A multi-pipe synchronous grouting device capable of sectional hole sealing and a construction method thereof

Abstract

The application discloses a kind of segmented hole sealing multi-tube synchronous grouting device and construction method, belong to grouting equipment technical field, including multiple grouting pipes, multiple segmented covers, multiple segmented membrane bags and multiple pressure valves;Multiple segmented covers are set on multiple grouting pipes according to preset grouting section distance interval along grouting pipe length direction;Each grouting pipe includes inlet section pipe body and outlet section pipe body, inlet section pipe body is provided with membrane bag inlet, outlet section pipe body is provided with grouting port, and the membrane bag inlet and grouting port of each grouting pipe are set according to preset grouting section distance interval;Each segmented membrane bag is located at adjacent grouting section boundary and wraps corresponding membrane bag inlet;Each pressure valve is installed inside grouting pipe and located in the pipe section covered by segmented membrane bag, and the pressure valve is configured to: when the pressure of liquid in the pipe is less than the set threshold, it is closed, and it is opened and kept irreversible opening after exceeding the threshold.The application realizes reliable segmented hole sealing, prevents grouting and multi-tube synchronous grouting, improves construction efficiency and grouting quality.

Description

Technical Field

[0001] This invention relates to the field of grouting equipment technology, specifically to a multi-pipe synchronous grouting device and construction method with segmented sealing capability. Background Technology

[0002] When aquifers are distributed in multiple layers or fractures are unevenly developed, a single grouting of the entire borehole is unlikely to effectively deliver the grout to the target layer and is prone to grout waste. Existing technologies often employ segmented grouting, which divides a long borehole into several independent sections along its depth and injects grout into each section to seal groundwater and reinforce the surrounding rock. The key is reliable isolation between the sections to prevent grout cross-contamination.

[0003] Currently, quick-setting cement or chemical grout is often used for segmented sealing of holes. However, there are problems such as difficulty in matching the setting time with the grouting rhythm, insufficient bonding strength between the sealing body and the hole wall, and easy formation of gaps after drying shrinkage, leading to grout leakage. Furthermore, existing segmented grouting methods mostly rely on single-pipe systems, and when multiple pipes are used simultaneously, there is a lack of independent sealing structures. This makes it easy for grout to cross-contaminate and mix in different grouting sections, leading to the failure of segmented grouting. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a multi-pipe synchronous grouting device and construction method with segmented sealing, which realizes reliable segmented sealing, prevention of grout cross-contamination, and multi-pipe synchronous grouting, thereby improving construction efficiency and grouting quality.

[0005] The technical solution of the present invention is as follows: In a first aspect of the present invention, a multi-pipe synchronous grouting device with segmented sealing is provided, comprising multiple grouting pipes, multiple segmented sealing caps, multiple segmented membrane bags, and multiple pressure valves; The multiple segmented caps are arranged at intervals along the length of the grouting pipe according to the preset grouting segment distance; Each grouting pipe includes an inlet section and an outlet section. The inlet section has a membrane bag inlet, and the outlet section has a grouting port. The membrane bag inlet and the grouting port of each grouting pipe are spaced apart according to the preset grouting section distance. Each segmented membrane bag is installed outside multiple grouting pipes at the boundary between two adjacent grouting sections, and wraps the membrane bag inlet on the grouting pipe at that grouting section; Each pressure valve is installed inside the grouting pipe and located within the pipe section covered by the segmented membrane bag. The pressure valve is configured to close when the liquid pressure in the grouting pipe where the pressure valve is located is less than a set threshold, and to open when the liquid pressure in the grouting pipe where the pressure valve is located exceeds the set threshold, and to remain in an irreversible open state.

[0006] In some embodiments of the present invention, the plurality of grouting pipes are arranged parallel to each other along the length direction, and each segmented cap has through holes equal to the number of grouting pipes. Each grouting pipe passes through the corresponding through hole of each segmented cap and is sealed to the segmented cap.

