Tunneling method for solving spewing of shield tunneling machine by using balance shield mud

Abstract

The invention discloses a tunneling method for solving spewing of a shield tunneling machine through balance shield mud. The tunneling method comprises the following steps that the balance shield mud is pressed and injected to the outer side of a shield tunneling machine body; the balance shield mud is injected into the soil bin and in front of the cutterhead, and muck is replaced; after replacement is completed, continuously injecting balance shield mud into the soil bin in a small amount and multiple times, and performing graded pressurization; after the water gushing and air gushing gaps are blocked, pressure reduction and air and slurry replacement are conducted in the soil bin; injecting air into the bin, keeping the bin pressure, starting to rotate the cutterhead in situ, and uniformly discharging slag through a spiral unearthing device; and after the pressure in the bin is stable, tunneling parameters are configured according to the height of the slag level of the soil bin, and tunneling continues under the assistance of air pressure. By the adoption of the spiral unearthing device, the workability and the air tightness of the surrounding stratum can be improved, stable air pressure in the soil bin can be built, muck in the soil bin and in front of the cutter head can be improved, smooth and continuous deslagging of the spiral unearthing device is facilitated, meanwhile, the stratum air closing capacity needed by air pressure assistance is improved, and then the gushing problem is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and particularly to a tunneling method using balance slurry to solve shield machine gushing. Background Art

[0002] During the shield construction process, for rock formations with large buried depths, well-developed fissure water, and water-rich and airtight composite formations, using air pressure-assisted tunneling can effectively reduce the shield tunneling load, repel groundwater, prevent "gushing", and improve tunneling efficiency. However, if the top of the shield machine is in deep buried rock formations with well-developed fissure water, water-rich sand layers, and pebble layers, due to the low airtightness and insufficient workability of the muck in such formations, it is impossible to smoothly and effectively establish a stable air pressure in the soil chamber during tunneling, resulting in the inability to maintain the stability of the working face. At the same time, it is impossible to use the air pressure-assisted tunneling mode for tunneling, increasing the shield tunneling load while reducing tunneling efficiency. Therefore, the shield machine air pressure-assisted tunneling method based on improving the "workability" and "airtightness" of the surrounding strata of the shield machine with balance slurry is of great significance for the construction conditions of tunneling in strata with insufficient airtightness and low muck workability such as fissure water rock formations, water-rich sand layers, and pebble layers. Therefore, it is very necessary to develop a tunneling method using balance slurry to solve shield machine gushing. Summary of the Invention

[0003] The purpose of the present invention is to provide a tunneling method using balance slurry to solve shield machine gushing, which can not only improve the "workability" and "airtightness" of the surrounding strata, be conducive to establishing a stable air pressure in the soil chamber, but also improve the muck in the soil chamber and in front of the cutter head, be conducive to the smooth and continuous slag discharge of the screw conveyor, and at the same time improve the airtightness ability of the strata required for air pressure assistance, thereby solving the gushing problem.

[0004] In order to achieve the above purpose, the present invention adopts the following scheme:

[0005] A tunneling method using balance slurry to solve shield machine gushing, which comprises the following steps:

[0006] S1, mixing balance slurry;

[0007] S2, when "gushing" occurs during the tunneling of the shield machine, the shield machine stops tunneling, and the prepared balance slurry is injected outside the shield machine body through the advanced grouting holes provided on the side of the shield body close to the soil chamber and the radial holes arranged along the circumferential direction of the shield body to block the gaps and channels of water and gas gushing until the "gushing" situation is slowed down;

[0008] S3, using the 1 - 2 hours of the gap for assembling segments during shutdown, injecting balance slurry into the soil chamber and in front of the cutter head to fill the soil chamber and in front of the cutter head with balance slurry, and at the same time replacing and discharging the muck in the soil chamber and in front of the cutter head through the screw conveyor;

[0009] S4: After the slag replacement is completed and the pressure is stabilized, the automatic grouting system is used to continuously inject small amounts of shield mud into the soil bin for multiple pressurization. The pressure is increased by 0.2 bar per pressure level. Within 1 to 2 hours, the pressure in the soil bin is increased by two levels, that is, by 0.4 bar. This allows the shield mud to quickly block the water inflow channel in front of the shield body and reduce the amount of water inflow. In addition, during the pressurization process, a small amount of shield mud can be added to ensure that the bin is full.

