A forward quantitative variable pressure grouting device and method

Abstract

The present application relates to the technical field of underground engineering grouting reinforcement, and discloses a forward quantitative variable-pressure grouting device and method, the grouting device comprising a steel pipe, a plurality of groups of combined units being wrapped around the side of the steel pipe along the axial direction, each group of combined units comprising a mold belt and a sleeve material arranged in sequence, a quincunx hole being formed in the side wall of the steel pipe and arranged in position corresponding to the combined units; one end of a tension spring is connected to the first end of the steel pipe, and the other end of the tension spring is connected to an isolation plate; the first end of the steel pipe is used for connecting a grouting pipe, and the steel pipe is segmentedly grouted through the grouting pipe to change the grouting pressure by tension deformation of the tension spring; the deformation of the tension spring can be accurately controlled, and the grouting pressure change in the process from shallow to deep can be controlled, which conforms to the change law of lateral stress in the stratum. In the forward sectional grouting, the initial pressure of the subsequent section is the end pressure of the previous section, and it is not necessary to start from '0 pressure', so that the grouting pressure is continuously improved in the whole grouting process, and the construction continuity is strong.

Description

Technical Field

[0001] This invention relates to the field of underground engineering grouting reinforcement technology, and in particular to a forward-moving quantitative variable pressure grouting device and method. Background Technology

[0002] In underground engineering construction, adverse geological conditions such as fractured surrounding rock and weak soil layers are often encountered. Grouting reinforcement has become a common technical means for reinforcing adverse geological bodies due to its mature construction technology and good reinforcement effect. Compared with full-hole one-time grouting, segmented grouting has more uniform grout diffusion and better reinforcement effect.

[0003] Commonly used segmented grouting methods include forward segmented grouting and backward segmented grouting. Forward segmented grouting involves drilling and grouting the first section, then re-drilling to the second section, followed by grouting. This cycle is repeated until the designed depth is reached. Backward segmented grouting involves drilling to the designed depth, with the grout entering the hole through the drill rod and drill bit, and then using the backward movement of the drill rod to achieve segmented grouting. However, forward segmented grouting requires inserting a grouting pipe for each segment, resulting in a complex operation, long operation time, and high material consumption. Backward grouting lacks effective isolation measures between sections, leading to poor controllability of grout diffusion and weaker reinforcement effect in the treated area.

[0004] (1) Chinese Patent ZL 201410180539.X discloses a forward segmented grouting device suitable for grouting model experiments. Its pressure-bearing expansion device is connected through a grouting pipe, and a grout stopper is placed in the cavity of the pressure-bearing expansion device. At least one overflow port is provided on the grouting pipe in front of each pressure-bearing expansion device. The grout stopper is tightly attached to the cavity wall in the cavity of the pressure-bearing expansion device. The inner diameter of the pressure-bearing expansion device is larger than the inner diameter of the grouting pipe.

[0005] (2) Chinese Patent ZL 201910600577.9 discloses a forward drilling and grouting integrated device and its usage method, including a drill rod, an inner tube inside the drill rod, the inner tube being used to inject drilling fluid during drilling or grouting during grouting, the inner tube extending to the outside of the drill rod and communicating with multiple outer tubes; the drill rod includes multiple drill rod sections, one of which is provided with an expandable grout-stopping water bladder on its outer side, the expandable grout-stopping water bladder being communicated with a water injection pipe; during drilling, water flows out of the expandable grout-stopping water bladder through the water injection pipe so that the expandable grouting water bladder is tightly attached to the outer wall of the drill rod section; during grouting, water flows into the expandable grout-stopping water bladder through the water injection pipe to seal the hole and stop grouting.

[0006] (3) Chinese Patent ZL 201921620584.7 discloses a segmented forward-moving drill rod rapid grouting device. Each double-tube drill rod is a concentric double-layer tube structure, with an annular channel formed between the outer and inner tubes. The inner tube is hollow. Each double-tube drill rod is used to be axially arranged in segments within the grouting hole, and can be detachably connected and communicated sequentially. The drill bit has a single through hole axially opened, which is connected to the end of the foremost double-tube drill rod. Multiple hydraulic bladder infusion tubes, each of which is a tube body with open ends, are arranged parallel to and closely fitted with the double-tube drill rods. The grout-stopping hydraulic bladder is a hollow elastic bladder that covers the outer wall of the front section of the foremost double-tube drill rod and is connected to the foremost hydraulic bladder infusion tube.