[0007] In some embodiments of the present invention, the segmented cap includes a cap body, the cap body is configured as a disc-shaped structure, the diameter of the cap body is smaller than the diameter of the required grouting hole, and the cap body is provided with a plurality of through holes along the axial direction, the plurality of through holes being centrally symmetrically distributed on the cap body.

[0008] In some embodiments of the present invention, the segmented membrane bag includes a grouting membrane bag, which covers the membrane bag inlet on the grouting pipe at the grouting section. The interior of the grouting membrane bag communicates with the interior of the grouting pipe through the membrane bag inlet, and the contact parts between the grouting membrane bag and multiple grouting pipes are sealed.

[0009] In some embodiments of the present invention, the grouting membrane bag is filled with expanding granular balls, which are made of high molecular weight water-absorbing material particles that increase in volume when exposed to water, and the outer diameter of the grouting membrane bag after expansion is larger than the diameter of the required grouting hole.

[0010] In some embodiments of the present invention, the pressure valve includes a pressure valve inlet and a pressure valve outlet. The pressure valve inlet is connected to the inlet section of the pipe body, and the pressure valve outlet is connected to the outlet section of the pipe body. A valve core is provided in the middle of the pressure valve inlet and the pressure valve outlet. The valve core is configured such that: when the liquid pressure in the grouting pipe is less than a set threshold, the valve core is closed, and the channel between the pressure valve inlet and the pressure valve outlet is closed; when the liquid pressure in the grouting pipe is greater than the set threshold, the valve core is opened and remains in an irreversible open state, and the channel between the pressure valve inlet and the pressure valve outlet is opened.

[0011] In some embodiments of the present invention, the valve core includes a valve core seat, and two valve core seats are provided, which are symmetrically installed on the inner wall of the grouting pipe. A valve core sleeve is provided at one end of each valve core seat facing the axis of the grouting pipe. A one-way locking structure is provided between the valve core sleeve and the valve core seat. A sealing gasket is provided at one end of each valve core sleeve facing the axis of the grouting pipe, and the two sealing gaskets abut against each other. A spring is provided inside the valve core sleeve. One end of the spring abuts against the valve core seat, and the other end of the spring abuts against the valve core sleeve.

[0012] In some embodiments of the present invention, the one-way locking structure specifically comprises: The valve core sleeve is provided with a pawl at one end facing the valve core seat. The valve core seat is provided with a groove-shaped structure along the radial direction of the grouting pipe inside. The groove-shaped structure is provided with a rack that engages with the pawl. The pawl and the rack mesh to form a one-way locking structure. This one-way locking structure only allows the valve core sleeve to move in one direction in the opening direction, and reverse movement is locked.

[0013] In some embodiments of the present invention, a first guide slope is provided at the inlet of the pressure valve, and the first guide slope gradually extends from the inlet end of the pressure valve toward the sealing gasket. The pressure valve outlet is provided with a second flow guide slope, which gradually extends from the pressure valve outlet end towards the sealing gasket.

[0014] In a second aspect of the invention, a multi-pipe synchronous grouting construction method with segmented sealing is provided, employing the aforementioned multi-pipe synchronous grouting device with segmented sealing, comprising: Drill grouting holes; Set the opening pressure of the pressure valve in each grouting pipe to a preset threshold. Segmented membrane bags are installed at the inlet of each grouting pipe, and expanded granular balls are filled into the segmented membrane bags; Multiple grouting pipes are passed through the through holes of each section of the cap and lowered into the grouting holes in order from deep to shallow, so that the grouting port of each grouting pipe is located at the depth of the corresponding grouting section. Water is injected into the grouting pipe at a pressure lower than the opening pressure of the pressure valve. The water is maintained so that it enters the segmented membrane bag through the membrane bag inlet. The expanded granules absorb water and expand, causing the segmented membrane bag to tighten the wall of the grouting hole, thus achieving segmented sealing. Increase the water injection pressure to exceed the opening pressure of the pressure valve, causing the pressure valve to open irreversibly. Switch the injection medium from water to grouting material and continue grouting until the design termination standard is met.