[0010] S5. After the water and gas gushing gaps in the stratum surrounding the shield machine are sealed, the pressure in the soil bin is reduced and the air-slurry is replaced;

[0011] S6. Use the automatic pressure-maintaining system to inject air into the silo to maintain the silo pressure, start rotating the cutter head in place, and evenly discharge the slag through the spiral excavator. While discharging the slag, adjust the amount of air injected and ensure that the silo pressure is stable. Stop discharging the slag when the liquid level in the silo drops to 1 / 3 of the silo height.

[0012] S7. After the pressure in the bin stabilizes, configure the excavation parameters according to the height of the soil bin slag level, and continue excavation with the assistance of air pressure. If the "gushing" situation occurs again, enter the next cycle.

[0013] As a preferred embodiment of the present invention, in step S1, Hengdun mud is prepared from material A and material B, wherein clay slurry is used as material A and plasticizer is used as material B, and material A and material B are mixed to obtain Hengdun mud; wherein,

[0014] Material A is made by mixing clay dry powder and tap water in a weight ratio of 1:3 to 1:4, and mixing material A until the viscosity reaches 150dPa.s to 200dPa.s;

[0015] Material B is made by mixing plasticizer and tap water in a weight ratio of 1:1;

[0016] Material A and material B are mixed in a weight ratio of 15:1 to 25:1 before injection to obtain Hengdun mud. Stir thoroughly during mixing and ensure that the mixture is uniform. At the end of stirring, the viscosity is tested to reach 300dPa.s to 400dPa.s.

[0017] Furthermore, for deeply buried rock formations with developed fissure water, Hengdun Mud adopts a mixing scheme in which material A is mixed with clay dry powder and tap water in a weight ratio of 1:4, the weight ratio of material A to material B is 21:1, and the volume infiltration ratio is 1:25; among which, the volume incorporation ratio refers to the ratio of Hengdun Mud and slag soil mixed in proportion by volume.

[0018] Furthermore, for water-rich sand and gravel strata, Hengdun Mud adopts material A which is a mixture of clay dry powder and tap water in a weight ratio of 1:3, the weight ratio of material A to material B is 18:1, and the volume infiltration ratio is 1:20; among which, the volume infiltration ratio refers to the ratio of Hengdun Mud and slag soil mixed in proportion by volume.

[0019] As a preferred embodiment of the present invention, in step S2, the injection order of the shield mud is the bottom of the shield machine body - the symmetrical waist - the top, so that the shield mud wraps the body and strives to fill and split into the stratum cracks, construction excavation gaps, and water and gas gushing channels in the soft strata until it can no longer be injected.

[0020] As a preferred solution of the present invention, in step S3, there are three ways to inject shield mud into the soil bin and in front of the cutterhead:

[0021] The first injection method: when the machine is stopped to assemble the pipe, the shield mud is quickly pumped into the soil bin through the injection hole on the upper part of the shield bin partition;

[0022] The second injection method: use the shield machine's spiral excavator to reverse and pressurize, and inject shield mud into the lower part of the soil bin.

[0023] The third injection method: the first method and the second method are performed simultaneously.

[0024] As a preferred embodiment of the present invention, in step S3, during the injection of shield mud into the soil bin and in front of the cutterhead, the pressure above the soil bin is controlled within the range of 1.0 to 1.25 times the full bin shutdown pressure.

[0025] As a preferred embodiment of the present invention, in step S4, the graded pressurization adopts a secondary pressurization method:

[0026] First pressurization: After the slag soil replacement is completed, a synchronous grouting system is used to continuously inject a small amount of shield mud into the soil bin to ensure that the upper pressure of the soil bin increases by 0.2 bar on the basis of the full bin shutdown pressure. After reaching the target pressure, stop injecting the shield mud and observe the upper pressure of the soil bin. If the upper pressure of the soil bin decreases, continue to inject a small amount of shield mud until it stabilizes.

[0027] Second pressurization: Use the synchronous grouting system to inject a small amount of shield mud material into the soil bin. The control range of the upper pressure of the soil bin is the control range of the first pressurization plus an additional 0.2 bar. After the soil bin pressure reaches the target value, stop injecting the shield mud and observe the pressure on the upper part of the soil bin. If the soil bin pressure decreases, continue to inject a small amount of shield mud material until it stabilizes.

