Construction method for pressure - maintained opening of slurry shield in muddy water at the river bottom with solidified slurry flow state

Abstract

The present invention relates to a construction method for pressure - chamber opening with slurry fluidization and solidification at the bottom of a river, which is used to adapt to the situation where a collapse arch is formed above during the tunneling construction of a shield machine under the river surface. When the machine stops, a pressure - chamber opening operation of the shield machine is carried out. The pressure - chamber opening construction method includes the following steps: S1. Preparation work; S2. Mud replacement in the mud chamber, including: S2.1. Establishing a mud replacement path; S2.2. Replacing the mud in the chamber in two stages; S3. Slurry fluidization and solidification; S4. Pressure - chamber opening. In this application, based on the multiphase flow slurry in the mud chamber when the slurry shield stops, it is replaced with viscous slurry, and through fluidization and solidification, a solidified soil with moderate strength, self - compacting property, stable volume and good impermeability is formed. Then, the pressure - chamber opening operation can be directly carried out, increasing the opening efficiency and realizing rapid chamber cleaning.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering construction, and particularly refers to a construction method for pressure - chamber opening with slurry fluidization and solidification of a muddy - water shield under a river bottom. Background Technique

[0002] Pressure - chamber opening is an effective means to solve problems such as cutter wear and stagnant discharge in the chamber during muddy - water shield construction. Gas preservation in the soil layer and stability of the excavation face are two key factors for the smooth progress of pressure - chamber opening. Generally, a traditional bentonite slurry is used to penetrate and form a mud film, and when necessary, a diaphragm reinforcement method is supplemented to achieve pressure - chamber opening. However, for the fractured and permeable soft - upper - hard - lower strata with criss - cross fissures developed under the river bottom, due to the existence of a caving arch at the top of the shield machine, the traditional method of establishing a mud film mostly ends in failure, and finally, only the method of filling the chamber can be adopted for treatment.

[0003] In actual construction, the mortar - filling method for the chamber has high strength and is difficult to clean, and its permeability is not good, resulting in a long time for chamber opening; the Hengdun mud - filling method for the chamber has a complex mixing process, high viscosity and is not easy to clean, and high cost; both have the problem of low chamber - opening efficiency and cannot achieve rapid chamber cleaning. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a construction method for pressure - chamber opening with slurry fluidization and solidification of a muddy - water shield under a river bottom, so as to solve the problem of low chamber - opening efficiency in the existing pressure - chamber opening methods.

[0005] To achieve the above - mentioned purpose, the present invention provides a construction method for pressure - chamber opening with slurry fluidization and solidification of a muddy - water shield under a river bottom, which is used to adapt to the situation where a caving arch is formed in the upper part during the tunneling construction of the shield machine under the river surface. When the machine stops, a pressure - chamber opening operation of the shield machine is carried out. The pressure - chamber opening construction method includes the following steps:

[0006] S1. Preparation work;

[0007] S2. Mud - water replacement in the mud chamber, including:

[0008] S2.1. Establishing a mud - water replacement path: Provide a motor - driven vehicle and establish a replacement path from the freshly - mixed slurry prepared on the ground - motor - driven vehicle - synchronous grouting barrel - mud chamber - waste slurry treatment system;

[0009] S2.2. Two - stage replacement of the mud and water in the chamber: Use viscous slurry and plugging - type slurry successively according to the established mud - water replacement path for two - stage mud - water replacement in the mud chamber until the mud - water index discharged from the mud chamber meets the standard and then stop;

[0010] S3. Slurry fluidization and solidification, including:

[0011] S3.1. Establish a curing agent mixing system: Provide a curing agent mixing device, which is transported into the site by a motorized vehicle. The slurry outlet of the curing agent mixing device is connected to the synchronous grouting bucket through a third slurry outlet pipe, and the slurry return port of the curing agent mixing device is connected to the mud replacement outlet of the slurry sump through a return pipeline to form a recyclable path.

[0012] S3.2. Replace the fluid soil in the slurry sump: The curing agent mixing device mixes the curing agent. At the same time, it is sent into the slurry sump along the mud replacement path through the synchronous grouting bucket and mixed with the internal mud, and the fluid soil slurry formed in the sump after curing flows back to the curing agent mixing device.