[0015] One or more technical solutions of the present invention have the following beneficial effects: By employing a combination of segmented membrane bags and expanding granular balls, and injecting low-pressure water into the grouting pipe during construction, the water enters the segmented membrane bags through the inlet. Upon contact with the water, the expanding granular balls passively absorb water and expand, causing the segmented membrane bags to evenly expand and tightly adhere to the grouting hole wall. Since the expansion medium is water rather than grout, the problem of mismatched setting time between traditional fast-setting cement or chemical grout and the grouting rhythm is completely avoided. This prevents clogging of the grouting pipe or pressure valve due to premature grout setting, and also avoids forced waiting due to slow setting. Simultaneously, the hydrogel formed after the expanding granular balls absorb water has a stable volume and a certain degree of elasticity, maintaining its expansion state without relying on continuous injection pressure. It will not shrink due to pressure fluctuations or drops, fundamentally solving the problem of grout leakage caused by gaps resulting from the drying shrinkage of the sealing body, significantly improving the reliability and durability of segmented sealing.

[0016] Secondly, by using multiple grouting pipes in conjunction with multiple segmented caps and multiple segmented membrane bags, simultaneous segmented grouting of multiple pipes within a single borehole is achieved. Each segmented membrane bag independently forms a reliable seal at the boundary of each grouting segment, and together with the orifice seal of the segmented caps, provides an independent sealing structure between different grouting segments, completely solving the problems of grout cross-contamination and mixing that easily occur during simultaneous multi-pipe grouting. Multiple grouting pipes can simultaneously inject grout into different grouting segments, significantly improving construction efficiency and enabling segmented grouting to truly achieve efficient, reliable, and low-cost engineering applications.

[0017] Furthermore, irreversible pressure valves are installed inside each grouting pipe at the sections covered by segmented membrane bags. These valves remain closed when the liquid pressure inside the pipe is below a set threshold, ensuring that water flow during the low-pressure injection phase can only enter the segmented membrane bags to complete the sealing. After sealing is completed, as the water pressure increases, the pressure valves exceed the threshold and open, maintaining an irreversible open state through a one-way locking structure. This design avoids the grout pulses caused by the repeated opening and closing of ordinary pressure valves during grouting pressure fluctuations, ensuring continuous stability of grout flow and pressure during subsequent grouting processes. This allows the grout to diffuse evenly to the target formation, effectively improving the grouting, water plugging, and reinforcement effects. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a multi-pipe synchronous grouting device with segmented sealing provided in Embodiment 1 of the present invention; Figure 2 This is a cross-sectional schematic diagram of a multi-pipe synchronous grouting device with segmented sealing provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the grouting pipe provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the segmented cap structure provided in Embodiment 1 of the present invention; Figure 5This is a schematic diagram of the pressure valve provided in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the pressure valve after it is opened, as provided in Embodiment 1 of the present invention.

[0019] In the diagram: 1. Grouting pipe; 11. Inlet section pipe body; 12. Outlet section pipe body; 13. Membrane bag inlet; 14. Grouting port; 2. Segmented cover; 21. Cover body; 22. Through hole; 3. Segmented membrane bag; 31. Grouting membrane bag; 32. Expanding granular ball; 4. Pressure valve; 41. Pressure valve inlet; 42. Pressure valve outlet; 43. Valve core sleeve; 44. Sealing gasket; 45. Spring; 46. Valve core seat; 47. One-way locking structure. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Example In a typical embodiment of the present invention, such as Figure 1 , Figure 2 As shown in the figure, this embodiment provides a multi-pipe synchronous grouting device with segmented sealing, including multiple grouting pipes 1, multiple segmented caps 2, multiple segmented membrane bags 3 and multiple pressure valves 4. This device is used for segmented grouting construction in water-rich soft strata such as tunnels, mines, and deep foundation pits. Its core lies in achieving reliable inter-segment isolation during multi-pipe synchronous grouting through the combination of mechanical structure and construction technology.