[0007] A comprehensive analysis of the above technical solutions reveals the following shortcomings:

[0008] 1. The working pressure of the pressure-bearing expansion device or the expansion-type grout stopper is fixed, which makes it impossible to control and adjust the grouting pressure and does not conform to the variation law of formation stress with depth.

[0009] 2. During the forward grouting process, the grouting pressure of each section starts from "0 pressure" (initial pressure), resulting in poor continuity of the entire borehole grouting construction.

[0010] 3. The excessive number of various grouting pipe fittings interferes with grout diffusion, makes operation cumbersome, and wastes engineering materials.

[0011] 4. The expansion-type grout stop plug is set on the outside of the drill pipe and advances with the drill. It is very easy to wear and fail during the process, which will affect the construction progress. Summary of the Invention

[0012] To address the shortcomings of existing technologies, the present invention aims to provide a forward-moving quantitative variable pressure grouting device and method. The grouting pressure can be precisely and quantitatively controlled, and the grouting pressure of each forward-moving section can be continuously increased, with each section alternately supported and grouted. No re-drilling is required, resulting in low engineering costs.

[0013] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0014] In a first aspect, a forward-moving quantitative variable pressure grouting device includes a steel pipe, with multiple sets of combined units wrapped around the periphery of the steel pipe in the axial direction. Each set of combined units consists of a mold strip and a shell material arranged sequentially. The side wall of the steel pipe has staggered holes, which are arranged corresponding to the positions of the combined units. One end of the steel pipe is connected to a tension spring, and the other end of the tension spring is connected to an isolation plate. The first end of the steel pipe is used to connect to a grouting pipe. Grout is injected into the steel pipe in sections through the grouting pipe so that the grouting pressure is changed by the tension deformation of the tension spring.

[0015] As a further implementation, the diameters of different die strips from the first end to the second end of the steel pipe increase sequentially.

[0016] As a further implementation, the mold strips and housing materials of different combination units are staggered.

[0017] As a further implementation, a sealing ring is provided around the periphery of the isolation plate, and the sealing ring is located between the inner wall of the steel pipe and the isolation plate.

[0018] As a further implementation, a limiting ring is provided inside the steel pipe near the second end, and the space between the limiting ring and the second end of the steel pipe is used to place a chemical material package. The isolation plate is provided with needles on the side near the second end of the steel pipe.

[0019] As a further implementation, the limiting ring has a hole, which is corresponding to the needle puncture, so that the isolation plate moves toward the limiting ring and punctures the chemical material package through the needle puncture.

[0020] As a further implementation, the second end of the steel pipe is conical, and a plum blossom hole is also provided on the side wall, while the first end of the steel pipe is provided with a material injection port.

[0021] As a further implementation, the injection port includes a cement slurry injection port and a water glass injection port, and the first end of the steel pipe is also provided with a pressure relief port.

[0022] Secondly, a forward-moving quantitative variable pressure grouting method, employing a forward-moving quantitative variable pressure grouting device as described in any one of claims 1-8, includes the following steps:

[0023] Insert the steel pipe into the drill hole, and calculate the tensile deformation of the tension spring under different forces based on the selected isolation plate area and tension spring stiffness.

[0024] The slurry is injected from the injection port of the steel pipe. Under different injection pressures, the tension spring deforms accordingly, and the slurry flows into the matching mold strip or breaks through the matching shell material.

[0025] As the grouting pressure continues to increase, the tension spring continues to deform, and the isolation plate is pushed towards the limiting ring, allowing the grout to flow into the next section of the mold strip or casing material.

[0026] Repeat the above steps. When the tension spring reaches its maximum tensile deformation, the needles on the isolation plate will pierce the chemical material package and reinforce the second end of the steel pipe.