[0028] As a preferred embodiment of the present invention, in step S5, the process of pressure reduction and slurry replacement in the soil bin is as follows: Turn on the automatic pressure maintenance system. First, perform natural pressure reduction. After the natural pressure reduction stops, then perform pressure reduction by deflating to the pressure when the shield machine stops. When the air supply volume meets the specification requirements and the air pressure is stable, use the screw conveyor to discharge the Hengdun mud in the soil bin, and promptly supplement it with air pressure to lower the liquid level of the Hengdun mud. The liquid level height is higher than the slag inlet of the screw conveyor to prevent sudden deflation of the screw conveyor. After pressure reduction and slurry replacement, test the pressure maintenance effect. If the pressure maintenance requirements are not met, repeat the step of stepwise pressure increase.

[0029] As a preferred embodiment of the present invention, in step 6, during the slag discharging process, maintain the slag discharging balance by adjusting the rotation speed of the screw conveyor, and reasonably control the opening degree of the rear gate of the screw conveyor and the fluctuation of the soil bin pressure.

[0030] Implementing the tunneling method using Hengdun mud to solve the shield machine gushing problem provided by the present invention, compared with the prior art, its beneficial effects are as follows:

[0031] The tunneling method using Hengdun mud of the present invention is applicable to water-rich and airtightness-insufficient strata. By using Hengdun mud to penetrate and reinforce the strata around the shield machine, it can improve the "workability" and "airtightness" of the surrounding strata, reduce surrounding water and gas inflows, lower the probability of shield machine gushing, and is conducive to establishing a stable air pressure in the soil bin; in this state, the shield machine can use the air pressure assisted tunneling mode for tunneling; at the same time, Hengdun mud can also improve the muck in the soil bin and in front of the cutter head, which is beneficial for the smooth and continuous slag discharging of the screw conveyor; through the combination of Hengdun mud pressure maintenance and air pressure assistance, it improves the airtightness ability of the strata required for air pressure assistance, and thus solves the gushing problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of injecting Hengdun mud outside the shield machine body through the advanced grouting holes and radial holes provided on the shield body in the embodiment of the present invention;

[0033] Figure 2 It is a schematic diagram of injecting Hengdun mud into the soil bin in the embodiment of the present invention;

[0034] Figure 3 It is a schematic diagram of injecting Hengdun mud into the soil bin and in front of the cutter head in the embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of pressure reduction and slurry replacement in the soil bin in the embodiment of the present invention;

[0036] Figure 5 It is a schematic diagram of the shield machine continuing to tunnel under air pressure assistance after the pressure in the bin is stable in the embodiment of the present invention;

[0037] Figure 6 This is a schematic structural diagram of arranging injection holes on the bulkhead of the soil chamber in the embodiment of the present invention.

[0038] Reference numerals:

[0039] Hengdun mud 1; shield machine 2; advanced grouting hole 3; radial hole 4; soil chamber 5; cutter head 6; muck 7; injection hole 8; bulkhead of soil chamber 9; screw conveyor 10; segment 11. Specific embodiments

[0040] The following will further describe in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0041] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0042] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is more than two, and understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0043] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0044] As Figures 1 to 6 shown, a method for tunneling with Hengdun mud provided by the embodiment of the present invention to solve the problem of shield machine gushing includes the following steps:

[0045] S1, mixing of Hengdun mud 1;

[0046] In the step S1, the Hengdun mud 1 is prepared from a two-component material. The clay slurry is used as the A material, and the plasticizer is used as the B material. The A material and the B material are mixed and reacted to obtain the Hengdun mud 1; a professional shear pump device for Hengdun mud is used for mixing. Generally, the A material is composed of clay dry powder and tap water mixed at a weight ratio of 1:3 to 1:4, and the A material is mixed until the viscosity reaches 150 dPa·s to 200 dPa·s; the B material is composed of a plasticizer and tap water mixed at a weight ratio of 1:1; the A material and the B material are mixed at a weight ratio of 15:1 to 25:1 before injection to obtain the Hengdun mud 1. During mixing, it is fully stirred to ensure uniform mixing; when the mixing is completed, after testing, when its viscosity reaches 300 dPa·s to 400 dPa·s, it can meet the usage requirements under general conditions at the construction site.

