Active control device and grouting method for disturbance during shield construction in sandy and gravel strata

Abstract

The present invention discloses an active control device for disturbance during shield construction in sand and gravel strata and a grouting method, and relates to the technical field of grouting for shield construction. It comprises a head pipe, a joint pipe, a sleeve valve pipe and a bladder bag. There are several sleeve valve pipes, and every two sleeve valve pipes are screwed and fixed. The joint pipe and the head pipe are screwed to the sleeve valve pipe, and at least one joint pipe is provided. The grouting device is inserted into the sleeve valve pipe and slides in the sleeve valve pipe. The two ends of the bladder bag are respectively fixed at the positions of the joint pipe and the head pipe. The bladder bag and the head pipe are fixed with a throat clamp. The present invention solves the problem of connecting the existing sleeve valve pipe and the bladder bag through the grouting device and its use method, and realizes the staged and regional control of the disturbance deformation of the stratum during tunnel shield construction. The technology of the present invention can directly purchase sleeve valve pipes of existing specifications without the need for a separate mold, and is easy to promote and apply. The sleeve valve pipe and the bladder bag are reliably connected, and the tightening force can be increased to avoid the connection from being detached during construction.

Description

Technical Field

[0001] The invention relates to the technical field of shield construction grouting, in particular to a sand and gravel stratum shield construction disturbance active control device and a grouting method. Background Art

[0002] Shield tunneling inevitably disturbs the surrounding soil, and soil loss during construction can cause surface settlement and stress changes in the surrounding soil. To control surface settlement and soil disturbance, compensatory grouting is used as a post-construction remedial measure to compensate for soil loss caused by tunnel excavation, stabilize the tunnel, and raise the ground surface. Water-rich gravel strata are common in underground engineering construction. Characterized by a loose structure, high permeability, and a large porosity, they are typically mechanically unstable. Grouting materials in these strata are easily diluted by water, leading to significant loss and lack of restraint, resulting in poor grouting effectiveness. Bladders can limit the grouting range, but unlike soft soils, achieving a compressive effect in gravel strata generally requires higher grouting pressures. Connecting the bladder to the grouting device is a key issue. Furthermore, the location and timing of grouting also present challenges in controlling ground deformation. Currently, there is a need to develop a device that can deliver multiple grouting injections at specific locations, enabling a method for zoned grouting during shield tunneling.

[0003] Regarding the combined use of bladder bags and grouting, (CN105672940A) discloses a grouting water stopper with a membrane bag positioned outside the grouting hole; (CN116220736A) discloses a membrane bag sleeve valve tube secondary grouting device and construction process for dynamic water sealing in karst tunnels; (CN108411920A) discloses a multi-point bladder grouting device and method for controlling soil deformation; and (CN113638398A) discloses a method for active dynamic control of soil stress in bladder grouting. The above disclosed technologies involve the application principles of bladder bags and sleeve valve tubes, but do not address the issue of how to reliably connect the bladder bag and sleeve valve tube, or simply tie them with wire. However, when the bladder diameter reaches 250mm and the grouting pressure reaches 2MPa, the core issue becomes a reliable connection between the bladder bag and sleeve valve tube. The existing sleeve valve tube has a diameter of 48mm. The diameter difference between the bag and the sleeve valve tube is large, so it cannot be tied tightly, causing leakage; the sleeve valve tube is made of PVC material, with small bearing capacity, and cannot withstand large binding force; the sleeve valve tube joint is a threaded connection. When the bag length reaches 20m, it will be lowered vertically, which will cause the joint to fall off.

[0004] Bladder grouting technology can be used to control ground deformation. (CN116641391B) discloses a double-row bladder grouting method for controlling deformation in foundation pits adjacent to tunnels. Multiple rows of bladders of varying depths are used to grout the pit at different stages of excavation, controlling deformation. Reserved bladders for secondary grouting allow for multiple grouting cycles. However, this technical solution is costly and impractical for sites with limited space. Furthermore, the document does not provide a specific connection scheme between the bladders and the grouting device, but rather describes application scenarios for bladder grouting.