[0013] S3.3. Evaluate the indicators of the fluid soil slurry in the sump: Release the fluid soil slurry in the sump at the mud replacement outlet of the slurry sump at regular intervals for measurement. If the requirements are not met, continue to add the curing agent; if the requirements are met, stop.

[0014] S3.4. Gradually pressurize and infiltrate: Gradually pressurize the slurry sump to make the fluid soil slurry in the sump infiltrate out to form a caving arch on the shield machine. During this period, timely supplement the fluid soil slurry in the sump until the caving arch on the shield machine is filled and compacted.

[0015] S4. Open the chamber under pressure.

[0016] By adopting this technical solution, based on the multiphase flow slurry in the slurry sump when the slurry shield machine stops, it is replaced with viscous slurry, and through fluid curing, a cement stabilized soil with moderate strength, self-compacting, stable volume and good impermeability is formed. Then, the operation of opening the chamber under pressure can be directly carried out, increasing the chamber opening efficiency and realizing rapid chamber cleaning.

[0017] Further, the preparatory work in step S1 includes the following steps:

[0018] S1.1. Ring grouting: Seal the tail of the shield machine and inject Clayzyme through the grouting holes around the shield machine to wrap the shield machine shell.

[0019] S1.2. Clean the chamber under pressure: Enter the air cushion chamber and the slurry sump under pressure, and remove the foreign matters accumulated at the bottom of the air cushion chamber and the slurry sump.

[0020] S1.3. Close the front gate: Close the front gate to isolate the air cushion chamber and the slurry sump.

[0021] Further, the preparatory work in step S1 also includes the following steps:

[0022] S1.4. Regularly maintain the mud circulation system under normal pressure: Except for the slurry sump, do a good job in dredging the mud discharge part of the shield machine circulation system under normal pressure conditions.

[0023] Further, the preparatory work in step S1 also includes the following steps:

[0024] S1.5. Set the function of reverse flushing the pipeline: Install multiple second ball valves on the pipelines inside the shield machine. A first pressure gauge is set on the second ball valve. The numerical values of adjacent first pressure gauges are used to determine whether the pipeline between adjacent second ball valves is blocked, and at the same time, it provides a basis for reverse flushing and dredging the pipeline.

[0025] The reverse flushing and dredging of the pipeline are realized by a water tank, an extrusion pump, a soil box and connecting pipelines. After a locally blocked pipeline appears and is determined in the pipelines inside the shield machine, under the action of the connecting pipelines, a reverse flushing path of water tank - extrusion pump - second ball valve of the pipeline inside the shield machine - blocked pipeline - second ball valve of the pipeline inside the shield machine - soil box is formed, and reverse flushing and dredging are realized by starting the extrusion.

[0026] Further, during the step S3.4 of graded pressure penetration, it also includes the filling detection of the caving arch.

[0027] The filling detection of the caving arch includes driving a filling detector from the river surface drilling platform to a safe distance above the caving arch, performing the filling detection inside the caving arch during the process of graded pressure penetration, pulling out the filling detector after ensuring that the caving arch is filled densely, and at the same time grouting to fill the channel formed by the filling detector.

[0028] Further, the pressure - maintained opening of the chamber in step S4 includes the following steps:

[0029] S4.1. Confirm the opening conditions: After the strength of the solidified soil formed by the solidification of the fluid soil slurry in the chamber reaches the standard, open the fourth ball valves at different parts of the breastplate of the slurry chamber to observe the water seepage volume. If the water seepage volume meets the requirements, the opening conditions are satisfied.

[0030] S4.2. Clean the solidified soil in different areas: Workers enter the slurry chamber by increasing the pressure in the personnel chamber, clean the solidified soil in the order of slurry chamber - cutter box - spoke opening - panel, and then check the cutters and replace them.

[0031] S4.3. Resume pushing after completion: Workers return to the personnel chamber to reduce the pressure, and at the same time, use fresh slurry to raise the internal liquid level of the slurry chamber through the mud displacement path. After the workers reduce the pressure and leave the chamber, the shield machine resumes pushing.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. Based on the multiphase flow slurry in the slurry chamber when the slurry shield machine stops, it is replaced with a viscous slurry, and through fluid solidification, a solidified soil with moderate strength, self - compacting, stable volume and good impermeability is formed. Then, the pressure - maintained opening operation of the chamber can be directly carried out, increasing the opening efficiency and realizing rapid chamber cleaning.

