Water injection and grouting type spiral anchor foundation and construction method

Abstract

The invention discloses a water injection and grouting type spiral anchor foundation and a construction method, and relates to the technical field of spiral anchor foundations, the water injection and grouting type spiral anchor foundation comprises a spiral anchor, a connector and a plurality of water injection units, the connector comprises a pipe barrel and a connecting pipe, only one opening end of the pipe barrel is in detachable sealing butt joint with a top opening of an anchor rod, and the connecting pipe penetrates through the side wall of the connecting pipe barrel; the inner end is positioned in the pipe barrel, and the outer end is connected with a grouting machine; the water injection units are sequentially connected, movably arranged in the anchor rod and correspond to the grouting hole sets one to one, each water injection unit comprises an inner cylinder tightly attached to the inner side wall of the anchor rod, a plurality of nozzles are arranged on the cylinder wall of the inner cylinder in a penetrating mode, and the nozzles correspond to the grouting holes of the corresponding grouting hole sets one to one. A water channel can be formed around the anchor rod through water injection, then grouting is conducted on the water channel, the grouting range is expanded, the bearing capacity of the spiral anchor foundation is improved, water injection construction can be conducted through a grouting machine, and water injection pressure higher than grouting pressure is generated.

Description

Technical Field

[0001] The invention relates to the technical field of spiral anchor foundations, in particular to a water injection and grouting type spiral anchor foundation and a construction method. Background Art

[0002] The spiral anchor foundation is an anchoring structure that penetrates deep into the soil resistance. It is screwed into the soil layer by mechanically applying a certain torque on the top of the anchor rod. The spiral anchor foundation with post-grouting method is an improved anchoring structure based on the traditional spiral anchor foundation. It adds a grouting system and performs pressure grouting after the anchor body is screwed into the soil, thereby improving the soil properties around the anchor body and enhancing the interface bonding strength between the anchor body and the soil, thereby significantly improving the foundation bearing capacity.

[0003] Patent publication number CN215669471U discloses a grouting-type composite spiral anchor pile foundation, comprising an anchor rod and an anchor plate that rotates helically around the rod and is fixed to the sidewall of the anchor rod. The system also includes a high-pressure grouting pipe disposed within the anchor rod and extending to the outside of the rod, with a high-pressure grouting hole at the end. This design enhances the bearing capacity of the spiral anchor while reducing its variability and reducing the amount of steel used.

[0004] Patent publication number CN221878155U discloses a spiral anchor foundation comprising an anchor rod, a cap, and a high-pressure grouting pipe. The anchor rod is connected to the cap, with an anchor head provided at the end of the anchor rod away from the cap. An anchor plate is fixedly connected to the outer peripheral wall of the anchor rod. The anchor rod has a hollow passageway within it, within which the high-pressure grouting pipe is disposed. Grouting holes are provided on the outer wall of the anchor rod. The output end of the high-pressure grouting pipe is connected to the grouting hole, and the input end of the high-pressure grouting pipe is provided with a connector that can be connected to the grouting pipe of a grouting machine. This design can improve the pullout resistance and load-bearing capacity of the spiral anchor foundation, thereby enhancing the operational safety of power transmission lines.

[0005] In the prior art, such as the above-mentioned patent, the termination condition for grouting of the spiral anchor foundation is that the grouting volume reaches the design value or grouting is observed on the ground. Since the anchor plate of the spiral anchor will disturb the soil around the anchor rod during the subsequent grouting operation, the cement slurry injected into the ground through the anchor rod will diffuse a certain distance around the anchor rod, and will usually rise to the ground along the soil near the anchor rod. Therefore, the diffusion range of the underground cement slurry is limited, thereby limiting the bearing capacity of the spiral anchor foundation, especially in geological conditions such as fine sand and sandy soil. Summary of the Invention

[0006] The purpose of the present invention is to provide a water injection and grouting type spiral anchor foundation and a construction method to solve the problem in the above-mentioned prior art that the diffusion range of the cement slurry injected into the ground is limited, which limits the bearing capacity of the spiral anchor foundation.

