An inflatable bag structure and construction method for displacement correction of operating subway tunnels

Abstract

The present invention discloses an inflatable bag structure and construction method for correcting the displacement of an operating subway tunnel, including an inflatable bag, a central tie rod and a telescopic frame arranged around the central tie rod are arranged inside the inflatable bag, a conical cap tip fixedly connected to the central tie rod is arranged on the top, and a sealing plug is connected to the bottom, and a hole is reserved in the center of the sealing plug for the central tie rod, an inflatable pipe and a soil delivery pipe to extend into, the inflatable pipe is supplied with air by an inflating device, and the soil delivery pipe is supplied with filling soil by the soil delivery device. The method of using an inflatable bag for inflating and extruding correction can minimize the impact on the surroundings to the greatest extent, avoiding the great impact on the surrounding environment in the traditional sleeve valve pipe grouting, which may cause unnecessary deformation of other adjacent pipelines or structures. It is suitable for local tunnel displacement correction in underground spaces with dense pipelines.

Description

Technical Field

[0001] The invention belongs to the technical field of reinforcement and protection of operating subway tunnels, and in particular relates to an inflatable bag structure and a construction method for displacement correction of operating subway tunnels. Background Art

[0002] With the development of urban underground space, more and more pipelines and structures have appeared in the limited shallow ground space. Since subway tunnels are sensitive to displacement, the construction of new tunnels, foundation pit excavation, large pile foundation, large-scale ground loading and other construction effects near existing operating subway tunnels may cause local displacement and deformation of existing tunnels in all directions, affecting the normal operation and structural safety of the tunnels.

[0003] In order to deal with excessive tunnel displacement, grouting correction is often used in engineering. Traditional grouting correction technology often uses sleeve valve pipes for compaction grouting. Specifically, vertical sleeve valve pipes can be arranged for grouting to correct the horizontal deviation of the tunnel, and oblique sleeve valve pipes can be arranged for vertical correction. However, in actual engineering, slurry is prone to slurrying in the soil, and the volume, position and direction of the injected slurry are difficult to accurately control, which can easily cause secondary effects on other surrounding structures. When there are both bodies to be corrected and non-corrected bodies in a small space, or when the correction amounts of multiple bodies to be corrected are different, the difficulty of traditional sleeve valve pipe correction schemes in sleeve valve pipe arrangement, grouting amount, and grouting pressure control will increase sharply, which is often difficult to achieve in reality. At the same time, the correction form of sleeve valve pipe grouting is not flexible enough, and the grouting process is irreversible. If too much slurry is injected, it is very easy to cause excessive correction, and reverse grouting is required in another direction, causing unnecessary waste, time and effort. In addition to the sleeve valve tube grouting correction technology, another common correction measure for operating tunnels in engineering is the grouting behind the pipe segment wall. The existing grouting behind the wall technology is mostly to directly perform high-pressure grouting to the outside of the pipe segment through the grouting hole, and use the splitting and penetration of the slurry to reinforce the surrounding soil layer. This method can correct the floating or sinking deformation of the tunnel in a short period of time, but because the ratio of cement blocks formed by the solidification of general slurry to soil is greater than that of the surrounding soft soil, in the later operation process, the cement blocks will accelerate the sinking of the tunnel, affecting the operation of the tunnel and the safety of the structure. In addition, whether it is the sleeve valve tube technology or the grouting behind the wall technology, it often requires the injection of a large amount of slurry, which will cause greater pollution to the soil and groundwater sources, which is not conducive to environmental protection.

[0004] In summary, the existing grouting correction technology for shield tunnels has the following main problems: the correction effect is difficult to accurately control, it has a great impact on other nearby non-correction objects, the correction form is inflexible, the construction plan design is complex, it pollutes the environment, and it is easy to accelerate settlement after construction. These problems urgently need to be solved by improving the technology. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an inflatable bag structure and a construction method for correcting displacement of an operating subway tunnel.

[0006] To achieve the above technical objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides an inflatable bag structure for correcting displacement of an operating subway tunnel, including an inflatable bag, wherein a central pull rod and a telescopic frame arranged around the central pull rod are arranged inside the inflatable bag, a conical cap tip fixedly connected to the central pull rod is arranged on the top, and a sealing plug is connected to the bottom, a hole is reserved in the center of the sealing plug for the central pull rod, an inflation pipe and a soil delivery pipe to extend into, the inflation pipe is supplied with air by an inflation device, and the soil delivery pipe is supplied with filling soil by the soil delivery device.