[0005] The existing technical solutions do not provide the connection between the bladder bag and the grouting device and the position and time of grouting during shield construction, so they cannot solve the bladder grouting problem of controlling the disturbance of sand and gravel strata caused by shield construction. Summary of the Invention

[0006] The purpose of the present invention is to provide an active control device for disturbance during shield construction in sandy and gravel strata and a grouting method to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an active control device for disturbance in shield construction in sand and gravel strata, comprising: a head pipe, a joint pipe, a sleeve valve pipe and a bladder bag; a plurality of sleeve valve pipes are provided, and every two sleeve valve pipes are screwed and fixed, the joint pipe and the head pipe are screwed to the sleeve valve pipe, and at least one joint pipe is provided, the grouting device is inserted into the sleeve valve pipe and slides in the sleeve valve pipe, the two ends of the bladder bag are respectively fixed at the positions of the joint pipe and the head pipe, the bladder bag is fixed to the head pipe with a throat clamp 1, and the bladder bag is fixed to the joint pipe with a throat clamp 2.

[0008] Furthermore, the head pipe is provided with at least three grooves for positioning the first throat clamp, and the joint pipe is also provided with at least three grooves for positioning the second throat clamp.

[0009] Furthermore, one end of the sleeve valve tube is provided with an external thread 1, and the other end of the sleeve valve tube is provided with a thickened threaded joint that can be screwed and fixed with the external thread 1.

[0010] Furthermore, two tightening nuts 1 and 2 are screwed together at both ends of the grouting device, wherein a gap is provided between the tightening nuts 1, and a rubber plug is provided in the gap and is sleeved on the surface of the grouting device. The tightening nuts 2 are fixed with a rubber head, and the rubber head is conical in shape, with the narrower end facing one end of the head tube. At least two slurry outlets are provided on the grouting device, and the slurry outlets are located between the rubber head and the rubber plug.

[0011] Furthermore, one end of the head pipe connected to the sleeve valve pipe is provided with an internal thread 2, which is connected to an external thread 1 of the sleeve valve pipe. The two ends of the joint pipe are respectively provided with an external thread 2 and an internal thread 1, which is screwed to the thickened part of the threaded joint of the sleeve valve pipe, and the internal thread 1 is screwed to one external thread of the sleeve valve pipe.

[0012] The invention discloses a grouting method for an active control device for disturbance during shield construction in sandy and gravel strata, which adopts the above-mentioned active control device for disturbance during shield construction in sandy and gravel strata, and comprises the following steps: step 1: determining the drilling arrangement and drilling, and determining the main control area A and the secondary control area B; step 2: making a bladder grouting device; step 3: lowering the bladder grouting device; and step 4: grouting construction. During shield construction, synchronous grouting is carried out after the shield tail of the shield machine is separated from the pipe segment. The grouting effect of the water-rich pebble layer is poor, and grouting of the main control area A is carried out at this time.

[0013] Furthermore, in the step 1, determining the drilling arrangement requires delineating the shield construction control sensitive area, setting the soil volume loss rate, performing finite element simulation on the tunnel construction, and determining the depth of the main control area A and the secondary control area B above the tunnel within the tunnel depth range based on the deformation; in the step 1, the bottom elevation of the main control area A should be at least 1.0m below the tunnel bottom, and the top elevation of the main control area A should be at least 1.0m above the tunnel top.

[0014] Furthermore, the drilling depth in step one needs to be determined according to the vertical position of the bag, and the over-drilling depth of the drilling is not less than the length of the head pipe. From the cross-sectional perspective of the sensitive area of shield construction, the drilling position is located on both sides of the tunnel.

[0015] Furthermore, during the production process of the bladder grouting device, it is necessary to determine the position of the joint pipe according to the depth of the main control area A and the secondary control area B delineated in step one. One joint pipe is located at the depth intersection of the main control area A and the secondary control area B, and another joint pipe is located at the top elevation of the secondary control area B.