[0027] As a further implementation method, an inlet valve is installed at the injection port and a pressure relief valve is installed at the pressure relief port, and pressure is released through the pressure relief valve during the grouting process.

[0028] The beneficial effects of the present invention are as follows:

[0029] 1. This invention can precisely and quantitatively control the deformation of the tension spring, thereby accurately controlling the change in grouting pressure from shallow to deep, conforming to the actual variation law of lateral stress in the stratum. In the forward sectional grouting, the initial pressure of the subsequent section is the ending pressure of the previous section, without having to start from "0 pressure", realizing a continuous increase in grouting pressure throughout the grouting process, and ensuring strong construction continuity.

[0030] 2. The isolation plate and sealing ring of this invention make it easy to isolate each section; the different grades of mold strips outside the seamless steel pipe not only have a supporting function but also limit the backflow of slurry; the alternating configuration of mold strips and shell material can significantly improve the reinforcement effect of the formation.

[0031] 3. The grouting device of the present invention is integrally and simply formed. Only one seamless steel pipe needs to be installed in the borehole. There is no need to place other grouting pipelines, which has no impact on the diffusion of grout and makes construction and operation simple.

[0032] 4. This invention consumes less engineering materials, requires no re-drilling, and has low engineering costs. Attached Figure Description

[0033] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0034] Figure 1 This is a schematic diagram of the overall structure of the forward-moving quantitative variable pressure grouting device in an embodiment of the present invention.

[0035] Figure 2 This is a front view of the isolation plate in an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of the limiting ring in an embodiment of the present invention.

[0037] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0038] The components include: 1. Cement slurry pipeline, 2. Water glass pipeline, 3. Mixer, 4. Slurry inlet valve, 5. Pressure relief valve, 6-1. Primary mold belt, 6-2. Secondary mold belt, 6-3. Tertiary mold belt, 7. Shell material, 8. Plum blossom hole, 9. Tension spring, 10. Isolation plate, 11. Needle punch, 12. Sealing ring, 13. Limiting ring, and 14. Chemical material package. Detailed Implementation

[0039] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0040] Example 1

[0041] In a typical embodiment of the present invention, reference is made to Figures 1-3 As shown, a forward-moving quantitative variable pressure grouting device includes a steel pipe, which comprises a cement slurry pipeline 1, a water glass pipeline 2, a mixer 3, a slurry inlet valve 4, a pressure relief valve 5, a mold belt 6: a primary mold belt 6-1, a secondary mold belt 6-2, a tertiary mold belt 6-3, a casing material 7, a perforated hole 8, a tension spring 9, a partition plate 10, a needle-punched part 11, a sealing ring 12, a limiting ring 13, and a chemical material package 14. The specific structure is as follows:

[0042] The steel pipe is a seamless steel pipe, with multiple sets of combined units wrapped around its circumference along the axial direction. Each combined unit includes a mold strip 6 and a shell material 7 arranged sequentially, forming a "mold strip 6 + shell material 7" combined unit. The side wall of the steel pipe has quincunx holes 8, which are positioned corresponding to the "mold strip 6 + shell material 7" combined unit.

[0043] like Figure 1 As shown in the diagram, the right end of the steel pipe is the front end, which is also the drilling end or the first end; the left end of the steel pipe is the rear end, which is also the borehole end or the second end.

[0044] The left end of the steel pipe is used to connect to the grouting pipe. Specifically, in this embodiment, when grouting the borehole, a mixture of cement slurry and water glass is preferred. The first end of the steel pipe is provided with an injection port for connecting to the grouting pipe. The injection port includes a cement slurry injection port and a water glass injection port. The first end of the steel pipe is also provided with a pressure relief port. Therefore, the first end of the steel pipe is provided with a cement slurry pipeline 1 and a water glass pipeline 2. The cement slurry pipeline 1 and the water glass pipeline 2 are connected. The end of the cement slurry pipeline 1 is the cement slurry injection port, and the end of the water glass pipeline 2 is the water glass injection port. Furthermore, a mixer 3 is provided on the pipeline where the cement slurry pipeline 1 and the water glass pipeline 2 connect to the steel pipe. The mixer 3 is used to achieve uniform mixing of cement slurry and water glass.