[0007] In order to achieve the above-mentioned objectives, the present invention provides the following technical solutions: a water-injection and grouting spiral anchor foundation, comprising a hollow anchor rod and at least one anchor plate and a plurality of grouting hole groups arranged in the middle and lower sections of the anchor rod, and also comprising: a connecting head, which comprises a tube and a connecting pipe, the only open end of the tube being detachably sealed and docked with the top opening of the anchor rod, the connecting pipe passing through the side wall of the connecting tube, the inner end of which is located inside the tube, and the outer end is used to connect a grouting machine; a plurality of water injection units connected in sequence, which are movably arranged inside the anchor rod and correspond one-to-one to each group of grouting hole groups, each water injection unit comprising an inner cylinder tightly fitted with the inner side wall of the anchor rod, a plurality of nozzles being arranged through the cylinder wall of the inner cylinder, each nozzle corresponding one-to-one to each grouting hole of the corresponding grouting hole group, and each water injection unit has a water injection station for aligning its nozzles with the corresponding grouting holes during the process of moving along the axial direction of the anchor rod.

[0008] Furthermore, a first flange is provided on the top of the anchor rod, and a second flange connected and matched with the first flange is provided at the open end of the tube.

[0009] Furthermore, the inner cylinder of the water injection unit includes a hard tube and a rubber sleeve covering the outer wall of the hard tube, and the nozzle penetrates both the hard tube and the rubber sleeve.

[0010] Furthermore, the inner tubes of the water injection units are connected by a connecting rod, and a pull rod is axially sealed and slidably connected to the tube, and the bottom of the pull rod is connected to the water injection unit located at the top.

[0011] Furthermore, both ends of the inner cylinder are provided with card slots, and the bottom of the pull rod and both ends of the connecting rod are provided with card heads that engage with the card slots.

[0012] Furthermore, each of the water injection units has a pressurizing station for closing the corresponding grouting hole group in the process of moving along the axial direction of the anchor rod. When any part of the water injection units is at the water injection station, the other part of the water injection units is at the pressurizing station.

[0013] Furthermore, the inner end of the connecting pipe is connected to an inner pipe, which is coaxial with the anchor rod and extends into the anchor rod, and a cavity is formed between the outer wall of the inner pipe and the inner wall of the anchor rod; each of the water injection units also has a grouting station located in the cavity during the axial movement of the anchor rod, and when each water injection unit is at the grouting station, the water injection unit located at the bottom is sealed and fitted with the outer wall of the inner pipe through the sealing ring at its bottom.

[0014] Furthermore, a limiting portion is fixedly provided on the pull rod, and an exhaust groove penetrating the limiting portion is provided on the side of the pull rod. When each water injection unit is located at the grouting station, the limiting portion abuts against the top of the tube, and the exhaust groove penetrates the top of the tube to connect the inside and outside of the tube.

[0015] Furthermore, the sealing ring includes a hard ring and a rubber ring embedded on the inner wall of the hard ring.

[0016] The present invention also provides a construction method for a water injection and grouting spiral anchor foundation, comprising the following steps: S1, connecting the top of the anchor rod to a spiral anchor drill, screwing the anchor rod into a predetermined depth underground, and then removing the spiral anchor drill from the anchor rod; S2, installing a connector equipped with multiple water injection units on the anchor rod, inserting each water injection unit into the interior of the anchor rod, and sealingly docking the open end of the tube with the top of the anchor rod, and connecting the outer end of the connecting pipe to the output pipe of the grouting machine; S3, adjusting the water injection unit to a water injection station, and the grouting machine pumps water into the interior of the anchor rod through the connecting pipe, and the water line ejected from the nozzle passes through the grouting hole to flush the soil around the anchor rod into a water channel extending to the distance; S4, adjusting the water injection unit to be separated from the water injection station and leaking out each grouting hole, and the grouting machine pumps cement slurry into the interior of the anchor rod through the connecting pipe, and the cement slurry is injected into the water channel through the grouting hole. When the cement slurry breaks through the water channel and rises to the ground, the grouting is terminated, the connector is removed, and each water injection unit is taken out; S5, and the construction is completed after 24 hours of maintenance.