[0022] Multiple segmented caps 2 are spaced apart along the length of the grouting pipes 1 according to a preset grouting segment distance, dividing the entire grouting hole into multiple independent grouting segments. The multiple grouting pipes 1 are arranged parallel to each other along their length. Each segmented cap 2 has a number of through holes 22 equal to the number of grouting pipes 1. Each grouting pipe 1 passes through the corresponding through hole 22 of its respective segmented cap 2 and is sealed to it. The segmented cap 2 includes a cover body 21, which is a disc-shaped structure with a diameter smaller than the diameter of the required grouting hole to facilitate the smooth insertion of the entire device into the hole. Multiple through holes 22 are axially oriented through the cover body 21, and these through holes 22 are centrally symmetrically distributed on the cover body 21, ensuring uniform stress on each grouting pipe 1.

[0023] Each grouting pipe 1 includes an inlet section 11 and an outlet section 12. The inlet section 11 has a membrane bag inlet 13, and the outlet section 12 has a grouting port 14. The membrane bag inlet 13 and the grouting port 14 of each grouting pipe 1 are spaced apart according to a preset grouting section distance. The grouting pipe 1 can be of equal length, with the membrane bag inlet 13 and grouting port 14 opened at different depths to achieve segmented coverage, or it can be grouting pipes 1 of different lengths.

[0024] The membrane bag inlet 13 is usually a series of small holes distributed around the circumference of the tube to ensure that the liquid flows smoothly into the segmented membrane bag 3.

[0025] Grouting inlets 14 are located at the lower part of the outlet section pipe body 12. They can be multiple sets of perforated openings distributed along the pipe's axial direction. Each set of perforated openings includes multiple circular holes evenly distributed circumferentially. Adjacent sets of holes are staggered to ensure uniform diffusion of the grout to the surrounding strata. After the grouting material passes through the pressure valve 4, it is ejected from the grouting inlets 14 through the outlet section pipe body 12 and injected into formation fractures or pores. The location of the grouting inlets 14 determines the depth range of the grouting section handled by the grouting pipe 1 and needs to be determined based on geological surveys.

[0026] Each segmented geomembrane bag 3 is respectively installed outside multiple grouting pipes 1 at the boundary between two adjacent grouting sections, and wraps the geomembrane bag inlet 13 on the grouting pipe 1 at that grouting section. The segmented geomembrane bag 3 includes a grouting geomembrane bag 31 and an expanding granular ball 32. The grouting geomembrane bag 31 is made of a high-strength, flexible, and impermeable material, such as rubber, polyester fiber cloth, or composite geomembrane.

[0027] The grouting membrane bag 31 wraps around the inlet 13 of the membrane bag, and the inside of the membrane bag is connected to the inside of the grouting pipe 1 through the inlet 13 of the membrane bag. The contact parts between the grouting membrane bag 31 and the multiple grouting pipes 1 are sealed. The sealing method can be clamp binding or heat shrink tubing sealing.

[0028] The grouting membrane bag 31 is filled with expanding granular balls 32, which are superabsorbent polymer particles that expand in volume upon contact with water, such as sodium polyacrylate superabsorbent resin. This material can absorb hundreds of times its own weight in water, and expands rapidly after absorbing water to form a hydrogel. When it has not absorbed water, its overall outer diameter is smaller than the diameter of the grouting hole, making it easy to lower; after absorbing water, its expanded outer diameter is larger than the diameter of the grouting hole, thus tightly adhering to the hole wall to achieve inter-segment sealing.

[0029] Each pressure valve 4 is installed inside the grouting pipe 1 and located within the pipe section covered by the segmented membrane bag 3. The pressure valve 4 includes a pressure valve inlet 41 and a pressure valve outlet 42. The pressure valve inlet 41 is connected to the inlet section pipe body 11, and the pressure valve outlet 42 is connected to the outlet section pipe body 12. A valve core is provided in the middle.