[0008] Furthermore, the inflation pipe is connected to a first speed limiting control valve and a first flow meter, and the soil delivery pipe is connected to a second speed limiting control valve and a second flow meter.

[0009] Furthermore, the inflation device adopts a first inflation pump.

[0010] Furthermore, the soil delivery device includes a second air pump and a soil collecting box, and the soil delivery pipe is connected to the second air pump and the soil collecting box respectively.

[0011] Furthermore, the telescopic frame is arranged at equal angles along the longitudinal direction of the inner surface of the airbag, and the telescopic frame and the airbag can be folded or opened synchronously.

[0012] Furthermore, the telescopic frame is made of steel material and is divided into a plurality of segments, the segments are connected by hinges, and the telescopic frame can be divided into a folded state and an extended state.

[0013] Furthermore, when used for grouting holes in the upper half section of a tunnel, the front end of the air filling pipe and the front end of the soil delivery pipe are 5-8 cm away from the tip of the conical cap, and the front end of the air filling pipe is at the top, and the front end of the soil delivery pipe is at the bottom, staggered from top to bottom;

[0014] When used for grouting holes in the lower half of the tunnel section, the front ports of the inflation tube and the soil delivery tube are inserted into the inflation bag 5-8 cm away from the sealing plug, and the front port of the inflation tube is on top and the front port of the soil delivery tube is on the bottom, staggered from top to bottom.

[0015] Furthermore, a three-layer anti-backsucking device is arranged at the front end of the inflation tube, and the three-layer anti-backsucking device is composed of a wire mesh, a filter cloth and a wire mesh from top to bottom.

[0016] Furthermore, the inflatable bags are arranged in the tunnel displacement section according to the principle of dense in the middle and sparse at both ends. Two inflatable bags are arranged on the same ring tunnel segment, and the two inflatable bags are arranged on the left and right sides of the tunnel segment respectively. The angle between the position of the left inflatable bag and the vertical direction is α, and the inflation volume is V α , the angle between the right airbag and the vertical direction is β, and the inflation volume is V β , the inflation volume and angle meet The specific inflation volume is determined according to the tunnel's deviation correction displacement.

[0017] In a second aspect, an embodiment of the present invention further provides a construction method for a displacement correction inflatable bag structure for an operating subway tunnel, comprising the following steps:

[0018] 1) Measurement and layout design: Measure the length and deformation of the tunnel deformation section, mark the available grouting holes within the section, measure the angles α and β between the grouting holes on the left and right sides of the same ring of the tunnel and the vertical direction, and determine the number, spacing and range of the inflatable bags through calculation and analysis;

[0019] 2) Production of the inflatable bag: Put an anti-backflow device on the end of the inflatable pipe, insert the inflatable pipe and the soil delivery pipe through the small hole on the sealing plug and into the inflatable bag. Select the appropriate insertion depth according to the use position of the inflatable bag. After assembly, apply waterproof coating on the internal channel and side of the sealing plug;

[0020] 3) Insertion of the inflatable bag: Push the folded inflatable bag into the grouting hole. When it is inserted into the specified depth of the soft soil layer behind the wall, insert and fix the sealing plug into the grouting hole, apply slurry to the inner surface of the sealing plug for waterproofing, and repeat the above operation until all the inflatable bags are driven into the specified grouting holes;

[0021] 4) Inflation correction process: With the real-time tunnel monitoring technology, open the inflation device and the first speed control valve, close the second speed control valve, and start to inflate using the corresponding inflation tube on each inflatable bag. During the inflation process, make full use of the first speed control valve and the first flow meter, and pay strict attention to the inflation volume and inflation speed of each inflatable bag. The inflation volume of the two circumferential inflatable bags should be adjusted according to the The inflation process is carried out synchronously. First, the inflatable bag near the center of the deformation zone is inflated and corrected along the longitudinal direction of the tunnel, and then it is gradually inflated symmetrically on both sides. During the inflation process of each inflatable bag, the internal telescopic frame is gradually opened;

[0022] 5) Tunnel deformation recovery: After the tunnel deviation correction is completed, first close the first speed limit control valve and inflation device of each inflatable bag, stabilize for a period of time, and wait for the tunnel longitudinal deformation to recover;

[0023] 6) Soil replacement process: After the longitudinal deformation of the tunnel is restored, the soil delivery device is first turned on to suck the filling soil into the soil delivery pipe through high-pressure gas. Then, the second speed limit control valve and the first speed limit control valve are slowly opened synchronously. The indications of the second flow meter and the first flow meter are closely observed. The volume of gas delivered by the soil delivery pipe is strictly controlled to be equal to the volume of gas discharged by the inflation pipe to maintain the size of the inflation bag unchanged. As the gas replacement process proceeds, the filling soil inside the inflation bag will gradually accumulate until it finally fills the entire inflation bag. Then, the soil delivery pipe is used to inject lightweight quick-setting cement mortar into the inflation bag to further compress and solidify the filling soil inside the inflation bag. During the soil replacement process, the central pull rod needs to be locked to keep the shape of the inflation bag unchanged.