[0047] For the deeply buried rock stratum with developed fissure water, the Hengdun mud 1 adopts a mixing ratio plan where the A material is composed of clay dry powder and tap water mixed at a weight ratio of 1:4, the mixing weight ratio of the A material and the B material is 21:1, and the volume infiltration ratio is 1:25. The laboratory slump test shows that the average slump of the improved muck is 18 cm, and the permeability test results show that the permeability coefficient is 5.5×10^~5 cm / s, meeting the requirements of the shield construction for the workability and impermeability of the muck.

[0048] For the water-rich sand layer and cobblestone layer stratum, the Hengdun mud 1 adopts a mixing ratio plan where the A material is composed of clay dry powder and tap water mixed at a weight ratio of 1:3, the mixing weight ratio of the A material and the B material is 18:1, and the volume infiltration ratio is 1:20. The laboratory test results show that the average slump of the improved muck is 17 cm, and the permeability coefficient is 4.8×10^~5 cm / s, which can effectively improve the workability and impermeability of the muck.

[0049] It should be noted that the volume incorporation ratio refers to the ratio of the Hengdun mud to the muck soil mixed according to the volume ratio. For example, the volume incorporation ratio mentioned above is 1:25, which means that every unit volume of the Hengdun mud is mixed with 25 unit volumes of the muck soil for improvement. This proportional relationship affects the properties of the improved muck, such as slump and permeability coefficient, etc. The volume of the muck soil is based on the amount of soil excavated per ring of the shield machine.

[0050] S2. When the "gushing" situation occurs during the tunneling of the shield machine 2, the shield machine 2 stops tunneling, and the prepared Hengdun mud 1 is injected outside the shield machine body through the advanced grouting holes 3 provided on the side of the shield body close to the soil bin and the radial holes 4 arranged along the circumferential direction of the shield body to block the gaps and channels of the gushing water and gas until the "gushing" situation is alleviated.

[0051] In step S2, if the "gushing" situation is more serious during the shield tunneling process and the water content of the stratum is relatively high, the shield mud 1 is injected from the advance grouting holes 3 and radial holes 4 of the shield machine 2 to block the gaps of the shield body where water and gas are gushing. Special attention is paid to the injection of the shield mud into the advance grouting holes 3 and radial holes 4 on the upper part of the shield machine 2; by controlling the injection amount and injection pressure of the shield mud, it is ensured that the shield mud injection fully fills the external space of the pipe segment 11 and the joints in the stratum (see Figure 1 The order of shield mud injection is from the bottom of the shield machine body to the symmetrical waist and then to the top, so that the shield mud wraps around the machine body and strives to fill and split into the stratum fissures, construction excavation gaps, and water and gas gushing channels in the soft strata until it can no longer be injected.

[0052] S3, using the 1 to 2 hours of downtime for assembling the segments 11, inject shield mud into the soil bin 5 and in front of the cutter head 6, so that the soil bin 5 and the front of the cutter head 6 are filled with shield mud (see Figure 2 and Figure 3 ), while the slag 7 in the soil bin 5 and in front of the cutter head 6 is replaced and discharged by the spiral excavator 10;

[0053] In step S3, there are three ways to inject shield mud into the soil bin 5 and in front of the cutter head 6:

[0054] The first injection method: when the machine is shut down to assemble the pipe, the shield mud is quickly pumped into the soil bin 5 through the injection hole 8 on the upper part of the shield machine soil bin partition 9. The location of the injection hole 8 is mainly the observation hole on the upper part of the soil bin partition. Before grouting, it is necessary to confirm that the observation hole is through, and use a synchronous grouting pipeline to connect the injection pump of the synchronous grouting system or the bentonite injection equipment and the observation hole on the upper part of the soil bin partition. Among them, the setting method of the observation hole on the upper part of the soil bin partition is to set 3 between the 10 o'clock position and the 2 o'clock position of the soil bin partition 9 and connect them to the balancing valve, one is arranged at 10 o'clock, one is arranged at 12 o'clock and one is arranged at 2 o'clock (see Figure 6 During the injection process, the pressure on the upper part of the soil bin 5 is controlled within the range of 1.0 to 1.25 times the full bin shutdown pressure.