[0045] A grout inlet valve 4 is provided between the mixer 3 and the first end of the steel pipe, and a pressure relief valve 5 is also provided at the first end of the steel pipe for pressure relief during grouting.

[0046] The first end of the steel pipe is connected to the left end of the tension spring 9, and the right end of the tension spring 9 is connected to the isolation plate 10. The isolation plate 10 is circular, and its outer diameter is matched with the inner diameter of the steel pipe. The isolation plate 10 has grooves on its periphery for installing the sealing ring 12. The sealing ring 12 is located between the inner wall of the steel pipe and the isolation plate 10 to achieve a seal.

[0047] In this embodiment, the tension spring 9 can be designed with different spring material diameters, spring mean diameters, winding ratios, and effective number of turns to obtain different spring stiffnesses, thereby precisely controlling the spring deformation under different tensions.

[0048] Multiple sets of "mold strip + shell material" combination units are wrapped around the circumference of the steel pipe along the axial direction. In this embodiment, there are three sets of "mold strip + shell material" combination units, and the mold strips 6 and shell materials 7 are staggered between different combination units. The diameter of the mold strips 6 in different sets from the first end to the second end of the steel pipe increases sequentially, that is, the diameter of the mold strips 6 in each combination unit varies according to its location, that is, the diameter increases sequentially from shallow to deep position.

[0049] The isolation plate 10 and the sealing ring 12 make it easy to isolate each section; the different grades of mold strips outside the seamless steel pipe not only provide support but also limit the backflow of slurry; the alternating configuration of mold strips and casing material can significantly improve the reinforcement effect of the formation.

[0050] like Figure 1 As shown, the mold strips and housing materials in the three sets of combined units from left to right are staggered and divided into six segments. In each set of combined units, the mold strip 6 is located to the left of the housing material 7. Therefore, the odd-numbered segments are the mold strip 6, and the even-numbered segments (segments 2, 4, and 6) are the housing material 7. The first segment is the primary mold strip 6-1, the third segment is the secondary mold strip 6-2, and the fifth segment is the tertiary mold strip 6-3. The design position of the "mold strip 6 + housing material 7" combined unit matches the total length of the tension spring 9 after deformation.

[0051] A limiting ring 13 is provided inside the steel pipe near the second end. The space between the limiting ring 13 and the second end of the steel pipe is used to place the chemical material package 14. The limiting ring 13 is used to fix the chemical material package and restrict its movement.

[0052] The isolation plate 10 is provided with a needle 11 on the side near the second end of the steel pipe. The limiting ring 13 has an opening, which is set to correspond to the needle 11. This is so that when grouting is performed, the grout pushes the isolation plate 10, the isolation plate 10 pulls the tension spring 9, and the isolation plate 10 moves along the steel pipe towards the limiting ring 13 at the second end inside the steel pipe, puncturing the chemical material package 14 through the needle.

[0053] The second end of the steel pipe is conical, and there are also plum blossom holes on the side wall. When the chemical material package 14 is punctured, the high-strength chemical material flows out from the second end of the steel pipe through the plum blossom holes 8, and the high-strength chemical material reinforces the conical part of the steel pipe.

[0054] After the steel pipe is inserted into the borehole, the first end of the steel pipe is connected through a grouting pipe, and grout is injected into the steel pipe in sections. The grouting pressure is changed by the tension deformation of the tension spring 9. Specifically, during the construction process, the grout flows into the seamless steel pipe from the grout inlet valve 4. Under different grouting pressures, the tension spring 9 deforms accordingly, and the grout flows into the matching mold strip 6 or breaks through the matching casing material 7.

[0055] As the grouting pressure continues to increase, the tension spring 9 continues to deform, and the isolation plate 10 moves forward accordingly, with the grout flowing into the subsequent mold belt 6 or shell material 7; repeating the above steps, when the spring 9 reaches the maximum tensile deformation, the needle 11 on the isolation plate 10 will puncture the chemical package 14, and the high-strength chemical material will reinforce the conical part of the steel pipe.

