Water-rich soft stratum shield step-by-step combined grouting system and using method thereof

Abstract

The invention relates to the technical field of water-rich soft stratum shield tunneling control, and discloses a water-rich soft stratum shield step-by-step combined grouting system which comprises an anterior shield horizontal advance grouting reinforcement module, a middle shield inclined advance grouting module, a middle shield radial mud-effect-preventing injection module and a shield tail synchronous grouting module on a shield tail. The stratum in front of the shield tunneling machine is subjected to continuous advanced grouting reinforcement along with excavation, the surrounding stratum in front of the shield tunneling machine is subjected to continuous advanced grouting reinforcement along with excavation, and a gullet is injected into the surrounding stratum of the shield tunneling machine to fill a gap between the shield tunneling machine and a tunnel wall and a gap between a grouting filling duct piece and the tunnel wall. The invention further discloses a using method of the water-rich soft stratum shield step-by-step combined grouting system. According to the water-rich soft stratum shield step-by-step combined grouting system and the using method thereof, stratum deformation induced in all stages of shield tunneling can be reduced, and grouting reinforcement in the whole shield tunneling process of the water-rich soft stratum and precise prevention and control over building and structure cracking are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel excavation control in water-rich soft strata, and in particular to a shield step-by-step combined grouting system in water-rich soft strata and a use method thereof. Background Art

[0002] my country is one of the countries with the largest scale, fastest development and highest construction difficulty of tunnel construction in the world. A large number of urban rail transit tunnels are being built or will be built soon. The shield method has become one of the main methods for building urban rail transit tunnels due to its advantages of "fast excavation speed, high tunnel quality, small construction disturbance, high economic and social benefits, safe and environmentally friendly construction".

[0003] At present, conventional strata shield tunneling control technology has been relatively mature. However, water-rich soft strata have the characteristics of high compressibility, low cohesion, poor self-stability, large porosity, and strong permeability. The shield tunneling process is very likely to cause strata disturbance and excessive deformation. If reasonable methods are not used in time for grouting reinforcement control, it will induce safety risks such as tilting of high-rise buildings and cracking of municipal roads.

[0004] For example, the Nanjing Metro Line 7 caused the high-rise building to tilt more than 0.75% due to the unreasonable shield grouting method in the water-rich sand layer. Another example is that the Nanchang Metro shield tunnel underpass road in the water-rich sand layer caused a subsidence of about 15cm deep and 3m2 in area on the municipal road surface due to improper grouting control. In order to solve the problem of excessive deformation of the stratum induced by tunnel excavation in water-rich soft strata, a shield step-by-step joint grouting reinforcement system and method is needed to help ensure the safe and efficient excavation of urban rail transit tunnels. The results of the literature survey show that the current research on shield grouting methods is mostly focused on the optimization design of synchronous grouting and secondary grouting materials and devices.

[0005] A Chinese patent (publication date: August 1, 2023, publication number: CN116517560A) discloses a high-pressure assisted excavation construction method for a large-diameter shield tunnel in water-rich strata, and a Chinese patent (publication date: August 15, 2023, publication number: CN116591702A) discloses a shield construction method for passing through existing buildings. Both are aimed at shield tunneling under buildings in water-rich soft strata, and propose a stratum reinforcement method using "synchronous grouting + secondary grouting". However, it can only prevent excessive stratum deformation during the shield tail disengagement stage and after the shield passes, and cannot control the stratum deformation induced before the shield passes and during the shield body passes.

[0006] A Chinese patent (publication date: June 23, 2023, publication number: CN116291575A) discloses a grouting reinforcement construction process for a shield tunnel close to a structure. The grouting reinforcement construction process for a shield tunnel close to a structure arranges grouting holes along the front and rear ends of the centerline of the shield tunnel and on both sides of the structure to pre-reinforce the building. However, this method, by pre-drilling holes around the building for grouting, has the disadvantages of causing great disturbance to the surrounding strata and buildings, being unable to perform advance grouting reinforcement during excavation, and being difficult to adjust the grouting parameters according to the excavation progress.

