Bridge pile foundation ring type grouting device and method

Abstract

The application provides a kind of approach bridge pile foundation ring type grouting device, comprising: ring pipe, grouting pipe, stop grouting valve, stop grouting valve includes grouting pipe and pressure pipe, one end of grouting pipe is connected grouting pump through grouting pipe, the other end is closed end, grouting pipe is equipped with grouting outlet in middle part, grouting pipe is respectively sleeved with balloon in both ends, balloon in both ends of grouting pipe is connected in series through pressure pipe, two balloons respectively block both sides of the communication place of one ring pipe and grouting pipe, to make grouting pipe, grouting outlet and all grouting valves of corresponding ring pipe form grouting channel.Ring pipe is connected multiple stop grouting valves, so that multiple stop grouting valves of the same elevation are grouted through ring pipe, not only can realize the design of different grouting pressure, but also can greatly provide grouting efficiency.Grouting valve pressurizes slurry cement slurry into pile side soil layer, and the strength of mud skin around pile is enhanced through slurry, so as to achieve the effect of improving the ultimate bearing capacity of pile foundation and reducing the amount of sinking.

Description

Technical Field

[0001] This invention belongs to the field of bridge pile foundation construction technology, specifically relating to a ring-type grouting device and method for approach bridge pile foundations. Background Technology

[0002] Drilled pile technology is widely used in the field of engineering construction. In the past 20 years, with the rapid development of infrastructure in my country, the requirements for foundation bearing capacity have become increasingly higher, and the requirements for pile bearing capacity have also continued to increase. Grouting technology can significantly improve the bearing capacity of the pile body and has been widely used. In the existing technology, the grouting pipe is tied to the steel cage, and grouting is carried out through the grouting port on the side of the grouting pipe. When the pile body concrete is poured, the grouting pressure is consistent after each grouting, and it is impossible to adjust the grouting pressure for different elevation positions.

[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a ring grouting device and method for approach bridge pile foundations.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A ring-type grouting device for approach bridge pile foundations includes:

[0007] A ring pipe is concentrically arranged inside the reinforcing cage, and multiple grout outlet valves are distributed on the ring pipe, with the grout outlet valves extending radially out of the outer circumference of the reinforcing cage.

[0008] Grouting pipe, which extends along the axial direction of the reinforcing cage and is connected in series with multiple ring pipes;

[0009] A grout stop valve is correspondingly disposed inside the grouting pipe and is slidably assembled along the axial direction of the grouting pipe.

[0010] The grout stop valve includes a grouting pipe and a pressurizing pipe. One end of the grouting pipe is connected to a grouting pump through a grout supply pipe, and the other end is a closed end. A grout outlet is provided in the middle of the grouting pipe. Balloons are respectively sleeved at both ends of the grouting pipe. The balloons located at both ends of the grouting pipe are connected in series through a pressurizing pipe. The two balloons respectively block both sides of the connection between one of the annular pipes and the pressurizing pipe, so that the grouting pipe, the grout outlet and all the grout outlet valves corresponding to the annular pipe form a grouting channel.

[0011] Preferably, the ring pipe is a ring structure that is spliced ​​together from multiple bends and is adapted to the inner diameter of the reinforcing cage. The multiple ring pipes that overlap each other in the axial direction of the reinforcing cage are connected in series through the same grouting pipe.

[0012] Preferably, each ring pipe includes 2-4 bends that are spliced ​​together, and both ends of each bend are closed ends. Two adjacent bends in the same ring pipe are spliced ​​together by a sleeve.

[0013] Preferably, each of the bends includes multiple spliced ​​sections, and two adjacent spliced ​​sections are connected by the slurry outlet valve. The slurry outlet valve is a tee pipe, one of the pipes of the tee pipe extends radially along the reinforcing cage, and a check valve is provided on the pipe of the tee pipe extending out of the reinforcing cage. The check valve is correspondingly sleeved on the elastic sleeve.

[0014] Preferably, the balloon has a cylindrical structure, with its two ends fixed to the grouting pipe by end plates. The end plates of two adjacent balloons are connected by the pressurization pipe, and the balloon away from the closed end of the grouting pipe is connected to the air pump by the air supply pipe.