[0017] Compared with the prior art, the present invention provides a water injection and grouting type spiral anchor foundation, (1) the design position of the water injection unit is adjustable, the water injection unit located at the water injection station first sprays a high-pressure water line to the soil around the anchor rod through the grouting hole, thereby flushing a long water channel far away from the anchor rod, and then the water injection unit is adjusted to be away from the water injection station. When grouting is subsequently performed, cement slurry is injected into the water channel through the grouting hole. The grouting pressure can also make the cement slurry in the water channel penetrate around the water channel, thereby greatly increasing the range of cement slurry diffusion around the anchor rod, so that the bearing capacity of the spiral anchor foundation is greatly improved, especially in the geological conditions such as fine sand and sandy soil. (2) Since the aperture of the nozzle is much smaller than the aperture of the grouting hole, and the flow viscosity (resistance) of water is smaller than the flow viscosity of cement slurry, the grouting machine used for grouting can be shared during water injection. When the power of the grouting machine is the same, the pressure of the water line injected into the soil is much greater than the pressure of the injected cement slurry, so that a longer water channel can be flushed without the need to provide an additional higher-power pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly describe the embodiments of the present application or the technical solutions in the prior art, a brief introduction to the drawings required for use in the embodiments is given below.

[0019] Figure 1 A schematic diagram of the structure during water injection provided in the embodiment; Figure 2 A top view of the structure during water injection provided in the embodiment; Figure 3 for Figure 2 Structural cross-section view along line AA; Figure 4 A cross-sectional view of the structure during pressurized water injection provided in the embodiment; Figure 5 A schematic diagram of the structure during grouting provided in the embodiment; Figure 6 A cross-sectional view of the structure during water injection provided in the embodiment; Figure 7 A schematic structural diagram of a connector provided in an embodiment; Figure 8 A schematic structural diagram of a plurality of sequentially connected water injection units provided in an embodiment; Figure 9 A schematic diagram of the connection structure between the water injection unit and the connecting rod provided in the embodiment; Figure 10 A schematic diagram of the connection structure between the water injection unit and the sealing ring provided in the embodiment; Figure 11 A cross-sectional view of the connection structure between the water injection unit and the sealing ring provided in the embodiment.

[0020] Description of reference numerals: 1. Screw anchor; 11. Anchor rod; 12. Anchor plate; 13. Grouting hole; 14. First flange; 2. Connector; 21. Pipe; 22. End seal; 23. Second flange; 24. Connecting pipe; 25. Inner pipe; 3. Water injection unit; 31. Inner tube; 311. Hard pipe; 312. Rubber sleeve; 32. Nozzle; 33. Slot; 34. Connecting rod; 35. Pull rod; 36. Limiting part; 37. Exhaust groove; 38. Pull handle; 4. Sealing ring; 41. Hard ring; 42. Rubber ring. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0022] See also Figures 1-11 An embodiment of the present invention provides a water injection and grouting type spiral anchor foundation, comprising a spiral anchor 1, a connector 2, and a plurality of water injection units 3. The spiral anchor 1 comprises an anchor rod 11 with a hollow interior, a first flange 14 provided on the top of the anchor rod 11, at least one anchor plate 12 and a plurality of grouting hole groups provided in the middle and lower sections of the anchor rod 11. In this embodiment, the number of anchor plates 12 is three, the grouting hole groups are arranged equidistantly along the axial direction of the anchor rod 11 into four groups, and each group has four grouting holes 13 equidistantly arranged along the circumference of the anchor rod 11 along the axial direction of the anchor rod 11. The number of water injection units 3 is set to four.