[0024] 7) Subsequent related work: After the inflatable bag structure is stable, close the soil delivery device, the first speed limit control valve and the second speed limit control valve. After the subsequent tunnel displacement monitoring results meet the stability requirements, gradually begin to dismantle the relevant structural equipment inside the segment, pull out the sealing plug, perform special sealing treatment on the grouting hole, and the correction work is completed.

[0025] According to the above technical solution, the following technical effects are achieved:

[0026] 1) Can correct deviation in densely packed pipeline spaces

[0027] The method of using an inflatable bag for inflation and extrusion correction can minimize the impact on the surrounding area to the greatest extent, avoiding the great impact on the surrounding environment in traditional sleeve valve pipe grouting, and the possible harm of causing unnecessary deformation of other nearby pipelines or structures. It is suitable for local tunnel displacement correction in underground spaces with dense pipelines.

[0028] 2) The correction form is more flexible

[0029] Since the traditional grouting correction process is irreversible, if the amount of slurry injected is too large, it will lead to excessive correction, and reverse grouting will be required in another direction, causing unnecessary waste, time and effort. However, when using an inflatable bag for correction, the amount of gas injected can be accurately controlled due to the setting of the flow meter and the speed limit control valve. When too much gas is injected, the speed limit control valve on the soil delivery pipe can be opened to release the pressure to avoid excessive correction.

[0030] 3) Can correct tunnel displacement in all directions

[0031] Since each ring of segments is provided with grouting holes at different angles, different grouting holes can be selected for the arrangement of airbags according to the displacement section and displacement direction of the tunnel. For example, when the tunnel sinks and deforms, the airbags can be arranged in the lower half of the segment ring. When the airbags driven into the soil layer begin to inflate and expand, they will squeeze the soil below. Since the force is mutual, the lower soil will generate an upward reaction force, which is used to correct the sinking section of the tunnel back to its original position by "squeezing"; if the tunnel undergoes local floating deformation, the airbags can be arranged in the upper half of the segment ring.

[0032] 4) Accurately correct the local displacement and deformation of the tunnel

[0033] According to the range and displacement value of the tunnel displacement section, different numbers and sizes of air bags can be arranged along the circumferential and longitudinal directions of the tunnel for correction. The longitudinal arrangement principle is based on the midpoint of the displacement section, symmetrical arrangement on both sides, and following the scheme of "dense in the center and sparse on both sides". In addition, since the segments are assembled with staggered seams, the positions of the grouting holes in each ring of the tunnel may be different, so the size and amount of inflation of each air bag in the circumferential direction may be different. While meeting the correction target, it is necessary to ensure that the tunnel does not shift in other directions, that is, the inflation volume of the two air bags on the same ring needs to be calculated to determine a ratio. In actual engineering, real-time displacement monitoring technology is needed to assist in the precise control of the correction amount.

[0034] 5) Simple operation, fast deviation correction, and avoid waste of slurry

[0035] The construction method is simple and quick, and is easy to adopt in operating tunnels. Since the inflatable bag is replaced with soil, the waste of slurry is reduced, and the disadvantage of slurry diffusion in the soil and environmental pollution in traditional sleeve valve tube grouting correction is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 It is a schematic diagram of an inflatable bag structure for displacement correction of an operating subway tunnel provided by an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of the process of driving the inflatable bag into the soil layer in an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the inflation correction process of the airbag in an embodiment of the present invention;

[0040] Figure 4Schematic diagram of the inflatable bag soil replacement process in an embodiment of the present invention;

[0041] Figure 5 is a longitudinal arrangement diagram of the inflatable bags when the tunnel sinks and deforms in an embodiment of the present invention;

[0042] Figure 6 is a lateral arrangement diagram of the inflatable bags when the tunnel sinks and deforms in an embodiment of the present invention;