[0034] 2. By setting a caving arch filling detector on the river surface, the solidified soil fills the caving arch densely, effectively supporting the upper part of the tunnel and preventing soil loss. Finally, the pressure - maintained opening process is optimized to improve the opening efficiency. Brief Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the construction process of the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0036] Figure 2 It is a schematic diagram of the actual working condition of the shield machine in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0037] Figure 3 It is a schematic diagram of the tail - shield anti - leakage device in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0038] Figure 4 It is a front - view and side - view schematic diagram of the steel blank flange seal in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0039] Figure 5 It is a schematic diagram of the reverse - washing process in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0040] Figure 6 It is a schematic diagram of the muddy - water replacement path in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0041] Figure 7 It is a schematic diagram of the curing - agent mixing system in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0042] Figure 8 It is a schematic diagram of the setting of the third ball valve of the slurry mixing tank in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0043] Figure 9 It is a schematic diagram of the collapse - arch filling detector in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0044] Figure 10 It is a side - view and front - view schematic diagram of the regional cleaning in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0045] Figure 11 It is a front - view and side - view schematic diagram of the pressure - maintained path for the first - stage opening of the chamber in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0046] Figure 12 It is a schematic diagram of the distribution and variable - diameter end - connection of the rapid drainage channel in the construction method for pressure - maintained opening of the slurry - flow solidification in the muddy - water shield under the river bottom in the present invention;

[0047] Figure 13This is the front view and side view schematic diagram of the pressure maintenance path during the second-phase opening of the slurry flow state solidification and pressure maintenance construction method for the muddy water shield in the river bottom of the present invention.

[0048] Description of reference numerals: 1. Shield machine; 2. River surface; 3. Collapse arch; 4. Lenticular body; 5. Sponge strip; 6. Baffle; 7. Safety chain; 8. Boot plate; 9. Steel blanking plate; 10. Door frame; 11. Water stop strip; 12. Bolt; 13. Hoisting hole; 14. Steel handle; 15. First ball valve; 16. Fresh water tank; 17. Extrusion pump; 18. Soil box; 19. Connecting pipeline; 20. Motor vehicle; 21. Blocking pipeline; 22. Second ball valve; 23. First pressure gauge; 24. Fresh slurry prepared on the ground; 25. Synchronous grouting barrel; 26. Slurry inlet hole; 27. Mud chamber; 28. First air release valve; 29. Synchronous grouting pipe; 30. Sewage pipeline; 31. Filler port; 32. Shear pump; 33. Mixing slurry tank; 34. First slurry outlet pipe; 35. Second slurry outlet pipe; 36. Third slurry outlet pipe; 37. Gate valve; 38. Return pipeline; 39. Third ball valve; 40. Steel casing; 41. Sleeve valve pipe; 42. Steel cover; 43. Cutter head; 44. Cutter box; 45. Spoke opening; 46. Panel; 47. Air cushion chamber; 48. Connecting pipeline; 49. First area; 50. Chest plate; 51. Man chamber; 52. Second air release valve; 53. Balance chamber; 54. Special pipeline; 55. Self-operated control valve; 56. Drainage hose; 57. Reducing end; 58. Conical gasket; 59. Drainage port; 60. Second area; 61. Fourth ball valve. Detailed implementation manners

[0049] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0050] Please refer to the attached Figure 1 、 2 and 11. The present invention provides a construction method for slurry flow state solidification and pressure maintenance during the opening of a muddy water shield in the river bottom. The actual working condition is that a front gate is provided for the mud chamber 27 and the air cushion chamber 47 of the muddy water shield machine 1. The sludge discharge path is: mud chamber 27 - front gate - air cushion chamber 47 - grille - sludge discharge pipe inside the shield machine - sludge discharge pump - ground muddy water solid control system; the shield machine 1 together with the trolley has entered the river bottom, the cutter head is in the section of the lower broken moderately weathered rock layer and the upper weathered soil, a cavity of the collapse arch 3 has been formed above the shield machine 1, and the stones falling into the chamber have caused serious blockage of the sludge discharge path, resulting in the paralysis of the circulation system; the mud chamber 27 and the upper cavity are filled with pressurized multiphase flow slurry, and the collapse arch 3 has a tendency to further develop towards the river bottom riverbed, and even a lenticular body 4 is formed in the stratum. The pressure maintenance construction method during the opening of the chamber includes the following steps:

[0051] Step 1: Preparation work

[0052] 1.1. Ring grouting: Inject Kneadable Gel around the shield machine 1 through the grouting holes around the shield machine 1. The segments in the tail void are replenished with tail seal grease and anti-leakage devices are installed. After the segments are withdrawn from the tail void, cement-sodium silicate double-fluid slurry is injected.