[0023] The connector 2 is used to connect the grouting machine and the screw anchor 1 to perform water injection and grouting operations, and mainly includes a tube 21 and a connecting pipe 24. Figure 7The top seal of the tube 21 is screwed or integrally formed with an end seal 22, so the tube 21 has only one open end at the bottom, and a second flange 23 is welded to the open end. The tube 21 is connected to the first flange 14 of the anchor rod 11 through the second flange 23. A sealing gasket is provided between the first flange 14 and the second flange 23, thereby realizing a detachable sealed connection between the open end of the tube 21 and the top of the anchor rod 11, so that the interior of the tube 21 is connected to the inner cavity of the anchor rod 11. The connecting pipe 24 is in the shape of a curved pipe and passes through the side wall of the tube 21. The connecting pipe 24 is fixedly connected to the tube 21. The inner end of the connecting pipe 24 is located inside the tube 21, and the outer end of the connecting pipe 24 is connected to the slurry delivery pipeline outlet of the grouting machine.

[0024] Each water injection unit 3 is connected in sequence through a connecting rod 34 and then movably arranged inside the anchor rod 11. Figure 8 , and can move axially along the anchor rod 11. Each water injection unit 3 corresponds to each group of grouting holes, that is, one water injection unit 3 corresponds to one group of grouting holes. Each water injection unit 3 includes an inner tube 31 that fits tightly with the inner wall of the anchor rod 11. A plurality of nozzles 32 are provided on the tube wall of the inner tube 31. Each nozzle 32 corresponds to each grouting hole 13 of the corresponding grouting hole group, that is, one nozzle 32 corresponds to one grouting hole 13. The aperture of the nozzle 32 is smaller than the aperture of the grouting hole 13.

[0025] Each water injection unit 3 has a water injection station and a pressurizing station during the process of moving along the axial direction of the anchor rod 11. When the water injection unit 3 is at the water injection station, its nozzles 32 are aligned with the corresponding grouting holes 13. Since the inner tube 31 fits tightly against the inner wall of the anchor rod 11, it can prevent the water in the anchor rod 11 from flowing out directly from the grouting hole 13 without passing through the nozzle 32. The inner tube 31 specifically includes a hard tube 311 and a rubber sleeve 312 covering the outer wall of the hard tube 311. The nozzle 32 passes through the hard tube 311 and the rubber sleeve 312 at the same time. The hard tube 311 is made of alloy or hard plastic material, and the rubber sleeve 312 can achieve the effect of sealing the grouting hole 13. After the water injection unit 3 leaves the water injection station, its nozzles 32 will no longer be aligned with the corresponding grouting holes 13.

[0026] The water injection unit 3 located at the water injection station first sprays high-pressure water lines on the soil around the anchor rod 11 through the grouting hole 13, thereby flushing a long water channel far away from the anchor rod 11, and then adjusts the water injection unit 3 to be away from the water injection station. During subsequent grouting, cement slurry is injected into the water channel through the grouting hole 13. The grouting pressure can also make the cement slurry in the water channel penetrate to the surrounding area of ​​the water channel, thereby greatly increasing the range of cement slurry diffusion around the anchor rod 11, so that the bearing capacity of the spiral anchor foundation can be greatly improved, especially in the geological conditions such as fine sand and sandy soil.

[0027] Since the aperture of the nozzle 32 is much smaller than the aperture of the grouting hole 13, and although water and cement slurry are both low-viscosity fluids, the flow viscosity (resistance) of water is smaller than the flow viscosity of cement slurry, the grouting machine used for grouting can be used in common during water injection. When the power of the grouting machine is the same, the pressure of the water line injected into the soil is much greater than the pressure of the cement slurry injected, so that a longer waterway can be flushed out without the need for an additional higher-power pump.