[0015] Preferably, the slurry supply pipe and the air supply pipe are integrally formed or connected as a whole by adhesive bonding.

[0016] Preferably, an automatic pipe rolling machine corresponding to the air supply pipe and / or the grout supply pipe is provided at the opening of the pile hole.

[0017] Preferably, the lower end of the grouting pipe extends into the bottom of the pile hole, and a grouting port is provided at the part of the grouting pipe that is inserted into the bottom of the pile hole.

[0018] A ring grouting method for approach bridge pile foundations, comprising grouting using any of the above-described grouting structures, including:

[0019] Step S1: Simultaneously tie the ring pipe and grouting pipe during the processing of the reinforcing cage;

[0020] Step S2: After the bottom is cleared, the steel cage is lowered to the bottom of the pile hole and concrete is poured into the pile hole.

[0021] Step S3: Insert the grout stop valve into the grouting pipe, so that the grout outlet in the middle of the grout stop valve is directly opposite the bottom loop of the grouting pipe.

[0022] Step S4: Inflate the two balloons to seal the two sides of the corresponding ring pipe, and then supply grout into the grouting pipe to form a grouting channel by the grouting pipe, the grout outlet and all the grouting valves of the corresponding ring pipe, and grout the outer periphery of the pile hole.

[0023] Step S5: Grouting is performed on multiple ring pipes sequentially from bottom to top until grouting of all ring pipes is completed.

[0024] Preferably, in step S1, the sonic logging tubes are tied simultaneously, and the multiple sonic logging tubes are evenly distributed in the circumferential direction of the reinforcing cage.

[0025] Beneficial effects: By setting up a ring pipe connecting multiple grout stop valves, grouting can be performed on multiple grout stop valves at the same elevation through the ring pipe. This not only allows for the design of different grouting pressures but also significantly improves grouting efficiency. The grout outlet valve presses the cement grout into the soil layer beside the pile, enhancing the strength of the mud cake around the pile through the grout, thereby improving the ultimate bearing capacity of the pile foundation and reducing settlement. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, 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 undue limitation of the invention. Wherein:

[0027] Figure 1 This is a schematic diagram of the grouting device in a specific embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of grouting the bottommost ring pipe in a specific embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram showing the completion of grouting of the bottommost ring pipe in a specific embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram illustrating pile end grouting in a specific embodiment of the present invention;

[0031] Figure 5 This is a simplified structural diagram of the slurry stop valve in a specific embodiment of the present invention;

[0032] Figure 6 This is a simplified structural diagram of the slurry outlet valve in a specific embodiment of the present invention;

[0033] Figure 7 This is a simplified structural diagram of the slurry outlet valve after adding an insert pipe in a specific embodiment of the present invention.

[0034] In the diagram: 1. Grouting pipe; 2. Ring pipe; 3. Grout outlet valve; 4. Sleeve; 5. Automatic pipe winding machine; 6. Grout stop valve; 7. Check valve; 8. Insertion pipe; 601. Balloon; 602. Pressurization pipe; 603. Air supply pipe; 604. Grout supply pipe; 605. End plate; 701. Rubber hose. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0036] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0038] like Figure 1-7 As shown, a ring-type grouting device for approach bridge pile foundation includes a ring pipe 2, a grouting pipe 1, and a grout stop valve 6. The ring pipe 2 is bound or welded to the inner side of the reinforcing cage. The ring pipe 2 is a circular pipe that matches the inner diameter of the reinforcing cage and is arranged concentrically with the reinforcing cage. Multiple grout outlet valves 3 are distributed on the ring pipe 2. The grout outlet valves 3 are used to inject grout into the outer circumference of the pile body when injecting cement grout. The grout outlet valves 3 extend radially to the outer circumference of the reinforcing cage. Furthermore, in order to ensure the grouting effect, the grout outlet valves 3 extend radially out of the outer circumference of the reinforcing cage, thereby improving the grouting effect.