[0056] The entire grouting device is a simple, integrated design. Only one seamless steel pipe is needed inside the borehole, eliminating the need for other grouting pipelines and having no impact on grout diffusion. The construction and operation are simple.

[0057] This embodiment can precisely and quantitatively control the deformation of the tension spring 9, thereby accurately controlling the change in grouting pressure from shallow to deep, which conforms to the actual change law of lateral stress in the stratum. In the forward sectional grouting, the initial pressure of the subsequent section is the ending pressure of the previous section, without having to start from "0 pressure", realizing the continuous increase of grouting pressure throughout the grouting process and ensuring strong construction continuity.

[0058] Example 2

[0059] A forward-moving quantitative variable pressure grouting method, employing a forward-moving quantitative variable pressure grouting device as described in Example 1, includes the following steps:

[0060] Select the outer diameter, wall thickness, and length of the seamless steel pipe. Select the spring material and diameter, and design the spring mean diameter, winding ratio, and effective number of turns in sequence. Determine the spring stiffness, initial length, and deformation length. Select the diameter and thickness of the isolation plate 10. Design the outer perimeter of the isolation plate 10 as a groove and padded with a sealing ring 12.

[0061] The second section of the steel pipe is fixed to the chemical material package 14 by the limiting ring 13. Then the steel pipe is inserted into the drill hole. Based on the selected isolation plate area and the stiffness of the tension spring 9, the tensile deformation of the tension spring 9 under different forces is calculated.

[0062] A grout inlet valve 4 is installed at the grout inlet, and a pressure relief valve 5 is installed at the pressure relief outlet. Grout is injected from the grout inlet of the steel pipe. During the grouting process, pressure is released through the pressure relief valve 5. Under different grouting pressures, the tension spring 9 deforms accordingly. The grout flows into the matching mold strip 6 or breaks through the matching shell material 7 through the plum blossom hole 8.

[0063] As the grouting pressure continues to increase, the tension spring continues to deform, and the isolation plate is pushed towards the limiting ring, allowing the grout to flow into the next section of the mold strip or casing material.

[0064] Repeat the above steps. When the tension spring reaches its maximum tensile deformation, the needles on the isolation plate will pierce the chemical material package and reinforce the second end of the steel pipe.

[0065] In a preferred construction example:

[0066] (1) Select the seamless steel pipe with an outer diameter of 108mm and a wall thickness of 4mm; the material of the tension spring 9 is oil-quenched and tempered TDC, with a spring wire diameter of 16mm. The design is a winding ratio of 4, a spring middle diameter of 65mm, and a spring coil of 250 coils. The actual stiffness of the spring is 10N / mm and the initial length of the spring is 260mm.

[0067] (2) The isolation plate 10 has a diameter of 100mm and a thickness of 6mm. The outer circumferential groove is 1mm deep and a 2mm sealing ring 12 is provided. A needle 11 is provided on one side of the isolation plate 10 in the forward direction. The tension spring 9 is connected to the steel pipe joint at the end of the steel pipe hole and the isolation plate 10 by high-strength welding.

[0068] (3) Based on the area of ​​the isolation plate 10 (9156mm²) 2 ), with a stiffness of 10 N / mm and an initial length of 260 mm, calculate the tensile deformation of the spring under different applied forces:

[0069] When the tension is 0-2000N (the pressure on the isolation plate 10 is 0-0.22MPa), the tensile deformation of the tension spring 9 is 0-200mm, that is, the total length of the tension spring 9 is 260-460mm.

[0070] When the tensile force is 2000-4000N (the pressure on the isolation plate 10 is 0.22-0.44MPa), the tensile deformation of the tension spring 9 is 200-400mm, that is, the total length of the spring 9 is 460-660mm.

[0071] When the tensile force is 4000~6000N (the pressure on the isolation plate 10 is 0.44~0.66MPa), the tensile deformation of the tension spring 9 is 400~600mm, that is, the total length of the tension spring 9 is 660~860mm.