[0007] In summary, the current research on shield grouting reinforcement technology in water-rich soft strata focuses on the optimization of grouting materials and equipment. There are few research results on grouting technology, and the stratum deformation induced by "before the shield passes - the shield body passes - the shield tail escapes - after the shield passes" is not fully considered. It is difficult to achieve accurate prevention and control of stratum grouting reinforcement and building cracking during the entire shield excavation process. Summary of the invention

[0008] The purpose of the present invention is to address the deficiencies of the above-mentioned technology and to provide a step-by-step joint grouting system for shield tunneling in water-rich soft strata and a method of using the system, which can reduce the stratum deformation induced by each stage of the shield tunneling, and achieve grouting reinforcement and precise prevention and control of cracking of buildings and structures throughout the entire process of shield tunneling in water-rich soft strata.

[0009] To achieve the above-mentioned purpose, the shield step-by-step joint grouting system for water-rich soft strata designed in the present invention comprises a front shield horizontal advance grouting reinforcement module on the front shield of the shield machine, a middle shield inclined advance grouting module on the middle shield, a middle shield radial mud-reducing effect injection module on the middle shield and a shield tail synchronous grouting module on the shield tail, which are sequentially arranged; the front shield horizontal advance grouting reinforcement module performs continuous advance grouting reinforcement on the stratum directly in front of the shield machine as it is excavated, the middle shield inclined advance grouting module performs continuous advance grouting reinforcement on the stratum around the front of the shield machine as it is excavated, the middle shield radial mud-reducing effect injection module injects mud-reducing effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall, and the shield tail synchronous grouting module fills the gap between the pipe segment and the tunnel wall by grouting.

[0010] Preferably, the front shield horizontal advance grouting reinforcement module includes a plurality of horizontal advance grouting holes arranged on the main drive outer side of the front shield partition and a horizontal advance grouting rod for providing slurry to the horizontal advance grouting holes, and the middle shield inclined advance grouting module on the middle shield includes a plurality of inclined advance grouting holes arranged on the outer wall of the middle shield and an inclined advance grouting rod for providing slurry to the inclined advance grouting holes.

[0011] Preferably, the angle formed by the inclined advance grouting rod and the horizontal axis of the shield machine is 8 to 10 degrees.

[0012] Preferably, the inclined advance grouting holes form several circles on the outer wall of the middle shield, and the inclined advance grouting holes in the same circle are non-equidistantly distributed, the hole spacing gradually decreases from top to bottom, and the hole distribution gradually becomes denser, which is conducive to the slurry to densely fill the excavation gap from bottom to top under the action of gravity.

[0013] Preferably, the Zhongdun radial mud effect injection module includes a Zhongdun radial grouting hole arranged on the outer wall of the Zhongdun, and a mixing nozzle is provided on the Zhongdun radial grouting hole. The Zhongdun radial grouting hole is connected to a water glass solution box through a water glass solution injection pipe, and is connected to a stirring box through a mud effect solution injection pipe. The stirring box is provided with a water inlet and a hopper for adding mud effect powder.

[0014] Preferably, the mass ratio of water to gram-slurry powder added to the mixing box is 1:(1.5-2), the flow rate ratio of the gram-slurry solution injection pipe and the water glass solution injection pipe is 1:(15-20), the viscosity value of the gram-slurry is not less than 600 dPas, and the permeability coefficient K is greater than 4.2×10 -10 cm / s, the effective mud injection volume is 150% to 200% of the volume of the gap between the middle shield and the cave wall, and the effective mud injection pressure is 30 to 50 kPa higher than the water and soil pressure at the injection position.

[0015] Preferably, the shield tail synchronous grouting module includes a synchronous grouting pipe located between the pipe segment and the cave wall for injecting double liquid slurry, a shield tail brush is provided between the synchronous grouting pipe and the pipe segment, and a slurry stop plate is provided between the synchronous grouting pipe and the cave wall.

[0016] Preferably, it also includes a segment secondary grouting module installed in the shield tail, the segment is provided with an openable and closable secondary grouting hole, and the segment secondary grouting module fills the pores after the synchronous grouting of the shield tail synchronous grouting module through the secondary grouting hole.