[0039] Multiple ring pipes 2 are connected in series through grouting pipe 1. Grouting pipe 1 extends along the axial direction of the reinforcing cage and downwards, and multiple ring pipes 2 are connected in series accordingly. Thus, grouting can be performed at multiple outlet valves 3 at the same elevation through one grouting pipe 1. At the same time, grouting is performed independently at each ring pipe 2 through grout stop valve 6. Thus, different grouting pressures and different grouting volumes can be preset at different elevations according to actual needs.

[0040] The grout stop valve 6 is correspondingly installed inside the grouting pipe 1 and is slidably assembled along the axial direction of the grouting pipe 1. As the grout stop valve 6 slides along the grouting pipe 1, it can pass through multiple ring pipes 2, thereby enabling independent grouting of the ring pipes 2.

[0041] The grout stop valve 6 includes a grouting pipe and a pressurizing pipe 602. The grouting pipe is a metal pipe. One end of the grouting pipe is connected to the grouting pump through the grout supply pipe 604 so that grouting can be performed by the grouting pump. The other end of the grouting pipe is a closed end.

[0042] A grout outlet is provided in the middle of the grouting pipe. The grout outlet is one or more perforations. Balloons 601 are respectively sleeved at both ends of the grouting pipe. The balloons 601 located at both ends of the grouting pipe are connected in series through a pressurization pipe 602. The balloons 601 are made of rubber and can be reused by inflation and deflation to grout each ring pipe 2.

[0043] When the balloon 601 is inflated, it expands and presses against the inner wall of the grouting pipe 1, thus forming a seal. The grout stop valve 6 is then lowered to one of the ring pipes 2 to be grouted, so that the two balloons 601 respectively block both sides of the connection between the ring pipe 2 and the grouting pipe 1, so that the grouting pipe, the grout outlet and all the grout outlet valves 3 of the corresponding ring pipe 2 form a grouting channel.

[0044] In this embodiment, grouting operations are performed from bottom to top at multiple ring pipes 2 corresponding to different elevations. A ring pipe 2 is set every 5 meters. The ring pipe 2 and the corresponding grouting pipe are connected by a cross-shaped four-way structure for cement grout flow.

[0045] In an optional embodiment, the ring pipe 2 is a ring structure that is spliced ​​together from multiple bends and is adapted to the inner diameter of the reinforcing cage. On the axial projection of the reinforcing cage, all the bends of the ring pipe 2 overlap with each other. In this embodiment, the multiple bends of the multiple ring pipes 2 that overlap with each other on the axial direction of the reinforcing cage are connected in series through the same grouting pipe 1.

[0046] In this embodiment, each ring pipe 2 includes 2-4 bends that are spliced ​​together. Taking each ring pipe 2 as an example, which includes two bends, two grouting pipes 1 need to be set accordingly. The two grouting pipes 1 correspond to the two bends of the ring pipe 2 respectively. Both ends of each bend are closed ends, so that each grouting pipe only grouts the bend it is connected to. The two ends of the bend are sealed by welding with baffles, etc. Two adjacent bends in the same ring pipe 2 are spliced ​​by sleeves 4. The two ends of the sleeves 4 are respectively sleeved on the two adjacent bends and can be fixed by welding. The fixed ring pipe 2 can be connected to the reinforcing cage by binding or welding.

[0047] In this embodiment, each bend includes multiple splicing segments. The specific number of splicing segments is determined according to the set number and density of the slurry outlet valves 3. Adjacent splicing segments are connected by slurry outlet valves 3. The slurry outlet valves 3 are three-way pipe structures. The main pipe connecting the two splicing segments of the slurry outlet valves 3 is arc-shaped, used for docking and transition between the two adjacent splicing segments. Specifically, the two splicing segments can be fixed by welding. The middle pipe of the three-way pipe extends radially along the reinforcing cage and extends out of the outer circumference of the reinforcing cage. A check valve 7 is provided at the end of the middle pipe of the three-way pipe. The check valve 7 is correspondingly sleeved on the elastic sleeve.

[0048] In some embodiments, the check valve 7 is a bottle cap-shaped rubber component. After the slurry is pressurized, the check valve 7 deforms to form a channel for the slurry to flow out.