[0028] In addition, the inner cylinders 31 of each water injection unit 3 are connected by a connecting rod 34. A pull rod 35 is axially and slidably connected to the tube 21 in a sealed manner. The top of the pull rod 35 is located outside the tube 21, and the bottom of the pull rod 35 is connected to the inner cylinder 31 of the topmost water injection unit 3. A clamping groove 33 is provided at each end of the inner cylinder 31. The clamping groove 33 is shaped like a large inner groove and a small outer groove. The bottom of the pull rod 35 and the ends of the connecting rod 34 are respectively provided with a clamping head that engages with the clamping groove 33. The clamping head has a large head and a small neck, which can facilitate the assembly and disassembly of the pull rod 35 and the inner cylinder 31, and the connecting rod 34 and the inner cylinder 31.

[0029] In the embodiment provided by the present invention, the length of the connecting rod 34 between the second inner cylinder 31 and the third inner cylinder 31 is shorter than the other connecting rods 34. Therefore, when the two lower water injection units 3 are located at the water injection station, the nozzles 32 of the two upper water injection units 3 are misaligned with the corresponding grouting holes 13, and the grouting holes 13 are completely closed by the inner cylinder 31. At this time, the two upper water injection units 3 are located at the boosting station. Of course, it can also be designed that one or three of the water injection units 3 are at the water injection station, and the remaining water injection units 3 are at the boosting station. In other words, a part of the water injection units 3 are at the water injection station, and the other part of the water injection units 3 are at the boosting station, such as Figure 3-Figure 4 Therefore, when injecting water, by adjusting the water injection units 3 to alternately be in the water injection position through the pull handle 38 and the pull rod 35, the pressure of the water line sprayed by the nozzle 32 of the water injection unit 3 currently located at the water injection position can be further increased, thereby flushing out a longer waterway, and the cement slurry can spread more widely along the waterway during subsequent grouting.

[0030] In another embodiment provided by the present invention, the inner end of the connecting tube 24 is connected to an inner tube 25, which is fixedly connected to the anchor rod 11 via the connecting tube 24, so that the inner tube 25 is fixed relative to the anchor rod 11. The inner tube 25 is located inside the anchor rod 11 and is coaxially arranged with the anchor rod 11. The outer wall of the inner tube 25 and the inner wall of the anchor rod 11 form a cavity. During the axial movement of each water injection unit 3 along the anchor rod 11, it can also move into the cavity between the inner tube 25 and the anchor rod 11. The position of the water injection unit 3 at this time is called a grouting station. When all the water injection units 3 are located at the grouting station, the water injection unit 3 located at the bottom is sealed and fitted with the outer wall of the inner tube 25 through the sealing ring 4 at its bottom, so that each water injection unit 3 can be separated from the middle and lower sections of the inner cavity of the anchor rod 11. During the grouting operation, cement slurry is injected into the middle and lower sections of the inner cavity of the anchor rod 11 through the inner tube 25, and the cement slurry is directly poured into the waterway from each grouting hole 13. Under the obstruction of the sealing ring 4, the cement slurry cannot enter the clamping cavity above the sealing ring 4, and the cement slurry will not contact the water injection unit 3 and the tube 21, thereby protecting the cleanliness of the water injection unit 3 and the tube 21, reducing the wear of the rubber sleeve 312, and especially preventing the nozzle 32 from being blocked.