[0043] Figure 7 is a detailed view of the interior of the inflatable bag when the tunnel sinks and deforms in an embodiment of the present invention;

[0044] Figure 8 It is a longitudinal arrangement diagram of the inflatable bags when the tunnel is deformed upward in the embodiment of the present invention;

[0045] Fig. 9 is a lateral arrangement diagram of the inflatable bags when the tunnel is deformed upward in an embodiment of the present invention;

[0046] Fig.10 It is a detailed view of the interior of the inflatable bag when the tunnel is deformed upward in the embodiment of the present invention;

[0047] Explanation of the reference numerals: pipe segment 1; grouting hole 2; sealing plug 3; air bag 4; telescopic frame 5; conical cap tip 6; center pull rod 7; air filling pipe 8; soil delivery pipe 9; air filling pipe port 10; soil delivery pipe port 11; first speed limit control valve 12; second speed limit control valve 13; first flow meter 14; second flow meter 15; first air pump 16; second air pump 17; soil collecting box 18; filling soil 19. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0049] like Figure 1 As shown, this embodiment provides an inflatable bag structure for correcting the displacement of an operating subway tunnel, including an inflatable bag 4, wherein a central tie rod 7 and a telescopic frame 5 arranged around the central tie rod 7 are arranged inside the inflatable bag 4, a conical cap tip 6 fixedly connected to the central tie rod 7 is arranged on the top, and a sealing plug 3 is connected to the bottom, and a hole is reserved in the center of the sealing plug 3 for the central tie rod 7, an inflation tube 8 and an earth delivery tube 9 to extend into, the inflation tube 8 is supplied with air by an inflation device, and the earth delivery tube 9 is supplied with filling soil 19 by the earth delivery device.

[0050] In this embodiment, the conical cap tip 6 is made of hard metal material, which is convenient for advancement in the grouting hard shell layer and soil.

[0051] In this embodiment, the bottom of the airbag 4 is connected to the sealing plug 3 and fixed together in the grouting hole 2. The telescopic frame 5 is tightly arranged on the inner surface of the airbag 4. A center pull rod 7 is arranged in the center of the airbag 4. The top of the center pull rod 7 is connected to the conical cap tip 6, and the bottom passes through the sealing plug 3, which plays a supporting role for the entire airbag 4 and the telescopic frame 5.

[0052] In this embodiment, the inflation pipe 8 is connected to a first speed limiting control valve 12 and a first flow meter 14, and the soil delivery pipe 9 is connected to a second speed limiting control valve 13 and a second flow meter 15, wherein the speed limiting control valve can control the flow rate of the gas, and the flow meter can monitor the volume of gas flowing through the corresponding pipeline in real time. In this embodiment, the inflation device adopts a first inflation pump 16. In this embodiment, the soil delivery device includes a second inflation pump 17 and a soil collection box 18, and the soil delivery pipe 9 is connected to the second inflation pump 17 and the soil collection box 18 respectively.

[0053] In this embodiment, the telescopic skeleton 5 is arranged at equal angles along the longitudinal direction of the inner surface of the airbag 4. The telescopic skeleton 5 and the airbag 4 can be folded or opened synchronously. The telescopic skeleton 5 is made of a steel material of multiple segments, and the segments are connected by hinges. The telescopic skeleton 5 is divided into a folded state and an opened state. The closed state can be converted into an opened state by pulling the center pull rod 7 downward. Since the telescopic skeleton 5 and the airbag 4 are fixed to each other, the opening of the telescopic skeleton 5 will also cause the airbag 4 to open.

[0054] In this embodiment, when used for the grouting hole 2 of the upper half section of the tunnel, the front end 10 of the air filling pipe 8 and the front end 11 of the soil delivery pipe 9 are 5-8 cm away from the tip of the conical cap, and the front end 10 of the air filling pipe is on the top, and the front end 11 of the soil delivery pipe is on the bottom, and the upper and lower parts are staggered from each other;

[0055] When used for the grouting hole 2 in the lower half section of the tunnel, the front port 10 of the inflation pipe and the front port 11 of the soil delivery pipe are inserted into the inflation bag 4 5-8 cm away from the sealing plug, and the front port 10 of the inflation pipe is on the top and the front port 11 of the soil delivery pipe is on the bottom, staggered from top to bottom.

[0056] In this embodiment, a three-layer anti-backflow device is provided at the front port 10 of the inflation pipe. The three-layer anti-backflow device is composed of a wire mesh, a filter cloth and a wire mesh from top to bottom. In the subsequent soil replacement process, the filling soil 19 can be prevented from entering the inflation pipe 8, ensuring that the inflation pipe 8 will not be blocked.