[0049] Furthermore, an insertion tube 8 is inserted through the middle of the check valve 7. One end of the insertion tube 8 corresponding to the grout outlet valve 3 is an open end, and the other end is a sharp sealing end. A perforation is provided on the inner wall of the insertion tube 8 located near the check valve end of the grout outlet valve 3. After the pile body concrete is poured, water is supplied by the grouting pump to open the plug. During the opening process, high-pressure water is used to make the sharp end of the insertion tube 8 extend outward into the soil around the pile body, and grout is injected through the perforation on the side of the insertion tube 8, thereby improving the diffusion range and grouting effect of the grout.

[0050] The insertion pipe 4 is merely an additional measure to enhance the grouting effect. The presence or absence of the insertion pipe 4 does not affect the circumferential foundation grouting requirements of the pile body. In cases where the geological conditions are hard, or when the pressure required by the check valve 7 is less than the pressure required for the insertion pipe 4 to be inserted into the soil, there may be situations where the check valve 7 is opened, but the insertion pipe 4 is not inserted into the soil around the pile body. In such cases, grouting can be performed only through the check valve 7. The cement slurry passes through the thin layer of concrete between the inner wall of the pile hole and the check valve 7, which can also achieve the effect of circumferential grouting of the pile body.

[0051] Therefore, in order to ensure that the insertion tube 4 can be inserted into the soil around the pile body as much as possible, this embodiment performs the unplugging operation within 12-24 hours after the pile body concrete is poured, preferably 18 hours. At this time, the concrete has a certain strength, so the pressure required for unplugging is relatively large. After the unplugging is completed, the pile body concrete will not backflow and block the unplugging channel, so it will drive the insertion tube 4 to be inserted into the soil radially as much as possible.

[0052] In this embodiment, the end of the check valve 7 is provided with a corresponding mounting hole for the insertion tube 8. The mounting hole is press-fitted with the insertion tube 8. A rubber tube 701 corresponding to the insertion tube 8 is integrally formed on the inner side of the check valve 7. The rubber tube 701 extends along the axial direction of the check valve 7, thereby ensuring that concrete will not flow into the grouting valve 3 or the insertion tube 8 during the grouting process.

[0053] The outer diameter of the insertion pipe 8 is no greater than two-thirds of the radial extension of the grout outlet valve 3 into the inner diameter of the pipe, so as to ensure that grouting can still be performed through the gap between the insertion pipe 8 and the grouting valve even if the insertion pipe 8 cannot extend.

[0054] In an optional embodiment, the balloon 601 has a cylindrical structure, with its two ends fixed to the grouting pipe by end plates 605. The end plates 605 are provided with perforations corresponding to the grouting pipe and are sealed and fixed by welding. The adjacent end plates 605 of the two balloons 601 are connected by a pressurization pipe 602. The balloon 601 away from the closed end of the grouting pipe is connected to the air pump by an air supply pipe 603.

[0055] In this embodiment, an automatic pipe rolling machine 5 is provided at the opening of the pile hole, corresponding to the air supply pipe 603 and / or the grout supply pipe 604.

[0056] To ensure the driving effect, the slurry supply pipe 604 and the air supply pipe 603 are integrally formed or connected as a whole by adhesive bonding.

[0057] At this time, the automatic pipe winding machine 5 synchronously drives the combined air supply pipe 603 and slurry supply pipe 604.

[0058] In an optional embodiment, the present invention can also perform pile end grouting. Specifically, after pile end grouting, grouting is performed around the pile body. The lower end of the grouting pipe 1 extends into the bottom of the pile hole, and a grouting port is provided at the part of the grouting pipe 1 inserted into the bottom of the pile hole.

[0059] Among them, a rubber sleeve is installed at the part of the grouting pipe 1 corresponding to the grouting port. When the pressure is supplied, the rubber sleeve is deformed to supply the grout, thereby forming a grouting area at the bottom of the pile.

[0060] In this embodiment, the closed end of the grouting pipe can be sealed by a detachably connected sealing head. Grouting can be performed from this end when needed, for example, when performing pile end grouting. During pile end grouting, the lower end of the grouting pipe 1 extends 50cm into the bottom of the pile hole.