[0016] Furthermore, the lowering of the bladder grouting device in step three includes the following steps: P: using a car crane to turn over and erect the bladder grouting device; P: moving the bladder grouting device to the drilling position and lowering it, and after the lowering is completed, backfilling the gaps in the hole with fine sand; P: after the bladder bag is lowered, it is stabilized for at least three days, during which time the gaps in the hole are backfilled with fine sand, and the gaps are filled until they can no longer be filled.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The bladder grouting device and method for controlling the disturbance of sand and gravel strata caused by shield construction solve the problem of the connection between the existing sleeve valve tube and the bladder bag through the grouting device and the use method thereof, and realize the stage-by-stage and regional control of the disturbance deformation of the stratum caused by tunnel shield construction. The technology of the present invention can directly purchase the sleeve valve tube of existing specifications without the need for a separate mold, and is easy to promote and apply. The sleeve valve tube and the bladder bag are reliably connected, and the tightening force can be increased to avoid the connection from being separated during the construction process. The stage-by-stage and regional control of the disturbance deformation of the stratum is realized, and a simple process can be used to achieve complex control. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the bladder grouting device of the present invention;

[0020] Figure 2 This is a schematic diagram of the disassembled structure of the bladder grouting device of the present invention;

[0021] Figure 3 It is a schematic diagram of grouting in shield construction of the present invention.

[0022] In the figure: 1. Bladder; 2. Sleeve valve tube; 201. External thread 1; 202. Thickened threaded joint; 3. Connector pipe; 301. External thread 2; 302. Internal thread 1; 4. Head pipe; 401. Internal thread 2; 5. Hose clamp 1; 6. Hose clamp 2; 7. Grouting device; 701. Slurry outlet; 702. Tightening nut 1; 703. Rubber plug; 704. Tightening nut 2; 705. Rubber head; 8. Stratified sedimentation instrument. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] like Figure 1 and Figure 2 As shown, the present invention provides a technical solution: an active control device for disturbance during shield construction in sand and gravel strata, comprising a head pipe 4, a joint pipe 3, a sleeve valve pipe 2 and a bag 1.

[0025] The sleeve valve tube 2 is provided with several sections, and every two sleeve valve tubes 2 are screwed and fixed, the joint tube 3 and the head tube 4 are screwed to the sleeve valve tube 2, and the joint tube 3 is provided with at least one, the grouting device 7 is inserted into the sleeve valve tube 2 and slides in the sleeve valve tube 2, the two ends of the bag 1 are respectively fixed at the positions of the joint tube 3 and the head tube 4, and are fixed to the head tube 4 with a throat clamp 5, and fixed to the joint tube 3 with a throat clamp 6, wherein the sleeve valve tube 2 is a grouting equipment, which consists of a tube body and a one-way sleeve valve to realize the one-way grouting function. In this embodiment, the sleeve valve in the sleeve valve tube 2 is arranged near the external thread 201. Since the sleeve valve is in the tube body, it is a prior art and is not shown in the figure.

[0026] In the above embodiment, the grouting device 7 can be moved to each sleeve valve pipe 2 to perform grouting.

[0027] like Figure 2As shown, in order to ensure the smooth implementation of the above embodiment, it is necessary to understand that at least three grooves are provided on the outer surface of the head tube 4 to facilitate the positioning of the throat clamp 5 and to facilitate the throat clamp 5 to tie and fix the bag 1. At least three grooves are also provided on the joint tube 3 to facilitate the positioning of the throat clamp 2 6 and to facilitate the throat clamp 2 6 to tie and fix the bag 1. That is to say, the two ends of the bag 1 are fixed to the head tube 4 and the joint tube 3 respectively by the throat clamp 1 5 and the throat clamp 2 6. In this case, the bag 1 is in a basically sealed state.

[0028] like Figure 2 As shown, in order to ensure the smooth implementation of the above embodiment, it is necessary to understand that one end of the sleeve valve tube 2 is provided with an external thread 201, and the other end is provided with a thickened threaded joint 202 that can be screwed and fixed with the external thread 201, that is, every two sleeve valve tubes 2 can be screwed and fixed.