[0057] In this embodiment, the inflatable bags 4 are arranged in the tunnel displacement section according to the principle of dense in the middle and sparse at both ends. Two inflatable bags 4 are arranged on the same ring tunnel segment 1. The two inflatable bags 4 are arranged on the left and right sides of the tunnel segment 1 respectively. The angle between the position of the left inflatable bag 4 and the vertical direction is α, and the inflation volume is V αThe angle between the right airbag 4 and the vertical direction is β, and the inflation volume is V β , the inflation volume and angle meet The specific inflation volume is determined according to the tunnel's deviation correction displacement.

[0058] like Figure 2 , Figure 3 , Figure 4 Shown is a schematic diagram of various stages of the structure construction of the present invention, wherein Figure 2 In the process of driving the inflatable bag 4 into the soil, the conical cap tip 6 on the top of the inflatable bag 4 is used to push the entire inflatable bag 4 through the grouting hard shell layer and into the soft soil layer with the help of external force. During the pushing process, the telescopic frame 5 is in a closed state. When the specified depth is reached, the sealing plug 3 is embedded and fixed in the grouting hole 2; Figure 3 During the inflation correction process, based on the feedback from the real-time monitoring technology, the inflation tube 8 is used to inflate the airbag 4, causing the airbag 4 to expand. The central pull rod 7 is slowly pulled downward according to the volume of the inflated gas, so that the telescopic frame 5 gradually opens. During this process, the telescopic frame 5 stabilizes and supports the structure of the airbag 4, preventing it from deforming irregularly during the inflation process, thereby ensuring the quality of the correction. Figure 4 In the process of replacing the soil, the filling soil 19 is sent into the air bag 4 through the soil delivery pipe 9 by using high-pressure gas. At the same time, the air bag 8 on the other side discharges the excess gas. The speed limiting control valves and flow meters on both sides are used to ensure that the volume of the high-pressure gas filled into the soil delivery pipe 9 is equal to the volume of the gas discharged from the air bag 8, so as to maintain the balance of the gas volume in the air bag 4. In addition, since the air bag port 10 is provided with an anti-backflow device, the soil entering the air bag 4 will not be discharged from the air bag 8 along with the high-pressure gas, but will remain in the air bag 4 permanently until the entire air bag 4 is filled.

[0059] like Figure 5 , Figure 6 , Figure 7 As shown in the figure, when the tunnel sinks and deforms in the longitudinal direction, the following Figure 5 As shown, the inflatable bags 4 are arranged longitudinally, the inflatable bags 4 are arranged in the lower half of the tube segment 1, and are arranged symmetrically along the center of the sinking deformation section. The number of inflatable bags 4 is dense in the middle and sparse at both ends. During the inflation correction process, the inflatable bags 4 in the middle are inflated symmetrically to both sides in the specific order of a, b, c, d, and e. Figure 6The arrangement scheme of the airbag 4 along the circumferential direction of the segment 1 is as follows. Since there is a ballast at the bottom of the segment, the grouting holes 2 closest to the two sides of the ballast can be selected for the arrangement of the airbag 4. The grouting holes 2 on both sides are often asymmetrical. In order to ensure that the airbag 4 does not undergo additional horizontal deformation during the process of correcting the tunnel sinking deformation, an asymmetric inflation correction scheme is required, that is, the inflation amount of the airbags 4 on both sides should be different. For a specific example, let the angle between the left airbag 4 and the vertical be α, and the angle between the right airbag 4 and the vertical be β, and let α>β. In order to ensure that no additional horizontal deformation occurs, the radius R1 of the left airbag 4 should be smaller than the radius R2 of the right airbag 4, that is, the inflation amount V of the left airbag 4 α Less than the inflation volume V of the right airbag 4 β , specifically meet like Figure 7 Shown is a detailed view of the interior of the air bag 4. Since the air bag 4 is arranged in the lower half of the pipe segment 1, the air pipe port 10 and the soil delivery pipe port 11 are inserted into the air bag 4 shallowly, with a depth of only 5-8 mm, and the two ports are staggered up and down, with the air pipe port 10 on the top and the soil delivery pipe port 11 on the bottom.