[0031] More specifically, a handle 38 is provided on the top of the pull rod 35, a limit portion 36 is fixedly provided on the pull rod 35, and an exhaust groove 37 is provided on the side of the pull rod 35 to pass through the limit portion 36. When each water injection unit 3 is located at the grouting station, as shown in FIG. Figure 5-Figure 6 The limiting portion 36 abuts against the top of the tube 21 to provide feedback that all the water injection units 3 have entered the clamping cavity and moved up to their proper positions; at this time, the exhaust groove 37 passes through the top of the tube 21, connecting the inside and outside of the tube 21, releasing the pressure in the clamping cavity and the tube 21. This pressure mainly comes from the compression of the space in the clamping cavity when the sealing ring 4 is sleeved on the inner tube 25 after each grouting unit enters the clamping cavity. The sealing ring 4 is installed to the bottom of the inner tube 25 through two bolt pairs. The nut of the bolt pair is stuck in the card slot 33, and the bolt passes through the through hole on the sealing ring 4 and is screwed to the nut. The specific structure of the sealing ring 4 includes a hard ring 41 and a rubber ring 42 embedded in the inner wall of the hard ring 41. The hard ring 41 is made of alloy or hard plastic material, and the rubber ring 42 can improve the sealing effect between the hard ring 41 and the inner tube 25.

[0032] The present invention also provides a construction method for a water injection and grouting type spiral anchor foundation, which mainly includes the following steps: connecting the top of the anchor rod 11 with a spiral anchor 1 drilling rig, screwing the spiral anchor 1 into a predetermined depth underground, and then removing the spiral anchor 1 drilling rig from the anchor rod 11; installing a connector 2 equipped with multiple water injection units 3 on the anchor rod 11, inserting each water injection unit 3 into the inner cavity of the anchor rod 11, and sealingly docking the open end of the tube 21 with the top opening of the anchor rod 11, tightening the bolt pair between the first flange 14 and the second flange 23, and then connecting the outer end of the connecting pipe 24 to the output pipe of the grouting machine; adjusting the water injection unit 3 to the water injection position through the pull rod 35 (each water injection unit 3 can be alternately in the water injection position), connecting the input pipe of the grouting machine to a water source, and the grouting machine pumping water into the anchor rod 11 through the connecting pipe 24. The water line ejected by the nozzle 32 passes through the grouting hole 13 to flush the soil around the anchor rod 11 out to extend to a distance The extended water channel is then stopped and water injection is waited for 20-30 minutes to allow the anchor rod 11 and the water in the water channel to penetrate into the soil; the water injection unit 3 is moved to the grouting station in the clamping cavity by lifting the pull rod 35, and the grouting holes 13 are leaked. The input pipe of the grouting machine is connected to the cement slurry, and the grouting machine pumps PO42.5 cement slurry (water-cement ratio is 0.5) into the middle and lower inner cavity of the anchor rod 11 through the connecting pipe 24 and the inner pipe 25. The cement slurry is poured into the water channel through the grouting holes 13. When the cement slurry breaks through the water channel and penetrates around the water channel, the grouting is terminated until the cement slurry rises to the ground or the grouting volume reaches the designed value; the connector 2 is removed and the water injection units 3 are taken out, the input pipe of the grouting machine is connected to the water source again and the pump of the grouting machine is started. The input pipe, pump, output pipe, connecting pipe 24 and inner pipe 25 are thoroughly flushed, and the sealing ring 4 and the bottom of the inner pipe 25 are flushed; the spiral anchor foundation is cured for 24 hours and the construction is completed.

[0033] The above description of certain exemplary embodiments of the present invention should not be construed as limiting the scope of protection of the claims of the present invention. For those skilled in the art, the described embodiments may be modified in other different ways without departing from the spirit and scope of the present invention.

Claims

1. A water injection and grouting type spiral anchor foundation, comprising a hollow anchor rod and at least one anchor plate and a plurality of grouting hole groups arranged in the middle and lower sections of the anchor rod, characterized in that: Also includes: The connector includes a tube and a connecting pipe. The only open end of the tube is detachably sealed with the top opening of the anchor rod. The connecting pipe passes through the side wall of the connecting tube, with its inner end located inside the tube and its outer end used for connecting to a grouting machine. A plurality of water injection units connected in sequence are movably arranged inside the anchor rod and correspond one-to-one to each group of grouting holes. Each water injection unit includes an inner cylinder tightly fitted with the inner wall of the anchor rod. A plurality of nozzles are provided through the wall of the inner cylinder. Each nozzle corresponds one-to-one to each grouting hole of the corresponding grouting hole group. During the process of each water injection unit moving along the axial direction of the anchor rod, it has a water injection station for aligning its nozzles with the corresponding grouting holes.