[0017] A method for using a shield step-by-step combined grouting system for water-rich soft strata comprises the following steps:

[0018] A) Before the shield machine passes through the water-rich soft strata, the front shield horizontal advance grouting reinforcement module is used to carry out continuous advance grouting reinforcement on the strata directly in front of the shield, and the middle shield inclined advance grouting module is used to carry out continuous advance grouting reinforcement on the strata around the shield in front of the shield to prevent excessive deformation of the surrounding strata before the shield passes;

[0019] B) When the shield machine passes through the water-rich soft strata, the radial mud effect injection module of the shield is used to inject mud effect into the strata around the shield machine to fill the gap between the shield machine and the tunnel wall, so as to prevent excessive deformation of the surrounding strata during the shield passing stage, and form a low-permeability sealing layer around the shield machine to block groundwater leakage;

[0020] C) When the shield machine is out of the water-rich soft stratum, the shield tail synchronous grouting module is used to fill the gap between the segment and the tunnel wall with grouting to prevent excessive deformation of the surrounding stratum during the shield tail outgoing stage.

[0021] Preferably, it also includes a segment secondary grouting module installed in the shield tail, and the segment is provided with openable and closable secondary grouting holes. After the shield machine passes through the water-rich soft stratum, the density of the synchronous grouting is detected. For the local hollow parts behind the segment, the segment secondary grouting module is used to perform secondary grouting and filling through the secondary grouting holes. The termination condition is that the cement mortar cannot be injected or slurry flows out of the adjacent secondary grouting holes.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. By adopting "advance grouting - injection of mud effect - synchronous grouting - secondary grouting", the ground deformation induced by "before the shield passes - shield body passes - shield tail escapes - after the shield passes" can be reduced respectively, and grouting reinforcement and precise prevention and control of cracking of buildings and structures in the whole process of shield tunneling in water-rich soft strata can be achieved;

[0024] 2. The inclined advance holes are distributed non-equidistantly around the middle shield. The hole spacing decreases from the top to the bottom, and the hole distribution gradually becomes denser, which is conducive to the slurry filling the excavation gap densely from the bottom to the top under the action of gravity;

[0025] 3. The mud-effective material can fill the gap between the shield machine and the tunnel wall in time to prevent excessive deformation of the surrounding strata due to the gap between the shield body and the tunnel wall during the shield passing stage. At the same time, it has the characteristics of high viscosity and low permeability, and can form a low-permeability sealing barrier layer around the shield body, effectively preventing leakage accidents during shield tunneling in water-rich soft strata. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the step-by-step combined grouting system of the shield in water-rich soft stratum of the present invention;

[0027] Figure 2 for Figure 1 Structural schematic diagram of the horizontal advance grouting reinforcement module of the middle front shield;

[0028] Figure 3 for Figure 2 Right view of;

[0029] Figure 4 for Figure 1 Structural diagram of the Zhongzhongdun inclined advance grouting module;

[0030] Figure 5 for Figure 4 Schematic diagram of the cross section at AA in the middle;

[0031] Figure 6 for Figure 1 Schematic diagram of the structure of the radial mud injection module of Zhongzhongdun;

[0032] Figure 7 for Figure 1 Structural diagram of synchronous grouting module at the middle shield tail;

[0033] Figure 8 It is a schematic diagram of the structure of the pipe segment in the present invention.

[0034] The components in the figure are numbered as follows:

[0035] Front shield 1, front shield horizontal advance grouting reinforcement module 2, middle shield 3, middle shield inclined advance grouting module 4, middle shield radial mud-killing effect injection module 5, shield tail 6, shield tail synchronous grouting module 7, cave wall 8, pipe segment 9, front shield partition 10, horizontal advance grouting hole 11, horizontal advance grouting rod 12, inclined advance grouting hole 13, inclined advance grouting rod 14, middle shield radial grouting hole 15, water glass solution injection pipe 16, water glass solution box 17, mud-killing effect solution injection pipe 18, mixing box 19, water inlet 20, hopper 21, synchronous grouting pipe 22, shield tail brush 23, slurry stop plate 24, secondary grouting hole 25, main drive 26, flow meter 27 pressure gauge 28 first inclined advance grouting rod 29, second inclined advance grouting rod 30, third inclined advance grouting rod 31, double liquid slurry 32. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] like Figures 1 to 8 As shown, a step-by-step joint grouting system for shield tunneling in water-rich soft strata comprises a front shield horizontal advance grouting reinforcement module 2, a middle shield inclined advance grouting module 4, a middle shield radial mud-reducing effect injection module 5 and a shield tail synchronous grouting module 7 on a shield tail 6, which are sequentially arranged on a front shield 1 of a shield machine; the front shield horizontal advance grouting reinforcement module 2 performs continuous advance grouting reinforcement on the stratum directly in front of the shield machine as it is excavated, the middle shield inclined advance grouting module 4 performs continuous advance grouting reinforcement on the stratum around the front of the shield machine as it is excavated, the middle shield radial mud-reducing effect injection module 5 injects mud-reducing effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall 8, and the shield tail synchronous grouting module 7 fills the gap between the pipe segment 9 and the tunnel wall 8 by grouting.

[0039] When this embodiment is used, the following steps are included:

[0040] A) Before the shield machine passes through the water-rich soft stratum, the front shield horizontal advance grouting reinforcement module 2 is used to perform continuous advance grouting reinforcement on the stratum directly in front of the shield, and the middle shield inclined advance grouting module 4 is used to perform continuous advance grouting reinforcement on the stratum around the front of the shield to prevent excessive deformation of the surrounding stratum before the shield passes;

[0041] B) When the shield machine passes through a water-rich soft stratum, the shield radial mud effect injection module 5 injects mud effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall 8, thereby preventing excessive deformation of the surrounding stratum during the shield passing stage, and forming a low-permeability sealing layer around the shield machine to block groundwater leakage;

[0042] C) When the shield machine is out of the water-rich soft stratum, the shield tail synchronous grouting module 7 is used to fill the gap between the pipe segment 9 and the tunnel wall 8 with grouting to prevent excessive deformation of the surrounding stratum during the shield tail 6 out of the stage.

[0043] Example 2

[0044] like Figures 1 to 8 As shown, a step-by-step joint grouting system for shield tunneling in water-rich soft strata comprises a front shield horizontal advance grouting reinforcement module 2, a middle shield inclined advance grouting module 4, a middle shield radial mud-reducing effect injection module 5 and a shield tail synchronous grouting module 7 on a shield tail 6, which are sequentially arranged on a front shield 1 of a shield machine; the front shield horizontal advance grouting reinforcement module 2 performs continuous advance grouting reinforcement on the stratum directly in front of the shield machine as it is excavated, the middle shield inclined advance grouting module 4 performs continuous advance grouting reinforcement on the stratum around the front of the shield machine as it is excavated, the middle shield radial mud-reducing effect injection module 5 injects mud-reducing effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall 8, and the shield tail synchronous grouting module 7 fills the gap between the pipe segment 9 and the tunnel wall 8 by grouting.

[0045] Among them, combined Figure 2 and Figure 3As shown, the front shield horizontal advance grouting reinforcement module 2 includes a plurality of horizontal advance grouting holes 11 arranged on the outer side of the main drive 26 on the front shield partition 10 and a horizontal advance grouting rod 12 for providing slurry for the horizontal advance grouting holes 11. The middle shield inclined advance grouting module 4 on the middle shield 3 includes a plurality of inclined advance grouting holes 13 arranged on the outer wall of the middle shield 3 and an inclined advance grouting rod 14 for providing slurry for the inclined advance grouting holes 13. Specifically, the inclined advance grouting rod 14 is shaped with the horizontal axis of the shield machine. The angle formed is 8 to 10 degrees. In this embodiment, there is a large overlap length between the inclined advance grouting hole 13 and the middle shield 3, which can accurately guide and control the inclined advance grouting rod 14 to an inclination angle of 8°. In addition, the inclined advance grouting holes 14 form 3 circles on the outer wall of the middle shield 3. The inclined advance grouting holes 14 in the same circle are not equidistantly distributed, and the hole spacing from top to bottom gradually decreases, and the hole position distribution gradually becomes dense, which is conducive to the slurry to densely fill the excavation gap from bottom to top under the action of gravity.