[0029] like Figure 2 As shown, what needs to be understood about this solution is that two ends of the grouting device 7 are respectively screwed with two tightening nuts 1 702 and tightening nuts 2 704, wherein a gap is provided between the two tightening nuts 1 702, and a rubber plug 703 sleeved on the surface of the grouting device 7 is provided in the gap, and the tightening nut 2 704 is fixed with a rubber head 705, which is conical in shape, and the narrower end faces one end of the head tube 4, and a seal can be achieved between the rubber plug 703 and the rubber head 705. At least two slurry outlets 701 are provided on the grouting device 7, and the outlet The slurry outlet 701 is located between the rubber head 705 and the rubber plug 703, wherein the grouting device 7 is sealed at one end toward the head tube 4, and is connected to the grouting equipment at the other end away from the head tube 4. In this case, when the grouting device 7 performs grouting, the slurry only spreads between the rubber head 705 and the rubber plug 703, and the grouting device 7 is located in the sleeve valve tube 2. That is to say, when the slurry overflows from the grouting device 7, the slurry overflows in the sleeve valve tube 2, and in the sleeve valve tube 2, the area between the rubber head 705 and the rubber plug 703 is sealed.

[0030] like Figure 2 As shown, in order to ensure the smooth implementation of this embodiment, it is also necessary to know that one end of the head tube 4 connected to the sleeve valve tube 2 is provided with an internal thread 2 401, and the internal thread 2 401 is connected to the external thread 1 201 of the sleeve valve tube 2. The two ends of the joint tube 3 are respectively provided with an external thread 2 301 and an internal thread 1 302. The external thread 2 301 is screwed to the thickened thread joint 202 of the sleeve valve tube 2, and the internal thread 1 302 is screwed to the external thread 1 201 of the sleeve valve tube 2. Through this structure, the connection between the sleeve valve tube 2, the joint tube 3 and the head tube 4 can be realized.

[0031] In summary, the bladder grouting device can realize segmented grouting and adjustment of the grouting position. After the sleeve valve tube 2, the joint tube 3 and the head tube 4 are connected and fixed, the grouting device 7 can slide in the inner wall of the entire sleeve valve tube 2 and perform grouting at any time. After the grouting device 7 discharges the slurry, the slurry overflows from the grouting device 7 and spreads to the bladder bag 1 through the one-way overflow effect of the sleeve valve tube 2, thereby filling the bladder bag 1.

[0032] by Figure 3 As shown, based on the above-mentioned capsule grouting device, we propose a new grouting method for active control of disturbance of shield construction in sandy and gravel strata, which includes the following steps:

[0033] Step 1: Determine the drilling layout and drill the holes.

[0034] The shield construction control sensitive area is delineated, and then the soil volume loss rate is set. Finite element simulation of the tunnel construction is performed, and the depth of the main control area A within the tunnel depth range and the secondary control area B above the tunnel are determined according to the deformation.

[0035] Regarding step one, in the gravel stratum, due to its strong permeability, changes in groundwater levels will affect the stability of the stratum. Therefore, combined with hydrogeological data, with the tunnel as the center, sensitive areas are delineated along a certain range in the longitudinal and transverse directions of the tunnel. In the longitudinal direction, it starts from 3-5 meters in front of the tunnel face and extends backward to 6-10 meters behind the shield tail. In the transverse direction, it extends 1-3 meters on both sides from the outer contour of the tunnel as the sensitive area.

[0036] During drilling, a shield tunnel construction model is established using numerical simulation software (such as FLAC-3D or MIDAS-GTS). Various parameters of the sand and gravel strata, including particle size distribution, porosity, internal friction angle, and cohesion, are taken into account. By simulating the stratum deformation and structural stress conditions under different soil volume loss rates, the soil volume loss rates are set to different values such as 0.5%, 1%, 1.5%, and 2%, and the corresponding surface settlement values, tunnel convergence values, and the responses of surrounding buildings and pipelines are observed. Based on this, the depths of the main control area A within the tunnel depth range and the secondary control area B above the tunnel are planned and drilled.