2. The water injection grouting type spiral anchor foundation according to claim 1, characterized in that: A first flange is provided on the top of the anchor rod, and a second flange connected and matched with the first flange is provided at the open end of the tube.

3. The water injection grouting type spiral anchor foundation according to claim 1, characterized in that: The inner cylinder of the water injection unit includes a hard pipe and a rubber sleeve wrapped on the outer wall of the hard pipe, and the nozzle penetrates the hard pipe and the rubber sleeve at the same time.

4. The water injection grouting type spiral anchor foundation according to claim 1, characterized in that: The inner cylinders of the water injection units are connected by connecting rods. A pull rod is connected to the tube in an axially sealed sliding manner, and the bottom of the pull rod is connected to the water injection unit located at the top.

5. The water injection grouting type spiral anchor foundation according to claim 4, characterized in that: Both ends of the inner cylinder are respectively provided with clamping grooves, and the bottom of the pull rod and both ends of the connecting rod are respectively provided with clamping heads that are clamped and matched with the clamping grooves.

6. The water injection grouting type spiral anchor foundation according to claim 1 or 4, characterized in that: During the process of the water injection units moving along the axial direction of the anchor rod, there is also a pressurizing station for closing the corresponding grouting hole group in the inner cylinder. When any part of the water injection units is at the water injection station, the other part of the water injection units is at the pressurizing station.

7. The water injection grouting type spiral anchor foundation according to claim 4, characterized in that: The inner end of the connecting tube is connected to the inner tube, which is coaxial with the anchor rod and extends into the anchor rod, and a cavity is formed between the outer wall of the inner tube and the inner wall of the anchor rod; During the axial movement of each water injection unit along the anchor rod, there is also a grouting station located in the clamping cavity. When each water injection unit is located at the grouting station, the water injection unit located at the bottom is sealed and sleeved with the outer wall of the inner tube through the sealing ring at its bottom.

8. The water injection grouting type spiral anchor foundation according to claim 7, characterized in that: A limiting portion is fixedly provided on the pull rod, and an exhaust groove penetrating the limiting portion is provided on the side of the pull rod. When each water injection unit is located at the grouting station, the limiting portion abuts against the top of the tube, and the exhaust groove penetrates the top of the tube to connect the inside and outside of the tube.

9. The water injection grouting type spiral anchor foundation according to claim 7, characterized in that: The sealing ring comprises a hard ring and a rubber ring embedded on the inner side wall of the hard ring.

10. A construction method, based on the water injection grouting type spiral anchor foundation according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Connect the top of the anchor rod to the screw anchor drill, screw the anchor rod into the ground to a predetermined depth, and then remove the screw anchor drill from the anchor rod; S2. Install a connector equipped with multiple water injection units onto the anchor rod, insert each water injection unit into the interior of the anchor rod, and seal the open end of the tube with the top of the anchor rod. Connect the outer end of the connecting tube to the output pipe of the grouting machine. S3. Adjust the water injection unit to the water injection position. The grouting machine pumps water into the anchor rod through the connecting pipe. The water line ejected from the nozzle passes through the grouting hole and washes the soil around the anchor rod to form a water channel extending to the distance. S4. Adjust the water injection unit to be away from the water injection station and leak out the grouting holes. The grouting machine pumps cement slurry into the anchor bolt through the connecting pipe. The cement slurry is injected into the water channel through the grouting hole. When the cement slurry breaks through the water channel and rises to the ground, the grouting is terminated. The connector is removed and the water injection unit is taken out. S5. Construction is completed after 24 hours of maintenance.

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