claim 1, characterized in that, The synchronous grouting pipeline is configured with six lines. Of the six grouting points, four are symmetrically arranged about the center of the shield tail segment, and the other two are located on the left and right sides of the top of the shield tail segment. Each synchronous grouting pipeline is equipped with a pressure sensor and a flow meter at its injection end.

3. The shield tunneling synchronous grouting and secondary grouting construction method as described in claim 2, characterized in that, During synchronous grouting, the grouting pressure is set at 0.15–0.3 MPa, and the grouting volume is set at 1.3–1.5 times the theoretical volume of the annular gap.

4. The shield tunneling synchronous grouting and secondary grouting construction method as described in claim 1, characterized in that, The secondary grouting head includes a three-way connector. The first connector of the three-way connector is connected to the third pipeline via a quick connector. The second connector is connected to a pressure relief valve. The third connector is connected to the grouting end for injecting grout into the grouting hole.

5. The shield tunneling synchronous grouting and secondary grouting construction method as described in claim 1, characterized in that, The synchronous grouting fluid storage and mixing tank, the cement slurry mixing tank, the mixing tank, the synchronous grouting fluid recovery and mixing tank, and the dual slurry recovery and mixing tank are all equipped with mixing devices.

6. The shield tunneling synchronous grouting and secondary grouting construction method as described in claim 5, characterized in that, It also includes a control component, which includes a control unit and a display unit. The control unit receives data collected by each of the pressure sensors, each of the electronic flow meters, and the clean water flow meter through a data acquisition device. The control unit is electrically connected to each of the stirring devices, each of the grouting pumps, the clean water pumps, and each of the ball valves. The display unit is connected to the control unit and is used to display the operating status and operating parameters of each device.

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