[0053] Preferably, please refer to the appendix Figure 3 , the anti-leakage device consists of a sponge strip 5 and a baffle 6. The sponge strip 5 is stuffed into the gap between the outer arc surface of the segment and the inner arc surface of the tail void. The baffle 6 is placed between the end face of the segment and the boot plate 8 of the propulsion jack of the shield machine 1. The baffle 6 and the boot plate 8 are connected by a safety chain 7 to seal the end of the segment inside the shield body and prevent leakage from the tail void.

[0054] 1.2. Pressurized cleaning of the chamber: Pressurized air is introduced into the air-cushioned chamber 47 to remove hard foreign objects such as stones and broken cutter rings accumulated at the bottom of the slurry chamber 27 and the air-cushioned chamber 47, especially to clean the bottom of the front gate thoroughly to prevent the front gate from not closing tightly or local buckling of the front gate caused by punching foreign objects.

[0055] 1.3. Closing the front gate: Please further refer to the appendix Figure 4 , close the front gate to isolate the slurry chamber 27 from the air-cushioned chamber 47; and install a steel blanking plate 9 with a water-stop strip 11 from the air-cushioned chamber 47 to cut off the infiltration path between the slurry chamber 27 and the air-cushioned chamber 47;

[0056] Preferably, bolt holes are provided around the steel blanking plate 9 and an annular rubber water-stop strip 11 is installed. The steel blanking plate 9 and the door frame 10 of the front gate are connected by bolts 12, which further improves the sealing and isolation effect and enables entry into the air-cushioned chamber 47 under normal pressure; the installation of the steel blanking plate 9 is completed through the lifting hole 13; manual positioning and installation are assisted by a steel handle 14; the situation of the slurry chamber 27 is observed through the first ball valve 15 on the steel blanking plate 9.

[0057] 1.4. Maintenance of the mud circulation system under normal pressure: Except for the slurry chamber 27, dredging work is carried out on the mud discharge part of the circulation system under normal pressure working conditions, that is, to ensure that the mud discharge path from the front gate - air-cushioned chamber 47 - grille - mud discharge pipe inside the shield machine 1 - mud discharge pump - on-ground mud solid control is in a smooth state, so as to prepare for the subsequent re-pushing of the shield machine 1.

[0058] 1.5. Setting the pipeline reverse flushing function: Please further refer to the appendix Figure 5 , multiple second ball valves 22 are installed in the pipelines inside the shield machine 1. A first pressure gauge 23 is set on the second ball valve 22, which can judge the blockage position of the blocked pipeline 21 by monitoring the pressure change, and at the same time realize the function of pipeline reverse flushing and dredging;

[0059] Preferably, the reverse flushing and dredging function of the pipeline is realized by the water tank 16, the extrusion pump 17, the soil box 18 and the connecting pipeline 19. After the blocked position of the pipeline is determined, the reverse flushing and dredging is realized by the path of the water tank 16 - extrusion pump 17 - the second ball valve 22 of the pipeline in the shield machine 1 - the blocked pipeline 21 - the second ball valve 22 of the pipeline in the shield machine 1 - the soil box 18; this function can be used as a way to dredge the blocked pipeline in the subsequent steps; among them, the water tank 16 is located on the trolley of the shield machine 1, and the extrusion pump 17, the soil box 18 and the connecting pipeline 19 are installed on the motor vehicle 20, which can be conveniently moved in the section.

[0060] Step 2: Mud replacement in the mud chamber 27

[0061] 2.1. Establish the mud replacement path: Please refer to the appendix Figure 6 , the mud replacement path in the mud chamber 27 is the freshly prepared slurry 24 on the ground - the motor vehicle 20 - the synchronous grouting barrel 25 - the slurry inlet hole 26 - press into the mud chamber 27 - the first air release valve 28 releases the multiphase flow slurry in the mud chamber 27;

[0062] Preferably, the path from the synchronous grouting barrel 25 to the bottom of the mud chamber 27 is obtained by relocating the synchronous grouting pipe 29; the first air release valve 28 at the top of the mud chamber 27 is connected to the sewage pipeline 30, and the sewage pipeline 30 joins the waste slurry disposal system on the shield trolley.