[0030] The valve core is configured such that when the liquid pressure in the grouting pipe 1 is less than a set threshold, the channel is closed; when it is greater than the set threshold, it is opened and remains irreversibly open. This configuration achieves the sequence of sealing the hole before grouting. During the low-pressure water injection stage, water cannot pass through the pressure valve 4 and can only enter the segmented membrane bag 3 through the membrane bag inlet 13 to expand the membrane bag and seal the hole. After sealing, the pressure is increased, the pressure valve 4 opens, and the subsequent grouting material can pass smoothly. The set threshold of the pressure valve 4 can be adjusted according to project needs, usually by selecting springs 45 with different elastic coefficients or adjusting the pre-compression amount.

[0031] An improved segmented grouting scheme exists, employing multiple grouting pipes of varying lengths simultaneously inserted into the same borehole, each pipe corresponding to a grouting segment. During construction, cement grout is first injected into a membrane bag to expand and tighten it against the borehole wall, achieving segmented sealing. Then, a pressure valve is opened to inject more cement grout. The expansion of the membrane bag and the opening of the valve are both accomplished using the same grout. However, this scheme still has shortcomings: If the grout directly expands into the membrane bag, it may clog the valve or grouting pipe if it solidifies too quickly, or it may clog the valve or grouting pipe if it solidifies too slowly. This will affect the rhythm of the process after sealing the hole. Furthermore, the pressure drop after the membrane bag expands may cause it to shrink back, resulting in insufficient sealing reliability. At the same time, ordinary pressure valves may open and close repeatedly when the pressure fluctuates, causing grout pulses. This will lead to unstable grouting flow and pressure, resulting in uneven grout diffusion in the formation and affecting the water plugging and reinforcement effects.

[0032] The device in this embodiment employs a two-step process of water followed by slurry, using water as the expansion medium for the membrane bag, completely avoiding the influence of slurry solidification time on the sealing rhythm. The expanding granular balls 32 passively expand upon contact with water, maintaining their expanded state without relying on continuous pressure, and will not shrink back due to pressure drops. The pressure valve 4 uses a one-way locking structure 47 to achieve irreversible opening; once opened, it remains permanently open, avoiding repeated opening and closing and slurry pulses caused by pressure fluctuations. The simultaneous operation of multiple grouting pipes 1 significantly improves construction efficiency, and the segmented caps 2 and segmented membrane bags 3 work together to form a double seal, effectively preventing slurry cross-contamination between segments.

[0033] The valve core includes two valve core seats 46, which are symmetrically installed on the inner wall of the grouting pipe 1. Each of the two valve core seats 46 has a valve core sleeve 43 at its end facing the axis of the grouting pipe 1, and a one-way locking structure 47 is provided between the valve core sleeve 43 and the valve core seat 46. Each of the two valve core sleeves 43 has a sealing gasket 44 at its end facing the axis of the grouting pipe 1, and the two sealing gaskets 44 abut against each other. A spring 45 is provided inside the valve core sleeve 43, with one end of the spring 45 abutting against the valve core seat 46 and the other end abutting against the valve core sleeve 43.

[0034] This symmetrical valve core structure experiences balanced forces. Two sealing gaskets 44, pushed by the spring 45, fit together at the center to form a reliable seal. The sealing gaskets 44 are made of elastic materials such as rubber or polyurethane. When liquid pressure acts on the back of the sealing gaskets 44, generating a thrust, the valve closes when the thrust is less than the preload of the spring 45; otherwise, the two valve core sleeves 43 separate, opening the flow channel. The preload of the spring 45 determines the opening threshold, which can be precisely set by selecting springs of different stiffness or adjusting the compression.

[0035] The valve core sleeve 43 is provided with a pawl at one end facing the valve core seat 46. The valve core seat 46 is provided with a groove structure along the radial direction of the grouting pipe 1 inside. The groove structure is provided with a rack that cooperates with the pawl. The pawl and the rack mesh to form a one-way locking structure 47, which only allows the valve core sleeve 43 to move in one direction in the opening direction, and is locked when moving in the opposite direction.