[0060] like Figure 8 , Fig. 9 , Fig.10 As shown in the figure, when the tunnel is deformed in the longitudinal direction, the following Figure 8 As shown, the inflatable bags 4 are arranged longitudinally, the inflatable bags 4 are arranged in the upper half of the tube segment 1, and are arranged symmetrically along the center of the floating deformation section. The number of inflatable bags 4 is dense in the middle and sparse at both ends. During the inflation correction process, the inflatable bags 4 in the middle are inflated symmetrically in sequence to both sides. The specific order is a, b, c, d, e. Fig. 9 For the arrangement of the airbags 4 along the circumferential direction of the pipe segment 1, the grouting holes 2 closest to the vault on both sides are selected for the arrangement of the airbags 4. The grouting holes 2 on both sides are often asymmetrical. In order to ensure that the airbags 4 do not undergo additional horizontal deformation during the process of correcting the upward deformation of the tunnel, an asymmetric inflation correction scheme is required, that is, the inflation amounts of the airbags 4 on both sides should be different. For a specific example, let the angle between the left airbag 4 and the vertical be α, and the angle between the right airbag 4 and the vertical be β, and let α>β. In order to ensure that no additional horizontal deformation occurs, the radius R1 of the left airbag 4 should be smaller than the radius R2 of the right airbag 4, that is, the inflation amount V of the left airbag 4 α Less than the inflation volume V of the right airbag 4 β , specifically meet like Fig.10The figure shows the details of the interior of the air bag 4. Since the air bag 4 is arranged in the upper half of the pipe segment 1, the air pipe port 10 and the soil delivery pipe port 11 are inserted deeper into the air bag 4, and the distance from the top conical cap tip 6 is 5-8mm, and the two ports are staggered up and down, with the air pipe port 10 on the top and the soil delivery pipe port 11 on the bottom.

[0061] This embodiment also provides a construction method for a displacement correction airbag structure for an operating subway tunnel, comprising the following steps:

[0062] 1) Measurement and layout design: Measure the length and deformation of the tunnel deformation section, mark the available grouting holes 2 within the section, measure the angles of the grouting holes 2 on both sides of the same segment 1, and use a dense arrangement in the middle and sparse arrangement at both ends of the longitudinal direction of the tunnel. After calculation and analysis, the number, spacing and range of the inflatable bags 4 are reasonably designed;

[0063] 2) Production of the inflatable bag 4: prepare the inflatable pipe 8 and the soil delivery pipe 9, put an anti-backflow device on the inflatable pipe port 10, and use the three-layer material of "wire mesh + filter cloth + wire mesh" to tie and make it. Then, pass the inflatable pipe 8 and the soil delivery pipe 9 through the small hole on the sealing plug 3 and insert them into the inflatable bag 4. Select a suitable insertion depth according to the use position of the inflatable bag 4. After assembly, apply waterproof paint on the internal channel and side of the sealing plug 3 and put it aside for use;

[0064] 3) Insertion of the airbag 4: Before driving into the grouting hole 2, the airbag 4 is in a folded state, and the airbag 4 is pushed into the grouting hole 2 by means of thrust, and the 7-14 cm thick grouting hard shell layer on the surface of the pipe segment 1 is penetrated by means of the conical cap tip 6 on the top of the airbag 4. Then, the airbag 4 is pushed into the soft soil layer outside the grouting hard shell layer as a whole. When the specified depth is reached, the sealing plug 3 is embedded and fixed in the grouting hole 2, and the inner surface of the sealing plug 3 is coated with slurry for waterproofing. The above operation is repeated until all the airbags 4 are driven into the specified grouting hole 2;

[0065] 4) Inflation correction process: With the real-time tunnel monitoring technology, open the first inflation pump 16 and the first speed control valve 12, close the second speed control valve 13, and start to inflate using the corresponding inflation tube 8 on each inflatable bag 4. During the inflation process, make full use of the first speed control valve 12 and the first flow meter 14, and pay strict attention to the inflation volume and inflation speed of each inflatable bag 4. The inflation volume of the two circumferential inflatable bags 4 is limited according to the inflation volume ratio calculated according to the layout angle, that is, the inflation volume meets The inflation process is carried out synchronously according to the requirements. First, the airbags 4 near the center of the deformation zone are inflated and corrected along the longitudinal direction of the tunnel, and then they are gradually inflated symmetrically on both sides. That is, the two airbags 4 of the most central ring are inflated first, and then the four airbags 4 on both sides of the central ring are inflated, and so on. It is worth noting that the information feedback of real-time monitoring technology is required during the inflation process to ensure the accuracy of the correction amount. The inflation amount of each airbag 4 is adjusted according to the actual correction situation of the tunnel and the displacement monitoring data. During this period, if the airbags 4 of a certain ring are over-inflated, the two airbags 4 of the same ring need to be exhausted at the same time to ensure that the two airbags 4 of the same ring always maintain the initial design ratio. In addition, during the inflation process of each airbag 4, the telescopic skeleton 5 inside will gradually open to stabilize the shape of the airbag 4.