[0061] A manual control valve is provided on the inflator pipe 602 between the two balloons 601. When grouting at the pile end, the grout stop valve 6 is lowered to the bottom elevation of the pile body, the manual control valve is closed, the sealing end plug is removed, and only one balloon 601 is inflated by supplying air. At this time, the grout is supplied so that the grout can pass through the grouting port and the rubber sleeve to grout the pile end.

[0062] The present invention also provides a ring grouting method for approach bridge pile foundations, wherein grouting is performed using any of the above-mentioned grouting structures, including:

[0063] Step S1: Simultaneously tie the ring pipe 2 and the grouting pipe 1 during the processing of the steel cage;

[0064] Step S2: After the bottom is cleared, the steel cage is lowered to the bottom of the pile hole and concrete is poured into the pile hole.

[0065] Step S3: Insert the grout stop valve 6 into the grouting pipe 1, so that the grout outlet in the middle of the grout stop valve 6 is directly opposite the bottom ring pipe 2 of the grouting pipe 1.

[0066] Step S4: Inflate the two balloons 601 to seal both sides of the corresponding ring pipe 2, and then supply grout into the grouting pipe to form a grouting channel by the grouting pipe, the grout outlet and all the grouting valves 3 of the corresponding ring pipe 2, and grout the outer periphery of the pile hole.

[0067] Step S5: Grouting is performed on multiple ring pipes 2 sequentially from bottom to top until grouting of all ring pipes 2 is completed.

[0068] In this embodiment, in step S2, the plug should be opened with clean water within 12 to 24 hours after the cast-in-place pile is formed. Grouting should be performed after the pile concrete reaches 85% of its design strength.

[0069] In this embodiment, the grouting parameters (grouting pressure and grouting volume) can be preset after the pile body is detected by the sonic logging tube. Grouting should be performed at low pressure and slow speed.

[0070] In this implementation, the method of opening the plug is the same as the method of grouting, both of which are carried out through the grout stop valve.

[0071] In another embodiment, in step S1, sonic logging tubes are tied simultaneously. Multiple sonic logging tubes are evenly distributed in the circumferential direction of the reinforcing cage, and multiple connectors are evenly distributed in the axial direction of the reinforcing cage. The connectors are welded to the inner side of the reinforcing cage and have slots or perforations corresponding to the sonic logging tubes and grouting pipes 1.

[0072] When grouting the pile foundation, the grout is prepared with PO42.5 ordinary Portland cement. An appropriate amount of admixture can be added as needed. The water-cement ratio of the grout is 0.5 to 0.6.

[0073] Grouting should follow the principle of "slow and gentle injection," and the grout flow rate at the outlet should not exceed 75 L / min. The grouting pressure at the pile tip should be 0.8–4.0 MPa, and the grouting pressure on the pile side should be 0.2–2.0 MPa. The termination standard for pile tip grouting should adopt the principle of dual control of grouting volume and grouting pressure, with grouting volume (cement usage) as the primary control and grouting pressure as a secondary control.

[0074] In this embodiment, the grouting pressure corresponding to different elevations of the ring pipe 2 is set according to the geological survey.