[0046] Specifically, Figure 4 and Figure 5 As shown, when the shield machine is at the initial position, the grouting hole formed by the first inclined advance grouting rod 29 on the AA section is located at the relatively outermost side, when the shield machine advances forward a distance Δl, the grouting hole formed by the second inclined advance grouting rod 30 on the AA section is located at a relatively middle position, and when the shield machine continues to advance forward a distance Δl, the grouting hole formed by the third inclined advance grouting rod 31 on the AA section is located at the relatively innermost side. As the shield machine continues to advance forward, a reinforcement area with a radius of R = r + (LM) × tanα will gradually be formed on the AA section, where r is the outer diameter of the shield, L is the horizontal projection length of the inclined advance grouting rod 14, M is the horizontal projection length of the inclined advance grouting rod 14 located inside the shield machine, and α is the inclined advance grouting rod 14.

[0047] In addition, if Figure 6 As shown, the Zhongdun radial mud effect injection module 5 includes a Zhongdun radial grouting hole 15 arranged on the outer wall of the Zhongdun 3, and a mixing nozzle is provided on the Zhongdun radial grouting hole 15. The Zhongdun radial grouting hole 15 is connected to a water glass solution tank 17 through a water glass solution injection pipe 16, and is connected to a stirring box 19 through a mud effect solution injection pipe 18. The stirring box 19 is provided with a water inlet 20 and a hopper 21 for adding mud effect powder.

[0048] Again, if Figure 7As shown, the shield tail synchronous grouting module 7 includes a synchronous grouting pipe 22 located between the pipe segment 9 and the cave wall 8 for injecting double liquid slurry, a shield tail brush 23 is provided between the synchronous grouting pipe 22 and the pipe segment 9, and a slurry stop plate 24 is provided between the synchronous grouting pipe 22 and the cave wall 8. The double liquid slurry 32 is injected into the gap between the cave wall 8 and the pipe segment 9 through the synchronous grouting pipe 22 located inside the shield tail 6 to prevent excessive deformation of the cave wall 8 during the shield tail escape stage. The slurry stop plate 24 can prevent the double liquid slurry 32 from jumping into the gap between the cave wall 8 and the shield tail 6.

[0049] When this embodiment is used, the following steps are included:

[0050] A) Before the shield machine passes through the water-rich soft stratum, the front shield horizontal advance grouting reinforcement module 2 is used to perform continuous advance grouting reinforcement on the stratum directly in front of the shield, and the middle shield inclined advance grouting module 4 is used to perform continuous advance grouting reinforcement on the stratum around the front of the shield to prevent excessive deformation of the surrounding stratum before the shield passes;

[0051] B) When the shield machine passes through a water-rich soft stratum, the shield radial mud effect injection module 5 injects mud effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall 8, thereby preventing excessive deformation of the surrounding stratum during the shield passing stage, and forming a low-permeability sealing layer around the shield machine to block groundwater leakage;

[0052] C) When the shield machine is out of the water-rich soft stratum, the shield tail synchronous grouting module 7 is used to fill the gap between the pipe segment 9 and the tunnel wall 8 with grouting to prevent excessive deformation of the surrounding stratum during the shield tail 6 out of the stage.

[0053] Example 3

[0054] like Figure 1 As shown, a step-by-step joint grouting system for shield tunneling in water-rich soft strata comprises a front shield horizontal advance grouting reinforcement module 2, a middle shield inclined advance grouting module 4, a middle shield radial mud-reducing effect injection module 5 and a shield tail synchronous grouting module 7 on a shield tail 6, which are sequentially arranged on a front shield 1 of a shield machine; the front shield horizontal advance grouting reinforcement module 2 performs continuous advance grouting reinforcement on the stratum directly in front of the shield machine as it is excavated, the middle shield inclined advance grouting module 4 performs continuous advance grouting reinforcement on the stratum around the front of the shield machine as it is excavated, the middle shield radial mud-reducing effect injection module 5 injects mud-reducing effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall 8, and the shield tail synchronous grouting module 7 fills the gap between the pipe segment 9 and the tunnel wall 8 by grouting.