[0063] 2.2. Replace the mud in the chamber in two stages: Through the above replacement path, replace the mud in the chamber with the viscous slurry prepared by mixing bentonite and polymer to replace the multiphase flow slurry in the mud chamber 27; the composition of the viscous slurry is: 1 m 3 of water is mixed with 25 kg of HS-1, 5 kg of HS-3, and 40 kg of bentonite. The consistency of the slurry released from the first air release valve 28 at the top in the first stage reaches 50 - 60 s and the specific gravity reaches 1.1;

[0064] Through the above replacement path, replace the mud in the chamber in the second stage with the plugged slurry to replace the viscous slurry; on the basis of the viscous slurry, add 100 kg of heavy calcium powder and 5 kg of plugging agent per 1 m 3 to prepare the plugged slurry. The consistency of the slurry released from the first air release valve 28 at the top in the second stage reaches 180 s, the specific gravity reaches 1.25, and the sand content < 1.5%.

[0065] Step 3: Solidify the mud flow state

[0066] 3.1. Establish the curing agent mixing system: Please further refer to the appendix Figure 7, the provided curing agent mixing system formed by the curing agent mixing equipment carried on the motor vehicle 20 of the shield machine 1 includes a material filling port 31, a shear pump 32, a slurry mixing tank 33, a synchronous grouting barrel 25, a first slurry outlet pipe 34, a second slurry outlet pipe 35, and a third slurry outlet pipe 36; the replaced slurry is contained in the slurry mixing tank 33, the curing agent is sucked from the material filling port 31 by the negative pressure principle, and the shear pump 32 sucks the replaced muddy water and the curing agent from the slurry mixing tank 33 through the first slurry outlet pipe 34 and shears and mixes them in the shear pump 32, and is conveyed to the slurry mixing tank 33 through the first slurry outlet pipe 34. When the fluid soil slurry meets the requirements, it is conveyed to the synchronous grouting barrel 25 through the third slurry outlet pipe 36; the switching between the second slurry outlet pipe 35 of the slurry mixing tank 33 and the third slurry outlet pipe 36 of the synchronous grouting barrel 25 is carried out through the gate valve 37 on the pipeline;

[0067] Preferably, the mixing amount of the curing agent is 24%; the fluid soil slurry replacement is carried out through the muddy water replacement path in step two, which is different from step two in that the slurry discharged from the first air release valve 28 returns to the slurry mixing tank 33 through the return pipeline 38;

[0068] Further, please refer to the appendix Figure 8 , a third ball valve 39 is provided on the upper, middle, and lower parts of the box body of the slurry mixing tank 33. During the mixing process of the fluid soil slurry, its indexes are detected every ten minutes. When the specific gravity of the fluid soil slurry reaches 1.4, it meets the requirements.

[0069] 3.2. Fluid soil replacement in the muddy water chamber 27: The fluid soil slurry replacement in the muddy water chamber is carried out by using the muddy water replacement path in step two. The difference is that the fluid soil slurry discharged from the first air release valve 28 returns to the slurry mixing tank 33 through the pipeline.

[0070] 3.3. Evaluate the indexes of the liquid soil slurry in the evaluation chamber: Rotate the cutter head 43 intermittently to mix the fluid soil in the muddy water chamber 27 evenly to avoid stratification and segregation; discharge the slurry from the second air release valve 52 at the top of the breastplate 50 for measurement. If it does not meet the requirements, return to step 3.2;

[0071] 3.4. Stepwise pressure penetration: Stepwise pressure penetration is carried out in four stages;

[0072] Further, the set value of the final penetration pressure in the above stepwise pressure is twice the pressure for opening the chamber under pressure, and the set value of the starting pressure of the stepwise pressure is the water and soil pressure at the current position of the shield machine 1. The stepwise pressure values in the four stages are linearly interpolated; the pressure is obtained by the air cushion chamber 47 through the connecting pipeline 48 connecting the air cushion chamber 47 and the muddy water chamber 27. During the pressure penetration process, pay attention to the liquid level of the fluid soil slurry in the muddy water chamber 27, and timely inject and supplement the fluid soil slurry through the slurry inlet hole 26 on the breastplate 50 of the muddy water chamber 27. Each stage of pressure penetration maintains the pressure for a certain period of time;