[0055] The second injection method is to use the shield machine's spiral excavator 10 to reverse and pressurize, and inject shield mud into the lower part of the soil bin 5. During the injection process, the pressure in the upper part of the soil bin 5 is controlled within the range of 1.0 to 1.25 times the full bin shutdown pressure.

[0056] The third injection method: The first injection method and the second injection method are carried out simultaneously to quickly fill the soil bin 5 and the front of the cutter head 6 with the shield mud.

[0057] It should be noted that during rapid pumping, the soil pressure in the bin must be kept dynamically stable to prevent ground heave. The pressure-maintaining system is not activated during the entire injection process. However, to ensure that the pressure in the soil bin 5 does not fluctuate excessively, if necessary, the second injection method is not used simultaneously. Instead, the auger 10 is opened to discharge some of the soil 7 and reduce the pressure in the soil bin 5.

[0058] S4: After the replacement of the slag 7 is completed and the pressure is stabilized, the automatic grouting system is used to continuously inject small amounts of shield mud into the soil bin 5 multiple times to perform graded pressurization. With 0.2 bar as a pressure level, within 1 to 2 hours, the pressure in the soil bin 5 is increased by two levels, that is, by 0.4 bar. This allows the shield mud to quickly block the water inflow channel in front of the shield body and reduce the amount of water inflow. In addition, during the pressurization process, a small amount of shield mud can be added to ensure that the bin is full.

[0059] In step S4, the graded pressurization adopts a secondary pressurization method:

[0060] First pressurization: After the replacement of the slag 7 is completed, a small amount of shield mud is continuously injected into the soil bin 5 using the synchronous grouting system to ensure that the upper pressure of the soil bin is increased by 0.2 bar on the basis of the full bin shutdown pressure. After reaching the target pressure, stop injecting the shield mud and observe the upper pressure of the soil bin. If the upper pressure of the soil bin decreases, continue to inject a small amount of shield mud until it stabilizes.

[0061] Second pressurization: Use the synchronous grouting system to inject a small amount of shield mud material into the soil bin 5. The control range of the pressure on the upper part of the soil bin is the control range of the first pressurization plus an additional 0.2 bar. After the soil bin pressure reaches the target value, stop injecting the shield mud and observe the pressure on the upper part of the soil bin. If the soil bin pressure decreases, continue to inject a small amount of shield mud material until it stabilizes.

[0062] S5, after the water and gas gushing gaps in the stratum surrounding the shield machine 2 are blocked, the pressure in the soil bin 5 is reduced and the air-slurry is replaced;

[0063] In step S5, the automatic pressure maintaining system is turned on, and the pressure is first reduced naturally. After the natural pressure reduction stops, the pressure is reduced to the pressure when the shield machine 2 is shut down by deflation. When the air supply volume meets the specification requirements and the air pressure is stable, the spiral excavator 10 is used to discharge the shield mud in the soil bin 5 to lower the shield mud liquid level. The liquid level should be higher than the slag inlet of the spiral excavator 10 to prevent the spiral excavator 10 from sudden deflation (see Figure 4 ).

[0064] It should be noted that while the auger 10 is used to uniformly discharge the shield mud from the soil bin 5, it is necessary to promptly replenish it with air pressure. During the air-slurry replacement process, the shield mud level is gradually lowered, and changes in the soil bin pressure are closely observed. After pressure reduction and air-slurry replacement, the pressure maintenance effect is tested. If the pressure maintenance requirements are not met, the staged pressurization step is repeated.

[0065] S6. Inject air into the chamber using the automatic pressure - maintaining system to maintain the chamber pressure. Start rotating the cutter head 6 in place, and discharge slag evenly through the screw conveyor 10. While discharging slag, adjust the air injection volume and ensure the stability of the chamber pressure. After the liquid level in the chamber drops to 1 / 3 of the chamber height, stop discharging slag;

[0066] During the slag discharge process in step 6, the balance of slag discharge is mainly maintained by adjusting the rotation speed of the screw conveyor 10, and the opening of the rear gate of the screw conveyor 10 and the fluctuation of the soil chamber pressure are reasonably controlled. During the slag discharge process, as a large amount of muck 7 is carried out, the torque of the cutter head 6 gradually decreases, and the muck interface can be judged by the difference between the earth pressure gauges at the upper and lower parts of the cutter head 6.

[0067] S7. After the chamber pressure is stable, configure the tunneling parameters according to the muck level height in the soil chamber 5, and continue tunneling with the assistance of air pressure. When encountering the "gushing" situation again, enter the next cycle.