[0075] Generally, the rated pressure of a grouting pump should not be less than 12 MPa, and the rated flow rate should not be less than 100 L / min. The grouting pump is equipped with a pressure gauge and a flow meter, and has the functions of automatic metering, real-time display, and real-time transmission. The range of the pressure gauge should be 1.5-2.0 times the rated pump pressure.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A ring-type grouting device for approach bridge pile foundations, characterized in that, include: A ring pipe is concentrically arranged inside the reinforcing cage, and multiple grout outlet valves are distributed on the ring pipe, with the grout outlet valves extending radially out of the outer circumference of the reinforcing cage. Grouting pipe, which extends along the axial direction of the reinforcing cage and is connected in series with a plurality of the ring pipes; A grout stop valve is correspondingly disposed inside the grouting pipe and is slidably assembled along the axial direction of the grouting pipe. The grout stop valve includes a grouting pipe and a pressurizing pipe. One end of the grouting pipe is connected to a grouting pump through a grout supply pipe, and the other end is a closed end. A grout outlet is provided in the middle of the grouting pipe. Balloons are respectively sleeved at both ends of the grouting pipe. The balloons located at both ends of the grouting pipe are connected in series through a pressurizing pipe. The two balloons respectively block both sides of the connection between one of the annular pipes and the pressurizing pipe, so that the grouting pipe, the grout outlet and all the grout outlet valves corresponding to the annular pipe form a grouting channel. The ring pipe is a ring structure that is adapted to the inner diameter of the reinforcing cage by splicing multiple bends. Multiple bends that overlap each other in the axial direction of the reinforcing cage are connected in series through the same grouting pipe. Each of the aforementioned bends includes multiple spliced ​​sections, and two adjacent spliced ​​sections are connected by the slurry outlet valve. The slurry outlet valve is a tee pipe, and one of the pipes of the tee pipe extends radially out of the outer circumference of the reinforcing cage. A check valve is provided on the pipe of the tee pipe extending out of the outer circumference of the reinforcing cage. The check valve is a bottle cap-shaped rubber part with an insert tube inserted in the middle. One end of the insert tube corresponding to the grout outlet valve is an open end, and the other end is a sharp sealing end. There is a perforation on the inner wall of the insert tube near the end of the check valve at the grout outlet valve. After the pile concrete is poured, water is supplied by the grouting pump to open the plug. During the opening process, high pressure water is used to make the sharp end of the insert tube extend outward into the soil around the pile body, and grout is injected through the perforation on the side of the insert tube. The end of the check valve is provided with a corresponding mounting hole for the insertion tube. The mounting hole is interference-fitted with the insertion tube. A rubber tube corresponding to the insertion tube is integrally formed on the inner side of the check valve. The rubber tube extends axially along the check valve. The outer diameter of the insertion tube is not greater than two-thirds of the inner diameter of the pipe along which the slurry valve extends radially.

2. The ring-type grouting device for approach bridge pile foundations according to claim 1, characterized in that, Each ring pipe includes 2-4 bends that are spliced ​​together. Both ends of each bend are closed ends. Two adjacent bends within the same ring pipe are spliced ​​together by a sleeve.

3. The ring-type grouting device for approach bridge pile foundations according to claim 1, characterized in that, The balloon is a cylindrical structure, with its two ends fixed to the grouting pipe by end plates. The end plates of two adjacent balloons are connected by the pressurization pipe, and the balloon away from the closed end of the grouting pipe is connected to the air pump by the air supply pipe.

4. The ring-type grouting device for approach bridge pile foundations according to claim 3, characterized in that, The slurry supply pipe and the air supply pipe are integrally formed or connected as a whole by adhesive bonding.

5. The ring-type grouting device for approach bridge pile foundations according to claim 3, characterized in that, An automatic pipe rolling machine corresponding to the air supply pipe and / or the grout supply pipe is provided at the opening of the pile hole.

6. The ring-type grouting device for approach bridge pile foundations according to claim 1, characterized in that, The lower end of the grouting pipe extends into the bottom of the pile hole, and a grouting port is provided at the part of the grouting pipe that is inserted into the bottom of the pile hole.

7. A method for ring grouting of approach bridge pile foundations, wherein grouting is performed using any one of the grouting devices described in claims 1-6, characterized in that... include: Step S1: Simultaneously tie the ring pipe and grouting pipe during the processing of the reinforcing cage; Step S2: After the bottom is cleared, the steel cage is lowered to the bottom of the pile hole and concrete is poured into the pile hole. Step S3: Insert the grout stop valve into the grouting pipe, so that the grout outlet in the middle of the grout stop valve is directly opposite the bottom loop of the grouting pipe. Step S4: Inflate the two balloons to seal the two sides of the corresponding ring pipe, and then supply grout into the grouting pipe to form a grouting channel by the grouting pipe, the grout outlet and all the grouting valves of the corresponding ring pipe, and grout the outer periphery of the pile hole. Step S5: Grouting is performed on multiple ring pipes sequentially from bottom to top until grouting of all ring pipes is completed.

8. The ring grouting method for approach bridge pile foundations according to claim 7, characterized in that, In step S1, the sonic logging tubes are tied simultaneously, and multiple sonic logging tubes are evenly distributed around the circumference of the reinforcing cage.

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