[0072] When the tensile force is 6000~8000N (the pressure on the isolation plate 10 is 0.66~0.88MPa), the tensile deformation of the tension spring 9 is 600~800mm, that is, the total length of the tension spring 9 is 860~1060mm;

[0073] When the tension is 8000~10000N (the pressure on the isolation plate 10 is 0.88~1.10MPa), the tensile deformation of the tension spring 9 is 800~1000mm, that is, the total length of the spring 9 is 1060~1260mm.

[0074] (4) According to the deformation of the tension spring 9, make a plum blossom hole 8 at the corresponding position on the outer wall of the seamless steel pipe and match the wrapping mold strip 6 (first-level mold strip 6-1 of the first section, second-level mold strip 6-2 of the third section, and third-level mold strip 6-3 of the fifth section) and the shell material 7 (second, fourth and sixth sections).

[0075] For example, in the first section (0-300mm), 8 quincunx holes with a diameter of 4mm are opened in the wall of the 100-200mm steel pipe, and the pipe wall is wrapped with a first-level mold strip 6-1, which has a diameter of 100mm after filling.

[0076] Section 2 (300-500mm): 8 quincunx holes with a diameter of 4mm are opened in the wall of the 350-450mm steel pipe, and the pipe wall is wrapped with a shell material 7.

[0077] Section 3 (500-700mm): 8 quincunx holes with a diameter of 4mm are opened in the wall of the 550-650mm steel pipe. The pipe wall is wrapped with a secondary mold strip 6-2, which has a diameter of 200mm after expansion.

[0078] Section 4 (700-900mm): 8 quincunx holes 8 with a diameter of 4mm are opened in the wall of the 750-850mm steel pipe, and the pipe wall is wrapped with a shell material 7.

[0079] Section 5 (900-1100mm): 8 quincunx holes with a diameter of 4mm are opened in the steel pipe wall of 950-1050mm. The pipe wall is wrapped with a three-stage mold strip 6-3, which has a diameter of 300mm after expansion.

[0080] Section 6 (1100~1300mm) has 8 quincunx holes with a diameter of 4mm in the steel pipe wall of 1150~1250mm, and the pipe wall is wrapped with shell material 7.

[0081] (5) The 7th section of the seamless steel pipe (1300-1500mm) is conical and has 8 quincunx holes 8 on the side wall with a diameter of 4mm, arranged in a quincunx pattern. A chemical material package 14 is placed inside the cone, and then a limiting ring 13 is placed to restrict the movement of the package. A steel pipe joint is provided at the end of the steel pipe opening, with a slurry inlet and a pressure relief port.

[0082] (6) During construction, the two-liquid grout (a mixture of cement grout and water glass) enters the seamless steel pipe through the grout inlet valve 4.

[0083] First, under initial pressureless conditions, the grout fills the first-stage mold strip 6-1 on the first section of the steel pipe; as the grouting pressure increases, the tension spring 9 begins to deform, and when the pressure of the isolation plate 10 is 0-0.22MPa, the grout breaks through the casing material 7 on the second section of the steel pipe and enters the formation.

[0084] As the grouting pressure continues to rise, the tension spring 9 continues to deform. When the pressure of the isolation plate 10 is 0.22 to 0.44 MPa, the grout fills the secondary mold strip 6-2 on the third section of the steel pipe. As the grouting pressure continues to rise, when the pressure of the isolation plate 10 is 0.44 to 0.66 MPa, the grout breaks through the casing material 7 on the fourth section of the steel pipe and enters the formation.

[0085] As the grouting pressure continues to rise, when the pressure of the isolation plate 10 is 0.66 to 0.88 MPa, the grout fills the third-stage formwork 6-3 on the fifth section of the steel pipe; as the grouting pressure continues to rise, when the pressure of the isolation plate 10 is 0.88 to 1.10 MPa, the grout breaks through the casing material 7 on the sixth section of the steel pipe and enters the formation.

[0086] Finally, when the pressure of the isolation plate 10 exceeds 1.10 MPa, the needles 11 on the isolation plate 10 will puncture the chemical material package 14, which includes packages A, B, C, and D. The chemical material enters the formation through the conical sidewall hole 8, and the high-strength chemical material reinforces the end of the steel pipe.