[0073] Further, staged pressure boosting and penetration are implemented in four stages. In the first stage, the pressure at the top of the slurry chamber 27 for pressure boosting and penetration is set to 3.0 - 3.5 bar, and the pressure is stabilized for 5 hours. In the second stage, the pressure at the top of the slurry chamber 27 for pressure boosting and penetration is set to 3.6 - 4.0 bar, and the pressure is stabilized for 10 hours. In the third stage, the pressure at the top of the slurry chamber 27 for pressure boosting and penetration is set to 4.0 - 4.5 bar, and the pressure is stabilized for 10 hours. In the fourth stage, the pressure at the top of the slurry chamber 27 for pressure boosting and penetration is set to 4.5 - 5.0 bar, and the pressure is stabilized for 10 hours.

[0074] Further, during the pressure stabilization process of pressure boosting and penetration in the above four stages, the cutter head 43 is continuously rotated slightly, and the pressure fluctuation at the top of the cutting opening is kept stable during the pressure boosting process.

[0075] 3.5. Detection of the filling of the caving arch 3: A caving arch 3 filling detector is set on the river surface to guide the solidified soil formed by the solidification of the flowing soil to densely fill the caving arch 3.

[0076] Further, please refer to the appendix Figure 9 During the staged pressure boosting and penetration, the above caving arch 3 filling detector is set. The caving arch 3 filling detector is driven through the drilling platform on the river surface 2 above the boundary of the caving arch 3. The provided caving arch 3 filling detector consists of a large-diameter steel casing 40 and a small-diameter sleeve valve pipe 41, and a steel cover 42 and a pressure gauge are provided at the top of the steel casing 40. During the staged pressure boosting and penetration process, the value of the pressure gauge at the top of the steel casing 40 is observed. After the pressure rises and stabilizes, the steel cover 42 is opened, and it is observed that the flowing solidified slurry enters the steel casing 40 to verify that the caving arch 3 has been densely filled.

[0077] Further, after the caving arch 3 is densely filled, the large-diameter through-hole steel casing 40 is first pulled out, and then the small-diameter sleeve valve pipe 41 is retracted and grouted while retracting to densely fill the formation lens body 4 and the drilling channel of the caving arch 3 detector.

[0078] Step 4: Opening the chamber under pressure

[0079] 4.1. Confirmation of chamber opening conditions: When the strength of the solidified soil specimen cured under the same conditions ≥ 0.6 MPa, the fourth ball valve 61 at different parts of the breastplate 50 is opened to observe the water seepage volume. If the water seepage volume is less than 1 m 3 / d, the chamber opening conditions are met; the solidified soil specimen cured under the same conditions is prepared from the flowing solidified slurry meeting the indexes in the slurry mixing tank 33.

[0080] 4.2. Cleaning the solidified soil in different areas: Please refer to the appendix Figure 10 , formulate the principle of cleaning in different areas, clean the flowing solidified soil in the order of the slurry chamber 27 - cutter box 44 - spoke opening 45 - panel 46, then check the cutter head 43 and replace the cutters, clean the slurry chamber 27 from top to bottom, clean the cutter box 44 from top to bottom, clean the spoke opening 45 from top to bottom, and finally clean the panel 46 from top to bottom.

[0081] 4.3. First-stage opening of the chamber: Please refer to the appendix Figure 11 . When the slurry chamber 27 is filled with solidified soil and the connecting pipeline 48 between the air-cushion chamber 47 and the slurry chamber 27 is blocked, the first-stage opening of the chamber is before the connecting pipeline 48 between the air-cushion chamber 47 and the slurry chamber 27 is dredged; to clean the first area 49, dredge the second air-release valve 52 on the breastplate 50 of the shield machine 1 and above the personnel chamber 51 and the balance chamber 53 inside the personnel chamber 51 leading to the slurry chamber 27, and connect the air-cushion chamber 47 and the second air-release valve 52 with a special pipeline 54; when pressurizing and depressurizing the personnel chamber 51, manual operation with an independent air supply air compressor is used for pressure control. When the balance chamber 53 is opened, the personnel chamber 51 and the slurry chamber 27 are connected, and when the balance chamber 53 is closed, the personnel chamber 51 can be independently pressurized and depressurized; the chamber door of the slurry chamber 27 can be opened, and when the chamber door is opened, the opening pressure is controlled through the path of the self-acting control valve 55 - air-cushion chamber 47 - second air-release valve 52 - slurry chamber 27 - personnel chamber 51; when the chamber door is closed, a path of the self-acting control valve 55 - air-cushion chamber 47 - second air-release valve 52 - slurry chamber 27 is established to independently maintain the pressure of the slurry chamber 27; and a fast drainage channel 1 from the slurry chamber 27 to the bottom of the personnel chamber 51 is established.