[0055] Among them, the front shield horizontal advance grouting reinforcement module 2 includes a plurality of horizontal advance grouting holes 11 arranged on the outside of the main drive 26 on the front shield partition 10 and a horizontal advance grouting rod 12 for providing slurry for the horizontal advance grouting holes 11. The middle shield inclined advance grouting module 4 on the middle shield 3 includes a plurality of inclined advance grouting holes 13 arranged on the outer wall of the middle shield 3 and an inclined advance grouting rod 14 for providing slurry for the inclined advance grouting holes 13. Specifically, the angle formed by the inclined advance grouting rod 14 and the horizontal axis of the shield machine is 8 to 10 degrees, which is 8 degrees in this embodiment. In addition, the inclined advance grouting holes 14 form a plurality of circles on the outer wall of the middle shield 3. The inclined advance grouting holes 14 in the same circle are not equidistantly distributed, and the hole spacing from top to bottom gradually decreases, and the hole position distribution gradually becomes dense, which is conducive to the slurry filling the excavation gap densely from bottom to top under the action of gravity.

[0056] In addition, the middle shield radial mud effect injection module 5 includes a middle shield radial grouting hole 15 arranged on the outer wall of the middle shield 3, and a mixing nozzle is arranged on the middle shield radial grouting hole 15. The middle shield radial grouting hole 15 is connected to a water glass solution box 17 through a water glass solution injection pipe 16, and is connected to a stirring box 19 through a mud effect solution injection pipe 18. The stirring box 19 is provided with a water inlet 20 and a hopper 21 for adding mud effect powder. The mud effect solution is formed by uniformly mixing water and mud effect powder. The water glass and the mud effect solution are respectively transported by the water glass solution injection pipe 16 and the mud effect solution injection pipe 18, and are sprayed out from the mixing nozzle in the middle shield radial grouting hole 15 to form a mud effect, so as to fill the gap between the shield machine and the tunnel wall 8 in time.

[0057] Specifically, the mass ratio of water and gram-slime powder added to the mixing box 19 is 1:(1.5-2), which is 1:1.75 in this embodiment. The flow ratio of the gram-slime solution injection pipe 18 and the water glass solution injection pipe 16 is 1:(15-20), which is 1:19 in this embodiment. The viscosity of the gram-slime is not less than 600 dPas, and the permeability coefficient K is greater than 4.2×10 -10 In this embodiment, a flow meter 27 and a pressure gauge 24 are provided on the water glass solution injection pipe 16 and the gramineous solution injection pipe 18 to facilitate monitoring of the mixing of the water glass solution and the gramineous solution.

[0058] Again, the shield tail synchronous grouting module 7 includes a synchronous grouting pipe 22 located between the pipe segment 9 and the cave wall 8 for injecting double liquid slurry, a shield tail brush 23 is provided between the synchronous grouting pipe 22 and the pipe segment 9, and a slurry stop plate 24 is provided between the synchronous grouting pipe 22 and the cave wall 8. The double liquid slurry 32 is injected into the gap between the cave wall 8 and the pipe segment 9 through the synchronous grouting pipe 22 located inside the shield tail 6 to prevent excessive deformation of the cave wall 8 during the shield tail escape stage. The slurry stop plate 24 can prevent the double liquid slurry 32 from jumping into the gap between the cave wall 8 and the shield tail 6.

[0059] When this embodiment is used, the following steps are included:

[0060] A) Before the shield machine passes through the water-rich soft stratum, the front shield horizontal advance grouting reinforcement module 2 is used to perform continuous advance grouting reinforcement on the stratum directly in front of the shield, and the middle shield inclined advance grouting module 4 is used to perform continuous advance grouting reinforcement on the stratum around the front of the shield to prevent excessive deformation of the surrounding stratum before the shield passes. The front shield horizontal advance grouting parameters and the middle shield inclined advance grouting parameters can be adjusted in real time according to the changes in the stratum. In this embodiment, the reinforcement distance L of each cycle is 20 meters;

[0061] B) When the shield machine passes through a water-rich soft stratum, the shield radial mud effect injection module 5 is used to inject mud effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall 8, so as to prevent excessive deformation of the surrounding stratum during the shield passing stage, and form a low-permeability sealing layer around the shield machine to block groundwater leakage. The mud effect injection volume is 150% to 200% of the volume of the gap between the middle shield 3 and the tunnel wall 8, and the mud effect injection pressure is 30 to 50 kPa higher than the water and soil pressure at the injection position;