[0066] 5) Tunnel deformation recovery: After the tunnel deviation correction is completed, first close the first speed limit control valve 12 and the first air pump 16 of each airbag 4 to ensure that the shape and gas volume of the airbag 4 remain unchanged, stabilize for a period of time, and wait for the tunnel longitudinal deformation to recover;

[0067] 6) Soil replacement process: After the longitudinal deformation of the tunnel is restored, first turn on the second air pump 17 to suck the filling soil 19 into the soil delivery pipe 9 through high-pressure gas, then slowly and synchronously open the second speed limit control valve 13 and the first speed limit control valve 12, closely observe the readings of the second flow meter 15 and the first flow meter 14, strictly control the volume of gas sent into the soil delivery pipe 9 to be equal to the volume of gas discharged from the inflation pipe 8, and maintain the size of the inflation bag 4 unchanged. When the filling soil 19 is sent into the interior of the inflation bag 4, due to the design of the inflation pipe port 10, the filling soil 19 is sucked into the filling soil 19 into the filling soil 19. An anti-back-sucking device is installed, so the filling soil 19 will not be sucked into the inflation tube 8. As the ventilation process proceeds, the filling soil 19 inside the inflation bag 8 will gradually accumulate until it finally fills the entire inflation bag 4. Then, the soil delivery pipe 9 is used to inject lightweight quick-setting cement mortar into the inflation bag 4 to further compress and solidify the filling soil 19 inside the inflation bag 4. In the process of replacing the soil, the central pull rod 7 needs to be locked, that is, the opening degree of the telescopic frame 5 is maintained unchanged, the shape of the inflation bag 4 is maintained unchanged, and the quality of the correction is ensured;

[0068] 7) Subsequent related work: After the structure of the air bag 4 is stable, the second air pump 17, the first speed limit control valve 12 and the second speed limit control valve 13 are closed, and the inside of the air bag 4 behind the wall of the segment 1 is changed from high-pressure gas to filling soil 19. Since the filling soil 19 has the same soil quality as the surrounding soil layer, it can ensure the stability of the tunnel after correction. After the later monitoring results meet the stability requirements, the relevant structural equipment inside the segment 1 is gradually dismantled, the sealing plug 3 is pulled out, and the grouting hole 2 is specially sealed, and the correction work is completed.