[0036] When the valve core sleeve 43 moves outward under the pressure of the liquid, the pawl slides along the helical tooth surface of the rack. When the pressure drops, the tip of the pawl abuts against the tooth surface of the rack to prevent reverse movement. This mechanical one-way locking structure is simple and reliable, requiring no external power source. Due to the function of the one-way locking structure 47, once the pressure valve 4 is opened, it remains permanently open. Even if the pressure fluctuates during subsequent grouting, it will not repeatedly open and close, eliminating grout pulses and ensuring the stability of grouting flow and pressure.

[0037] A first flow guiding slope is provided at the pressure valve inlet 41, which gradually extends from the inner wall end of the pressure valve inlet 41 toward the sealing gasket 44; a second flow guiding slope is provided at the pressure valve outlet 42, which gradually extends from the inner wall end of the pressure valve outlet 42 toward the sealing gasket 44.

[0038] The first guide slope is designed to guide the low-pressure injection water to flow smoothly to the membrane bag inlet 13 when the pressure valve 4 is closed, thereby reducing hydraulic loss.

[0039] like Figure 5 As shown, when the water pressure gradually increases, the upper valve core sleeve 43 has an annular pressure-bearing part at one end facing the sealing gasket 44. The first guide slope guides the water flow and cooperates with the annular pressure-bearing part, so that the annular pressure-bearing part is subjected to an upward thrust. When the water pressure increases to the point that the upward thrust is greater than the preload of the upper spring 45, the upper valve core sleeve 43 gradually moves upward and locks in the reverse direction. At this time, the water pressure fills the upper cavity, and the lower valve core sleeve 43 is subjected to a downward thrust under the action of water pressure. When the water pressure increases to the point that the downward thrust is greater than the preload of the lower spring 45, the lower valve core sleeve 43 gradually moves downward and locks in the reverse direction, thereby realizing the opening of the pressure valve 4. Figure 6 As shown.

[0040] After pressure valve 4 is opened, the second guide slope can guide the subsequent water flow or the grout flow during grouting, reducing local resistance to grout flow, lowering pressure loss, and allowing the grout to be injected into the formation with a more stable pressure and flow rate. In addition, the first and second guide slopes can also reduce grout retention and deposition inside the valve body, reducing the risk of blockage and improving the reliability of the device.

[0041] This embodiment also provides a multi-pipe synchronous grouting construction method with segmented sealing, which is carried out using the above-mentioned device.

[0042] The method includes: drilling grouting holes; setting the opening pressure of the pressure valve; installing segmented membrane bags and filling them with expanded granular balls; lowering and positioning the grouting pipes from deep to shallow; connecting the grouting pump; injecting water at low pressure to expand the membrane bags and seal the holes; irreversibly opening the pressure valve by increasing the pressure; and switching the grouting material to grout until the termination standard is met. When drilling grouting holes, the hole location, depth, and number of segments are determined based on geological data. The hole diameter is larger than the diameter of the segmented cap 2. After drilling to the designed depth, the hole is cleaned. The pressure valve opening pressure setting steps are as follows: each pressure valve 4 is tested on the ground. The opening pressure of the pressure valve is set by selecting the spring 45 and adjusting the pre-compression amount. Installation is completed after the test is passed.

[0043] Segmented membrane bag installation and expanding pellet filling steps: Arrange multiple grouting pipes 1 neatly, and install segmented membrane bags 3 at the membrane bag inlet depth 13. Grouting membrane bags 31 are fitted over all grouting pipes 1, covering the membrane bag inlet area 13, and sealed with clamps. After checking the seal by injecting water through the grouting pipes 1, expandable pellets 32 are filled through the reserved opening, and the opening is sealed after filling.

[0044] The grouting pipe lowering procedure is as follows: lower the pipes in order from deepest to shallowest. The deepest grouting pipe 1 passes through the through holes 22 of all the segmented caps 2 in sequence, and after fixing the segmented caps 2 in their corresponding positions, it is lowered to the bottom of the hole; then lower the next deepest section, and so on. During the lowering process, keep all grouting pipes 1 parallel, each segmented cap 2 at the boundary depth, and each grouting port 14 at the bottom of the corresponding grouting section.