[0062] C) When the shield machine exits the water-rich soft stratum, the shield tail synchronous grouting module 7 is used to fill the gap between the segment 9 and the tunnel wall 8 with grouting to prevent excessive deformation of the surrounding stratum during the shield tail 6 exit stage. The grouting volume is controlled to be 130% to 200% of the gap between the segment 9 and the tunnel wall 8, and the grouting pressure is 30 to 50 kPa higher than the water and soil pressure.

[0063] Finally, in the above embodiment, a secondary grouting module for the segment installed in the shield tail 6 can also be provided. Figure 8 As shown, the segment 9 is provided with an openable and closable secondary grouting hole 25. The segment secondary grouting module uses the secondary grouting hole 25 to fill the pores after the synchronous grouting of the shield tail synchronous grouting module 7. Specifically, during construction, after the shield machine passes through the water-rich soft stratum, the density of the synchronous grouting is detected. For the local hollow parts behind the segment 9, the segment secondary grouting module is used to perform secondary grouting and filling through the secondary grouting holes 25. The flow rate and pressure of the secondary grouting of the segment 9 can be automatically recorded by the sensor, and the termination condition is that the cement mortar cannot be injected or the slurry flows out of the adjacent secondary grouting holes 25, so as to prevent the surrounding strata from excessive consolidation and deformation after the shield passes.

[0064] The step-by-step combined grouting system for shield tunneling in water-rich and soft strata of the present invention and the use method thereof can respectively reduce the stratum deformation induced by "before the shield tunneling passes - the shield body passes - the shield tail escapes - after the shield tunneling passes" by adopting "advance grouting - injection of mud-reducing effect - synchronous grouting - secondary grouting", so as to realize the grouting reinforcement and precise prevention and control of cracking of buildings and structures in the whole process of shield tunneling in water-rich and soft strata; the inclined advance holes are non-equidistantly distributed around the middle shield 3, the hole spacing from top to bottom is reduced, and the hole position distribution is gradually dense, which is conducive to the slurry to densely fill the excavation gap from bottom to top under the action of gravity; the mud-reducing effect material can fill the gap between the shield machine and the tunnel wall 8 in time, and prevent the surrounding strata from excessive deformation due to the gap between the shield body and the tunnel wall 8 during the shield tunneling stage; at the same time, it has the characteristics of high viscosity and low permeability, and can form a low-permeability sealing barrier layer around the shield body, effectively preventing leakage accidents during the shield tunneling in water-rich and soft strata.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A step-by-step combined grouting system for shield tunneling in water-rich soft strata, characterized in that: The invention comprises a front shield horizontal advance grouting reinforcement module (2) on a front shield (1) of a shield machine, a middle shield inclined advance grouting module (4) on a middle shield (3), a middle shield radial mud-reducing effect injection module (5) on the middle shield (3), and a shield tail synchronous grouting module (7) on a shield tail (6) which are sequentially arranged; the front shield horizontal advance grouting reinforcement module (2) performs continuous advance grouting reinforcement on the stratum directly in front of the shield machine as it is excavated, the middle shield inclined advance grouting module (4) performs continuous advance grouting reinforcement on the stratum around the front of the shield machine as it is excavated, the middle shield radial mud-reducing effect injection module (5) injects mud-reducing effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall (8), and the shield tail synchronous grouting module (7) performs grouting to fill the gap between the pipe segment (9) and the tunnel wall (8).

2. According to claim 1, the shield step-by-step joint grouting system for water-rich soft strata is characterized by: The front shield horizontal advance grouting reinforcement module (2) comprises a plurality of horizontal advance grouting holes (11) arranged on the outside of the main drive (26) on the front shield partition (10) and a horizontal advance grouting rod (12) for providing slurry to the horizontal advance grouting holes (11), and the middle shield inclined advance grouting module (4) on the middle shield (3) comprises a plurality of inclined advance grouting holes (13) arranged on the outer wall of the middle shield (3) and an inclined advance grouting rod (14) for providing slurry to the inclined advance grouting holes (13).