[0037] Among them, the bottom elevation of the main control area A should be at least 1.0m below the bottom of the tunnel, and the top elevation of the main control area A should be at least 1.0m above the top of the tunnel.

[0038] In step one, the drilling depth needs to be determined according to the vertical position of the bag 1, and the over-drilling depth of the drilling must not be less than the length of the head pipe 4. The plane position of the drilling hole is set on both sides of the tunnel, and the drilling diameter is 150 mm. That is to say, from the cross-sectional perspective of the sensitive area of shield construction, the drilling position is located on both sides of the tunnel.

[0039] Step 2: Preparation of bladder grouting device.

[0040] F1: Determine the position of the joint pipe 3 according to the depth of the main control area A and the secondary control area B delineated in step 1. One joint pipe 3 is located at the depth boundary of the main control area A and the secondary control area B, and another joint pipe 3 is located at the top elevation of the secondary control area B. That is, the main control area A and the secondary control area B are separated into two independent filling areas A and B by the bladder grouting device, which control the deformation of the main control area A and the secondary control area B respectively.

[0041] F2: Connect the sleeve valve tube 2 and the joint tube 3, insert the bottom end of the connected sleeve valve tube 2 into the head tube 4, set three throat clamps 5 in the groove position of the head tube 4, tighten them, and set three throat clamps 6 in the groove of the joint tube 3, tighten them.

[0042] Step 3: Lower the bladder grouting device.

[0043] P1: Use a car crane to turn over and erect the bladder grouting device.

[0044] P2: Move the bladder grouting device to the drilling position and lower it. After lowering, fill the gaps in the hole with fine sand.

[0045] P3: It is recommended to stabilize the bag 1 for at least three days after it is lowered. During this period, fill the gaps in the hole with fine sand several times until the gaps can no longer be filled, ensuring that the bag 1 is in close contact with the surrounding soil without affecting the control effect.

[0046] Step 4: Grouting construction. During shield construction, synchronous grouting will be carried out after the shield tail of the shield machine separates from the pipe segment. The grouting effect of the water-rich pebble layer is poor, so grouting is carried out in the main control area A at this time.

[0047] G1: Insert the grouting device 7 into the sleeve valve tube 2 and perform grouting of the inner bag 1 at the depth of the main control area A.

[0048] G2: After grouting is completed, observe the monitoring data of the stratified settlement instrument 8. When soil settlement occurs above the tunnel, grouting is carried out in the secondary control area B.

[0049] After each grouting is completed, the sleeve valve pipe 2 is cleaned to facilitate subsequent grouting.

[0050] During the start-up of bladder grouting and for two days after the completion of grouting, the monitoring frequency should be maintained at once every two hours.

[0051] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is limited by the accompanying embodiments and their equivalents.

Claims

1. A grouting method for an active control device for disturbance during shield construction in sandy and gravel strata, characterized in that: include: A sealing pipe (4), a joint pipe (3), a sleeve valve pipe (2) and a bag (1); a plurality of sleeve valve pipes (2) are provided, and every two sleeve valve pipes (2) are screwed and fixed, the joint pipe (3) and the sealing pipe (4) are screwed to the sleeve valve pipe (2), and at least one joint pipe (3) is provided, a grouting device (7) is inserted into the sleeve valve pipe (2) and slides in the sleeve valve pipe (2), two ends of the bag (1) are respectively fixed to the joint pipe (3) and the sealing pipe (4), the bag (1) and the sealing pipe (4) are fixed by a throat clamp (5), and the bag (1) and the joint pipe (3) are fixed by a throat clamp (6); The grouting device (7) is provided with a rubber plug (703) and a rubber head (705) at both ends, respectively. The grouting device (7) is sealed at one end facing the head tube (4), and the end facing away from the head tube (4) is connected to the grouting equipment. After the sleeve valve tube (2), the joint tube (3) and the sealing tube (4) are connected and fixed, the grouting device (7) slides in the inner wall of the entire sleeve valve tube (2) and performs segmented grouting at any time. When the slurry overflows from the grouting device (7), the area between the rubber sealing head (705) and the rubber plug (703) in the sleeve valve tube (2) is sealed. After the slurry overflows from the grouting device (7), it overflows into the bag (1) through the sleeve valve tube (2). The sealing tube (4) is provided with at least three grooves for positioning the throat clamp (5), and the joint tube (3) is also provided with at least three grooves for positioning the throat clamp (6). One end of the sleeve valve tube (2) is provided with an external thread (201), and the other end of the sleeve valve tube (2) is provided with a threaded joint thickening (202) that can be screwed and fixed with the external thread (201); return The method includes the following steps: Step 1: Determine the drilling layout and drill holes to determine the main control area A and the secondary control area B; Step 2: Make a bladder grouting device; Step 3: Lower the bladder grouting device; Step 4: Grouting construction. During shield construction, synchronous grouting is carried out after the shield tail of the shield machine is separated from the segment. The grouting effect of the water-rich pebble layer is poor, so grouting is carried out in the main control area A at this time; During the manufacturing process of the bladder grouting device, the position of the joint pipe (3) needs to be determined according to the depth of the main control area A and the secondary control area B delineated in step 1. One joint pipe (3) is located at the depth boundary of the main control area A and the secondary control area B, and another joint pipe (3) is located at the top elevation of the secondary control area B.