[0045] Grouting pump connection and low-pressure water injection steps: Connect the grout inlet end of each grouting pipe 1 to the multi-channel grouting pump. Start the grouting pump and inject tap water at low pressure, maintaining the set time. Water enters the segmented membrane bag 3 through the membrane bag inlet 13. The expanding granular balls 32 absorb water and expand, causing the grouting membrane bag 31 to tighten the hole wall. Because the pressure is below the opening threshold, the pressure valve 4 remains closed, and water will not enter the downstream. After expansion is complete, the water injection pressure will briefly rise and then stabilize.

[0046] The irreversible opening procedure of the pressure valve is as follows: Continue to increase the water injection pressure to over 1.2 MPa. The valve core of pressure valve 4 opens against the resistance of spring 45, the sealing gasket 44 separates, and the flow channel is connected. At the same time, the one-way locking structure 47 locks the valve core in the open position, and pressure valve 4 remains permanently open, causing the pressure gauge to show a brief drop.

[0047] Switching the grouting procedure: Switch the grouting pump suction pipe from the water tank to the grout mixing tank and inject cement grout. The grout passes through pressure valve 4 and is injected into the corresponding stratum through grouting port 14. Since the segmented membrane bag 3 is reliably sealed, there will be no cross-contamination of grout between segments. Grouting is stopped when the grouting pressure reaches the design pressure and remains stable for more than 10 minutes, and the grouting volume of each pipe meets the design requirements. Grouting pipe 1 is left in the stratum, forming a micro-pile group with the stone body to reinforce the stratum.

[0048] This embodiment solves the problems in existing technologies, such as difficulty in matching the solidification rhythm of sealing materials, easy shrinkage and grout leakage of the membrane bag, repeated opening and closing of the pressure valve generating grout pulses, and grout waste, by organically combining a two-step process of water first and grout later, a passive expansion membrane bag pre-loaded with expansion granular balls 32, and an irreversible pressure valve 4 for mechanical locking. The device and method of this embodiment for segmented grouting construction have the advantages of reliable sealing, good anti-grout leakage effect, stable grouting flow and pressure, high construction efficiency, and low operating cost. It is particularly suitable for underground engineering projects such as tunnels, mines, and deep foundation pits in water-rich and soft strata.

[0049] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A multi-pipe synchronous grouting device with segmented sealing capability, characterized in that, This includes multiple grouting pipes, multiple segmented caps, multiple segmented membrane bags, and multiple pressure valves; The multiple segmented caps are arranged at intervals along the length of the grouting pipe according to the preset grouting segment distance; Each grouting pipe includes an inlet section and an outlet section. The inlet section has a membrane bag inlet, and the outlet section has a grouting port. The membrane bag inlet and the grouting port of each grouting pipe are spaced apart according to the preset grouting section distance. Each segmented membrane bag is installed outside multiple grouting pipes at the boundary between two adjacent grouting sections, and wraps the membrane bag inlet on the grouting pipe at that grouting section; Each pressure valve is installed inside the grouting pipe and located within the pipe section covered by the segmented membrane bag. The pressure valve is configured to close when the liquid pressure in the grouting pipe where the pressure valve is located is less than a set threshold, and to open when the liquid pressure in the grouting pipe where the pressure valve is located exceeds the set threshold, and to remain in an irreversible open state.

2. The multi-pipe synchronous grouting device with segmented sealing capability as described in claim 1, characterized in that, The multiple grouting pipes are arranged parallel to each other along their length. Each segmented cap has a number of through holes equal to the number of grouting pipes. Each grouting pipe passes through the corresponding through hole of its segmented cap and is sealed to the segmented cap.

3. The multi-pipe synchronous grouting device with segmented sealing capability as described in claim 2, characterized in that, The segmented cap includes a cap body, which is configured as a disc-shaped structure. The diameter of the cap body is smaller than the diameter of the required grouting hole. The cap body has multiple through holes running through it along the axial direction. The multiple through holes are evenly distributed on the cap body in a centrally symmetrical manner.