3. The shield step-by-step joint grouting system for water-rich soft strata according to claim 2 is characterized by: The angle formed by the inclined advanced grouting rod (14) and the horizontal axis of the shield machine is 8 to 10 degrees.

4. The shield step-by-step joint grouting system for water-rich soft strata according to claim 2 is characterized by: The inclined advanced grouting holes (14) form a plurality of circles on the outer wall of the middle shield (3). The inclined advanced grouting holes (14) in the same circle are non-equidistantly distributed, the hole spacing gradually decreases from the top to the bottom, and the hole position distribution gradually becomes denser.

5. The shield step-by-step joint grouting system for water-rich soft strata according to claim 1 is characterized by: The central shield radial mud-reducing effect injection module (5) comprises a central shield radial grouting hole (15) provided on the outer wall of the central shield (3), a mixing nozzle being provided on the central shield radial grouting hole (15), the central shield radial grouting hole (15) being connected to a water glass solution tank (17) via a water glass solution injection pipe (16), and being connected to a stirring tank (19) via a mud-reducing effect solution injection pipe (18), the stirring tank (19) being provided with a water inlet (20) and a hopper (21) for adding mud-reducing effect powder.

6. The shield step-by-step joint grouting system for water-rich soft strata according to claim 5 is characterized by: The mass ratio of water and gramineous powder added to the stirring box (19) is 1:(1.5-2), the flow rate ratio of the gramineous solution injection pipe (18) and the water glass solution injection pipe (16) is 1:(15-20), the viscosity value of the gramineous powder is not less than 600 dPas, and the permeability coefficient K is greater than 4.2×10 -10 cm / s, the effective mud injection volume is 150% to 200% of the volume of the gap between the middle shield (3) and the cave wall (8), and the effective mud injection pressure is 30 to 50 kPa higher than the water and soil pressure at the injection position.

7. The shield step-by-step combined grouting system for water-rich soft strata according to claim 1 is characterized by: The shield tail synchronous grouting module (7) comprises a synchronous grouting pipe (22) located between the pipe segment (9) and the cave wall (8) for injecting double liquid slurry, a shield tail brush (23) is provided between the synchronous grouting pipe (22) and the pipe segment (9), and a slurry stop plate (24) is provided between the synchronous grouting pipe (22) and the cave wall (8).

8. The shield step-by-step joint grouting system for water-rich soft strata according to claim 1 is characterized by: It also comprises a segment secondary grouting module installed in the shield tail (6), the segment (9) being provided with an openable and closable secondary grouting hole (25), and the segment secondary grouting module is used to fill grouting holes in the pores after synchronous grouting by the synchronous grouting module (7) of the shield tail through the secondary grouting hole (25).

9. A method for using the shield step-by-step combined grouting system for water-rich soft strata according to any one of claims 1 to 7, characterized in that: The steps include: A) Before the shield machine passes through the water-rich soft stratum, the front shield horizontal advance grouting reinforcement module (2) is used to perform continuous advance grouting reinforcement on the stratum directly in front of the shield machine, and the middle shield inclined advance grouting module (4) is used to perform continuous advance grouting reinforcement on the stratum around the front of the shield machine; B) When the shield machine passes through a water-rich soft stratum, the shield radial mud effect injection module (5) is used to inject mud effect into the stratum around the shield machine to fill the gap between the shield machine and the tunnel wall (8); C) When the shield machine exits the water-rich soft stratum, the shield tail synchronous grouting module (7) is used to inject grout to fill the gap between the pipe segment (9) and the tunnel wall (8).

10. The method for using the shield step-by-step combined grouting system for water-rich soft strata according to claim 9 is characterized by: It also includes a segment secondary grouting module installed in the shield tail (6), wherein the segment (9) is provided with an openable and closable secondary grouting hole (25). After the shield machine passes through a water-rich soft stratum, the compactness of the synchronous grouting is detected. For the local hollow parts behind the segment (9), the segment secondary grouting module is used to perform secondary grouting and filling through the secondary grouting holes (25), and the termination condition is that cement mortar cannot be injected or slurry flows out of adjacent secondary grouting holes (25).

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