[0082] For further reference to the appendix Figure 12 . Preferably, the path of the fast drainage channel 1 is from the slurry chamber 27 to the bottom of the personnel chamber 51, which consists of a drainage hose 56, a reduced-diameter end 57, and a conical sealing gasket 58. The reduced-diameter end 57 of the drainage hose 56 is placed in the accumulated water in the slurry chamber 27, and the other reduced-diameter end 57 is sleeved with a conical sealing gasket 58 and inserted into the bottom drainage port 59 of the personnel chamber 51. The conical sealing gasket 58 seals the air leakage channel between the reduced-diameter end 57 and the bottom drainage port 59; during the drainage process, the water level change in the chamber must be closely monitored to prevent the reduced-diameter end 57 from leaking out of the water surface, and the bottom drainage port 59 of the personnel chamber 51 should be closed in a timely manner to prevent air leakage in the slurry chamber 27 due to drainage.

[0083] 4.4. Second-stage opening of the chamber: After the connecting pipeline 48 between the air-cushion chamber 47 and the slurry chamber 27 is dredged, that is, the second-stage opening of the chamber enters the normal working state. To clean the second area 60, when the chamber door of the personnel chamber 51 is opened, the pressure is controlled through the system of the self-acting control valve 55 - air-cushion chamber 47 - connecting pipeline 48 - slurry chamber 27 - personnel chamber 51; when the chamber door of the personnel chamber 51 is closed, a path of the self-acting control valve 55 - air-cushion chamber 47 - connecting pipeline 48 - slurry chamber 27 is established to maintain the pressure of the slurry chamber 27; after the fourth ball valve 61 on the breastplate 50 is dredged, a fast drainage channel is established using the slurry chamber 27 - fourth ball valve 61.

[0084] 4.5. Re-pushing after completion: After cleaning by opening the chamber in stages, open the front gate, close the door of the personnel chamber 51, then the personnel enter the personnel chamber 51 for decompression, and at the same time, the liquid level is raised with fresh slurry. After the personnel decompress and leave the chamber, the shield machine 1 is re-pushed.

[0085] The present invention has been described in detail with reference to the embodiments accompanied by drawings. Those of ordinary skill in the art can make various variations to the present invention based on the above description. Therefore, certain details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope defined in the appended claims.

Claims

1. A construction method for pressure - maintaining opening of the slurry - flow - state solidification in the muddy water shield under the river bottom, which is used to adapt to the situation of the formation of a caving arch in the upper part during the tunneling construction of the shield machine under the river surface, and the pressure - maintaining opening operation of the shield machine is carried out during shutdown. It is characterized in that, The construction method for opening the chamber under pressure includes the following steps: S1. Preparation work; S2. Mud replacement in the mud chamber, including: S2.

1. Establishing a mud replacement path: Provide a motorized vehicle, and establish a replacement path from the freshly mixed slurry prepared on the ground - motorized vehicle - synchronous grouting barrel - mud chamber - waste slurry treatment system; S2.

2. Replacing the mud in the chamber in two stages: Use viscous slurry and plugging slurry successively according to the established mud replacement path to conduct two mud replacements in the mud chamber until the mud index discharged from the mud chamber meets the standard and then stop; S3. Solidifying the mud flow state, including: S3.

1. Establishing a curing agent mixing system: Provide a curing agent mixing device, which is transported into the chamber by a motorized vehicle. The outlet of the curing agent mixing device is connected to the synchronous grouting barrel through a third slurry outlet pipe, and the return slurry port of the curing agent mixing device is connected to the mud replacement outlet of the mud chamber through a return pipeline to form a recyclable path; S3.