4. The multi-pipe synchronous grouting device with segmented sealing capability as described in claim 1, characterized in that, The segmented membrane bag includes a grouting membrane bag, which covers the inlet of the grouting pipe at the grouting section. The inside of the grouting membrane bag is connected to the inside of the grouting pipe through the inlet. The contact points between the grouting membrane bag and multiple grouting pipes are sealed.

5. A multi-pipe synchronous grouting device with segmented sealing capability as described in claim 4, characterized in that, The grouting membrane bag is filled with expanding granular balls, which are made of high-molecular water-absorbing material particles that increase in volume when exposed to water. The outer diameter of the grouting membrane bag after expansion is larger than the diameter of the required grouting hole.

6. A multi-pipe synchronous grouting device with segmented sealing capability as described in claim 1, characterized in that, The pressure valve includes a pressure valve inlet and a pressure valve outlet. The pressure valve inlet is connected to the inlet section of the pipe body, and the pressure valve outlet is connected to the outlet section of the pipe body. A valve core is provided in the middle of the pressure valve inlet and the pressure valve outlet. The valve core is configured such that: when the liquid pressure in the grouting pipe is less than a set threshold, the valve core is closed, and the channel between the pressure valve inlet and the pressure valve outlet is closed; when the liquid pressure in the grouting pipe is greater than the set threshold, the valve core is opened and remains in an irreversible open state, and the channel between the pressure valve inlet and the pressure valve outlet is opened.

7. A multi-pipe synchronous grouting device with segmented sealing capability as described in claim 6, characterized in that, The valve core includes a valve core seat, and there are two valve core seats, which are symmetrically installed on the inner wall of the grouting pipe. The two valve core seats are respectively provided with valve core sleeves at one end facing the axis of the grouting pipe. A one-way locking structure is provided between the valve core sleeves and the valve core seats. A sealing gasket is provided at one end of the two valve core sleeves facing the axis of the grouting pipe, and the two sealing gaskets abut against each other. A spring is provided inside the valve core sleeve. One end of the spring abuts against the valve core seat, and the other end of the spring abuts against the valve core sleeve.

8. A multi-pipe synchronous grouting device with segmented sealing capability as described in claim 7, characterized in that, The one-way locking structure is specifically as follows: The valve core sleeve is provided with a pawl at one end facing the valve core seat. The valve core seat is provided with a groove-shaped structure along the radial direction of the grouting pipe inside. The groove-shaped structure is provided with a rack that engages with the pawl. The pawl and the rack mesh to form a one-way locking structure. This one-way locking structure only allows the valve core sleeve to move in one direction in the opening direction, and reverse movement is locked.

9. A multi-pipe synchronous grouting device with segmented sealing capability as described in claim 6, characterized in that, The pressure valve inlet is provided with a first flow guiding slope, which gradually extends from the pressure valve inlet end towards the sealing gasket. The pressure valve outlet is provided with a second flow guide slope, which gradually extends from the pressure valve outlet end towards the sealing gasket.

10. A multi-pipe synchronous grouting construction method with segmented sealing, employing a multi-pipe synchronous grouting device with segmented sealing as described in any one of claims 1-9, characterized in that, include: Drill grouting holes; Set the opening pressure of the pressure valve in each grouting pipe to a preset threshold. Segmented membrane bags are installed at the inlet of each grouting pipe, and expanded granular balls are filled into the segmented membrane bags; Multiple grouting pipes are passed through the through holes of each section of the cap and lowered into the grouting holes in order from deep to shallow, so that the grouting port of each grouting pipe is located at the depth of the corresponding grouting section. Water is injected into the grouting pipe at a pressure lower than the opening pressure of the pressure valve. The water is maintained so that it enters the segmented membrane bag through the membrane bag inlet. The expanded granules absorb water and expand, causing the segmented membrane bag to tighten the wall of the grouting hole, thus achieving segmented sealing. Increase the water injection pressure to exceed the opening pressure of the pressure valve, causing the pressure valve to open irreversibly. Switch the injection medium from water to grouting material and continue grouting until the design termination standard is met.

Images