2. The grouting method of the active control device for disturbance during shield construction in sandy and gravel strata according to claim 1, characterized in that: The two ends of the grouting device (7) are respectively screwed with two tightening nuts (702) and two tightening nuts (704), wherein a gap is provided between the tightening nuts (702), a rubber plug (703) is provided in the gap and sleeved on the surface of the grouting device (7), a rubber seal (705) is fixed on the tightening nut (704), the rubber seal (705) is conical, and the narrower end faces one end of the seal pipe (4), and at least two slurry outlets (701) are provided on the grouting device (7), and the slurry outlets (701) are located between the rubber seal (705) and the rubber plug (703).

3. The grouting method of the active control device for disturbance during shield construction in sandy and gravel strata according to claim 1 is characterized in that: One end of the sealing tube (4) connected to the sleeve valve tube (2) is provided with an internal thread 2 (401), and the internal thread 2 (401) is connected to the external thread 1 (201) of the sleeve valve tube (2). Both ends of the joint tube (3) are provided with an external thread 2 (301) and an internal thread 1 (302), respectively. The external thread 2 (301) is screwed to the thickened thread joint (202) of the sleeve valve tube (2), and the internal thread 1 (302) is screwed to the external thread 1 (201) of the sleeve valve tube (2).

4. The grouting method of the active control device for disturbance during shield construction in sandy and gravel strata according to claim 1 is characterized in that: Determining the drilling arrangement in step one requires delineating the shield construction control sensitive area, setting the soil volume loss rate, performing finite element simulation on the tunnel construction, and determining the depth of the main control area A and the secondary control area B above the tunnel within the tunnel depth range based on the deformation; in step one, the bottom elevation of the main control area A should be at least 1.0m below the tunnel bottom, and the top elevation of the main control area A should be at least 1.0m above the tunnel top.

5. The grouting method of the active disturbance control device for shield construction in sandy and gravel strata according to claim 1 is characterized in that: The drilling depth in step 1 needs to be determined according to the vertical position of the bag (1), and the over-drilling depth of the drilling is not less than the length of the head pipe (4). From the perspective of the cross section of the sensitive area of shield construction, the drilling position is located on both sides of the tunnel.

6. The grouting method of the active disturbance control device for shield construction in sandy and gravel strata according to claim 1, characterized in that: Lowering the bladder grouting device in step 3 comprises the following steps: P1: using a car crane to turn over and erect the bladder grouting device; P2: moving the bladder grouting device to the position of the drill hole (12) and lowering it, and after the lowering is completed, backfilling the gaps in the hole with fine sand; P3: after the bladder bag (1) is lowered, it is stabilized for at least three days, during which time the gaps in the hole are backfilled with fine sand, filling the gaps until the gaps cannot be filled further.

Images