[0087] This embodiment solves the problems of easy wear of traditional expansion grout stop plugs during drilling, fixed working pressure of grout stop plugs, poor continuity of grouting in forward-moving sections, excessive grouting pipelines in the borehole, and high construction costs. Compared with the existing technology, this embodiment has the characteristics of precise quantitative control of grouting pressure, continuous increase of grouting pressure in each forward-moving section, alternating support and grouting in each section, limiting grout backflow to improve reinforcement effect, and no need for re-drilling.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A forward-moving quantitative variable pressure grouting device, characterized in that, The system includes a steel pipe, with multiple sets of combined units wrapped around its circumference along the axial direction. Each set of combined units consists of a mold strip and a shell material arranged sequentially. The side wall of the steel pipe has staggered holes, which are positioned corresponding to the combined units. Inside the steel pipe, one end is connected to a tension spring, and the other end of the tension spring is connected to a partition plate. The first end of the steel pipe is used to connect to a grouting pipe, through which grout is injected into the steel pipe in sections, and the grouting pressure is changed by the tension deformation of the tension spring. As the grouting pressure continues to increase, the tension spring continues to deform, and the isolation plate moves forward accordingly. The design position of the mold strip and the housing material combination unit matches the total length of the tension spring after deformation. The initial pressure of the subsequent section is the ending pressure of the previous section. Tension springs can achieve different spring stiffnesses by designing different spring material diameters, spring mean diameters, winding ratios, and effective number of turns, thereby precisely controlling spring deformation under different tensions; A limiting ring is provided inside the steel pipe near the second end. The second end of the steel pipe is conical. The space between the limiting ring and the second end of the steel pipe is used to place a chemical material package. The isolation plate is provided with a needle on the side near the second end of the steel pipe. The limiting ring has a hole, which is set to correspond to the needle, so that the isolation plate can move toward the limiting ring and puncture the chemical material package through the needle. Under different grouting pressures, the tension springs deform accordingly, and the grout flows into the matching mold strip or breaks through the matching sleeve material. When the spring reaches its maximum tensile deformation, the needle punctures the chemical package and reinforces the conical part of the steel pipe. The steel pipe is a seamless steel pipe, and the diameters of different mold strips from the first end to the second end of the steel pipe increase sequentially. The mold strips and shell materials of different combination units are staggered.

2. The forward-moving quantitative variable pressure grouting device according to claim 1, characterized in that, The isolation plate is provided with a sealing ring around its periphery, and the sealing ring is located between the inner wall of the steel pipe and the isolation plate.

3. The forward-moving quantitative variable pressure grouting device according to claim 1, characterized in that, The second end of the steel pipe is conical, and the side wall is also provided with plum blossom holes. The first end of the steel pipe is provided with a material injection port.

4. The forward-moving quantitative variable pressure grouting device according to claim 3, characterized in that, The injection ports include cement slurry injection ports and water glass injection ports, and the first end of the steel pipe is also provided with a pressure relief port.

5. A forward-moving quantitative variable pressure grouting method, characterized in that, The method of using a forward-moving quantitative variable pressure grouting device as described in any one of claims 1-4 includes the following steps: Insert the steel pipe into the drill hole, and calculate the tensile deformation of the tension spring under different forces based on the selected isolation plate area and tension spring stiffness. The slurry is injected from the injection port of the steel pipe. Under different injection pressures, the tension spring deforms accordingly, and the slurry flows into the matching mold strip or breaks through the matching shell material. As the grouting pressure continues to increase, the tension spring continues to deform, and the isolation plate is pushed towards the limiting ring, allowing the grout to flow into the next section of the mold strip or casing material. Repeat the above steps. When the tension spring reaches its maximum tensile deformation, the needles on the isolation plate will pierce the chemical material package and reinforce the second end of the steel pipe.

6. The method for forward-moving quantitative variable pressure grouting according to claim 5, characterized in that, A grout inlet valve is installed at the grout injection port, and a pressure relief valve is installed at the pressure relief port. Pressure is released through the pressure relief valves during the grouting process.

Images