[0068] In step S7, the tunneling parameters mainly match the cutter head thrust, cutter head torque, cutter head rotation speed, the temperature of the cutter head and muck, the dry - wet degree of the muck, and the air pressure in the soil chamber; when starting tunneling, in the case of improving the tunneling speed and avoiding gushing, the shield machine tunnels in the mode where the propulsion is the easiest and the equipment load is the smallest.

[0069] It should be noted that the reduction of the muck level in the soil chamber reduces the frictional resistance between the back of the cutter head 6 and the soil chamber 5, effectively reducing the shield tunneling thrust and torque. Therefore, the tunneling speed can be increased by increasing the rotation speed of the cutter head 6 to accelerate the cutting of the soil. The stable air pressure in the soil chamber and the sealing of the Hengdun mud prevent external water inflow and stabilize the face, enabling the foam and Hengdun mud to be fully combined with the soil after injection, reducing the temperature of the muck and the cutter head 6, increasing the humidity and workability of the muck, ensuring smooth slag discharge, preventing mud cake formation, reducing the gushing risk, and having high construction efficiency.

[0070] In summary, implementing the tunneling method using Hengdun mud to solve shield machine gushing provided by the embodiments of the present invention is applicable to water - rich and air - tightness - insufficient strata. By using Hengdun mud to penetrate and reinforce the strata around the shield machine, it can improve the "workability" and "air - tightness" of the surrounding strata, reduce the surrounding water and gas inflow, reduce the shield machine gushing probability, and is conducive to establishing a stable air pressure in the soil chamber; in this state, the shield machine can use the air - pressure - assisted tunneling mode for tunneling; at the same time, Hengdun mud can also improve the muck in the soil chamber and in front of the cutter head, which is conducive to the smooth and continuous slag discharge of the screw conveyor; through the combination of Hengdun mud pressure - maintaining and air - pressure assistance, the air - tightness ability of the strata required for air - pressure assistance is improved, thereby solving the gushing problem.

[0071] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0072] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A tunneling method using balance shield mud to solve the problem of shield machine gushing, characterized in that, The following steps are involved: S1, Hengdun mud mixing; S2: When a "gushing" situation occurs during the shield machine's excavation, the shield machine stops excavating and uses the advance grouting holes on the side of the shield body close to the soil bin and the radial holes arranged along the circumference of the shield body to pressurize the mixed shield mud to the outside of the shield machine body to block the gaps and channels for water and gas gushing until the "gushing" situation is alleviated; S3: During the 1-2 hours between segments assembly, shield mud is injected into the soil bin and in front of the cutterhead, filling the soil bin and the cutterhead with shield mud. At the same time, the auger is used to displace and discharge the debris in the soil bin and in front of the cutterhead. S4: After the slag replacement is completed and the pressure is stabilized, the automatic grouting system is used to continuously inject small amounts of shield mud into the soil bin for multiple pressurization. The pressure is increased by 0.2 bar per pressure level. Within 1 to 2 hours, the pressure in the soil bin is increased by two levels, that is, by 0.4 bar. This allows the shield mud to quickly block the water inflow channel in front of the shield body and reduce the amount of water inflow. In addition, during the pressurization process, a small amount of shield mud can be added to ensure that the bin is full. S5. After the water and gas gushing gaps in the stratum surrounding the shield machine are sealed, the pressure in the soil bin is reduced and the air-slurry is replaced; S6. Use the automatic pressure-maintaining system to inject air into the silo to maintain the silo pressure, start rotating the cutter head in place, and evenly discharge the slag through the spiral excavator. While discharging the slag, adjust the amount of air injected and ensure that the silo pressure is stable. Stop discharging the slag when the liquid level in the silo drops to 1 / 3 of the silo height. S7. After the pressure in the bin stabilizes, configure the excavation parameters according to the height of the soil bin slag level, and continue excavation with the assistance of air pressure. If the "gushing" situation occurs again, enter the next cycle.

2. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 1, characterized in that, In step S1, Hengdun mud is prepared from material A and material B, wherein clay slurry is used as material A and plasticizer is used as material B, and material A and material B are mixed and reacted to obtain Hengdun mud; wherein, Material A is made by mixing clay dry powder and tap water in a weight ratio of 1:3 to 1:4, and mixing material A until the viscosity reaches 150dPa.s to 200dPa.s; Material B is made by mixing plasticizer and tap water in a weight ratio of 1:1; Material A and material B are mixed in a weight ratio of 15:1 to 25:1 before injection to obtain Hengdun mud. Stir thoroughly during mixing and ensure that the mixture is uniform. At the end of stirring, the viscosity is tested to reach 300dPa.s to 400dPa.s.

3. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 2, characterized in that, For deeply buried rock formations with developed fissured water, Hengdun Mud adopts material A which is a mixture of clay dry powder and tap water in a weight ratio of 1:4, the weight ratio of material A to material B is 21:1, and the volume infiltration ratio is 1:25; among which, the volume infiltration ratio refers to the ratio of Hengdun Mud and slag soil mixed in proportion by volume.

4. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 2, characterized in that For water-rich sand and gravel strata, Hengdun Mud adopts material A which is a mixture of clay dry powder and tap water in a weight ratio of 1:3, the weight ratio of material A to material B is 18:1, and the volume infiltration ratio is 1:20; among which, the volume infiltration ratio refers to the ratio of Hengdun Mud and slag soil mixed in proportion by volume.

5. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 1, characterized in that, In step S2, the injection order of the shield mud is the bottom of the shield machine body - the symmetrical waist - the top, so that the shield mud wraps the body and strives to fill and split into the stratum cracks, construction excavation gaps, and water and gas gushing channels in the soft strata until it can no longer be injected.

6. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 1, characterized in that, In step S3, there are three ways to inject shield mud into the soil bin and in front of the cutterhead: The first injection method: when the machine is stopped to assemble the pipe, the shield mud is quickly pumped into the soil bin through the injection hole on the upper part of the shield bin partition; The second injection method: use the shield machine's spiral excavator to reverse and pressurize, and inject shield mud into the lower part of the soil bin. The third injection method: the first method and the second method are performed simultaneously.

7. A tunneling method using Hengdun mud for solving the gushing problem of a shield machine, characterized in that, In step S3, during the process of injecting shield mud into the soil bin and in front of the cutterhead, the pressure above the soil bin is controlled within the range of 1.0 to 1.25 times the full bin shutdown pressure.

8. A tunneling method using Hengdun mud for solving the gushing problem of a shield machine according to claim 1, characterized in that In step S4, the graded pressurization adopts a secondary pressurization method: First pressurization: After the slag soil replacement is completed, a synchronous grouting system is used to continuously inject a small amount of shield mud into the soil bin to ensure that the upper pressure of the soil bin increases by 0.2 bar on the basis of the full bin shutdown pressure. After reaching the target pressure, stop injecting the shield mud and observe the upper pressure of the soil bin. If the upper pressure of the soil bin decreases, continue to inject a small amount of shield mud until it stabilizes. Second pressurization: Use the synchronous grouting system to inject a small amount of shield mud material into the soil bin. The control range of the upper pressure of the soil bin is the control range of the first pressurization plus an additional 0.2 bar. After the soil bin pressure reaches the target value, stop injecting the shield mud and observe the pressure on the upper part of the soil bin. If the soil bin pressure decreases, continue to inject a small amount of shield mud material until it stabilizes.

9. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 1, characterized in that, In step S5, the process of reducing the pressure in the soil bin and replacing the air-slurry is as follows: start the automatic pressure maintaining system, first use natural pressure reduction, and after the natural pressure reduction stops, use air release to reduce the pressure to the pressure when the shield machine is shut down; when the air supply volume meets the specification requirements and the air pressure is stable, use the spiral excavator to discharge the shield mud in the soil bin, and replenish it with air pressure in time to lower the shield mud liquid level. The liquid level height is higher than the slag inlet of the spiral excavator to prevent sudden air release of the spiral excavator; after the pressure reduction and air-slurry replacement, test the pressure maintaining effect. If the pressure maintaining requirements are not met, re-perform the graded pressurization step.

10. A tunneling method using Hengdun mud for solving shield machine gushing according to claim 1, characterized in that, In step 6, during the slag discharge process, the slag discharge balance is maintained by adjusting the number of revolutions of the spiral excavator, and the fluctuation of the gate opening behind the spiral excavator and the soil bin pressure is reasonably controlled.

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