2. Replacing the flowing soil in the mud chamber: The curing agent mixing device mixes the curing agent, and at the same time, it is sent into the mud chamber along the mud replacement path through the synchronous grouting barrel to mix with the internal mud, and the flowing soil slurry formed by curing flows back to the curing agent mixing device; S3.

3. Evaluating the index of the flowing soil slurry in the chamber: Release and measure the flowing soil slurry in the mud chamber at the mud replacement outlet of the mud chamber at regular intervals. If it does not meet the requirements, continue to add the curing agent. If it meets the requirements, stop; S3.

4. Gradually pressurizing and infiltrating: Gradually pressurize the mud chamber to make the flowing soil slurry in the chamber seep out to form a caving arch on the shield machine. During this period, timely supplement the flowing soil slurry in the mud chamber until the caving arch on the shield machine is filled densely; S4. Opening the chamber under pressure.

2. The method for constructing an open caisson with pressurization by solidifying the slurry flow state in muddy water shield tunneling at the river bottom according to claim 1, characterized in that, The preparation work in step S1 includes the following steps: S1.

1. Ring grouting: Seal the tail of the shield machine, and inject Knifewall around the shield machine through the grouting holes on the periphery of the shield machine; S1.

2. Cleaning the chamber under pressure: Enter the air cushion chamber and the mud chamber under pressure, and remove the foreign matters accumulated at the bottom of the air cushion chamber and the mud chamber; S1.

3. Closing the front gate: Close the front gate to isolate the air cushion chamber and the mud chamber.

3. The construction method for opening the chamber under pressure with solidified slurry flow regime of the muddy water shield under the river bottom according to claim 2, characterized in that, The preparation work in step S1 also includes the following steps: S1.

4. Maintaining the mud circulation system under normal pressure: Except for the mud chamber, do a good job in dredging the mud discharge part of the shield machine circulation system under normal pressure conditions.

4. The construction method for opening the chamber under pressure with solidified slurry flow regime of muddy water shield in the river bottom according to claim 3, characterized in that, The preparation work in step S1 also includes the following steps: S1.

5. Setting the function of reverse flushing the pipeline: Install a plurality of second ball valves on the pipelines inside the shield machine, and set a first pressure gauge on the second ball valves. Judge whether the pipeline between adjacent second ball valves is blocked by the values of adjacent first pressure gauges, and at the same time provide a basis for reverse flushing and dredging the pipeline; The reverse flushing and dredging of the pipeline are realized by a water tank, an extrusion pump, a soil box and connecting pipelines. After a locally blocked pipeline appears and is determined in the pipelines inside the shield machine, under the action of the connecting pipelines, a reverse flushing path of water tank - extrusion pump - second ball valve of the pipeline inside the shield machine - blocked pipeline - second ball valve of the pipeline inside the shield machine - soil box is formed, and reverse flushing and dredging are realized by starting the extrusion.

5. The construction method for opening the chamber under pressure with the fluidized state of the slurry of the muddy water shield at the bottom of the river according to claim 1, characterized in that, During the step of gradually pressurizing and infiltrating in S3.4, it also includes the filling detection of the caving arch; The filling detection of the caving arch includes driving a filling detector from the river surface drilling platform to a safe distance above the caving arch, and conducting the filling detection inside the caving arch during the process of step-by-step pressurized penetration. After ensuring that the caving arch is densely filled, the filling detector is pulled out, and at the same time, the channel formed by the filling detector is filled with grout.

6. The method for constructing an open chamber under pressure with solidified slurry flow regime for a muddy water shield in the river bottom, according to claim 5, is characterized in that, The pressure-assisted opening of the chamber in step S4 includes the following steps: S4.

1. Confirmation of opening conditions: After the strength of the solidified soil formed by the solidification of the fluid soil slurry in the chamber reaches the standard, open the fourth ball valve at different parts of the breastplate of the slurry chamber to observe the water seepage volume. If the water seepage volume meets the requirements, the opening conditions are satisfied; S4.

2. Clean the solidified soil in different areas: Workers enter the slurry chamber by increasing the pressure in the access chamber, clean the solidified soil in the order of the slurry chamber - cutter box - spoke opening - panel, and then check and replace the cutters; S4.

3. Re-push after completion: Workers return to the access chamber to reduce the pressure, and at the same time, raise the internal liquid level of the slurry chamber by using fresh slurry through the mud displacement path. After the workers leave the chamber under reduced pressure, the shield machine is re-pushed.

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