[0069] The present invention is suitable for local displacement correction in all directions of an operating subway tunnel in a soft soil area, especially when there are multiple pipelines in a narrow underground space, in order to avoid excessive impact on other surrounding pipelines while requiring accurate correction of the correction target.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A construction method for a displacement correction inflatable bag structure for an operating subway tunnel, characterized in that: The inflatable bag structure for correcting displacement of an operating subway tunnel comprises an inflatable bag, wherein a central tie rod and a telescopic frame arranged around the central tie rod are arranged inside the inflatable bag, a conical cap tip fixedly connected to the central tie rod is arranged on the top, and a sealing plug is connected to the bottom, a hole is reserved in the center of the sealing plug for the central tie rod, an inflatable pipe and a soil delivery pipe to extend into, the inflatable pipe is supplied with air by an inflating device, and the soil delivery pipe is supplied with filling soil by the soil delivery device; a first speed limit control valve and a first flow meter are connected to the inflatable pipe, and a second speed limit control valve and a second flow meter are connected to the soil delivery pipe; The method comprises the following steps: 1) Measurement and layout design: Measure the length and deformation of the tunnel deformation section, mark the available grouting holes within the section, measure the angles α and β between the grouting holes on the left and right sides of the same ring of the tunnel and the vertical direction, and determine the number, spacing and range of the inflatable bags through calculation and analysis; 2) Production of the inflatable bag: Put an anti-backflow device on the end of the inflatable pipe, insert the inflatable pipe and the soil delivery pipe through the small hole on the sealing plug and into the inflatable bag. Select the appropriate insertion depth according to the use position of the inflatable bag. After assembly, apply waterproof coating on the internal channel and side of the sealing plug; 3) Insertion of the inflatable bag: Push the folded inflatable bag into the grouting hole. When it is inserted into the specified depth of the soft soil layer behind the wall, insert and fix the sealing plug into the grouting hole, apply slurry to the inner surface of the sealing plug for waterproofing, and repeat the above operation until all the inflatable bags are driven into the specified grouting holes; 4) Inflation correction process: With the real-time tunnel monitoring technology, open the inflation device and the first speed control valve, close the second speed control valve, and start to inflate using the corresponding inflation tube on each inflatable bag. During the inflation process, make full use of the first speed control valve and the first flow meter, and pay strict attention to the inflation volume and inflation speed of each inflatable bag. The inflation volume of the two circumferential inflatable bags should be adjusted according to the The inflation process is carried out synchronously. First, the inflatable bag near the center of the deformation zone is inflated and corrected along the longitudinal direction of the tunnel, and then it is gradually inflated symmetrically on both sides. During the inflation process of each inflatable bag, the internal telescopic frame is gradually opened; 5) Tunnel deformation recovery: After the tunnel deviation correction is completed, first close the first speed limit control valve and inflation device of each inflatable bag, stabilize for a period of time, and wait for the tunnel longitudinal deformation to recover; 6) Soil replacement process: After the longitudinal deformation of the tunnel is restored, the soil delivery device is first turned on to suck the filling soil into the soil delivery pipe through high-pressure gas. Then, the second speed limit control valve and the first speed limit control valve are slowly opened synchronously. The indications of the second flow meter and the first flow meter are closely observed. The volume of gas delivered by the soil delivery pipe is strictly controlled to be equal to the volume of gas discharged by the inflation pipe to maintain the size of the inflation bag unchanged. As the gas replacement process proceeds, the filling soil inside the inflation bag will gradually accumulate until it finally fills the entire inflation bag. Then, the soil delivery pipe is used to inject lightweight quick-setting cement mortar into the inflation bag to further compress and solidify the filling soil inside the inflation bag. During the soil replacement process, the central pull rod needs to be locked to keep the shape of the inflation bag unchanged. 7) Subsequent related work: After the inflatable bag structure is stable, close the soil delivery device, the first speed limit control valve and the second speed limit control valve. After the subsequent tunnel displacement monitoring results meet the stability requirements, gradually begin to dismantle the relevant structural equipment inside the segment, pull out the sealing plug, perform special sealing treatment on the grouting hole, and the correction work is completed.

2. The method according to claim 1, characterized in that The inflation device adopts a first inflation pump.

3. The method according to claim 1, characterized in that The soil delivery device comprises a second air pump and a soil collecting box, and the soil delivery pipe is connected to the second air pump and the soil collecting box respectively.

4. The method according to claim 1, characterized in that: The telescopic frame is arranged at equal angles along the longitudinal direction of the inner surface of the inflatable bag, and the telescopic frame and the inflatable bag can be folded or opened synchronously.

5. The method according to claim 1, characterized in that The telescopic frame is made of steel material and is divided into a plurality of sections. The sections are connected by hinges. The telescopic frame can be divided into a folded state and an extended state.

6. The method according to claim 1, characterized in that When used for grouting holes in the upper half of the tunnel, the front end of the air pipe and the front end of the soil delivery pipe are 5-8 cm away from the tip of the conical cap, and the front end of the air pipe is on the top and the front end of the soil delivery pipe is on the bottom, staggered from top to bottom; When used for grouting holes in the lower half of the tunnel section, the front ports of the inflation tube and the soil delivery tube are inserted into the inflation bag 5-8 cm away from the sealing plug, and the front port of the inflation tube is on top and the front port of the soil delivery tube is on the bottom, staggered from top to bottom.

7. The method according to claim 1, characterized in that A three-layer anti-backsucking device is arranged at the front end of the inflation tube, and the three-layer anti-backsucking device is composed of a wire mesh, a filter cloth and a wire mesh in order from top to bottom.

8. The method according to claim 1, characterized in that The inflatable bags are arranged in the tunnel displacement section according to the principle of dense in the middle and sparse at both ends. Two inflatable bags are arranged on the same ring tunnel segment. The two inflatable bags are arranged on the left and right sides of the tunnel segment respectively. The angle between the position of the left inflatable bag and the vertical direction is α, and the inflation volume is V α , the angle between the right airbag and the vertical direction is β, and the inflation volume is V β , the inflation volume and angle meet The specific inflation volume is determined according to the tunnel's deviation correction displacement.

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