A dual-purpose grouting pipe

Abstract

This utility model discloses a dual-purpose grouting pipe for geotechnical engineering construction, comprising a primary grouting check pipe, a PVC grouting pipe, and a secondary grouting check pipe. The primary grouting check pipe is located at the front end of the PVC grouting pipe, and a pipe plug is fixedly connected to the end of the primary grouting check pipe. A piston is slidably sealed inside the primary grouting check pipe, and a spring is clamped between the piston and the pipe plug inside the primary grouting check pipe. This utility model achieves two grouting operations with a single grouting pipe, reducing the number of pipes in the borehole, improving the strength of the anchor structure, and using a piston, spring, and rubber sleeve sealing mechanical check structure to replace the traditional tape sealing, avoiding the risk of blockage and leakage. It also saves one grouting pipe and installation steps, reducing material costs, improving construction efficiency, and eliminating the need for secondary sealing, thus adapting to multiple grouting needs.

Description

Technical Field

[0001] This utility model relates to the field of geotechnical engineering construction, specifically a dual-purpose grouting pipe. Background Technology

[0002] In the field of geotechnical anchoring, prestressed anchor cables are the most commonly used and crucial components connecting retaining structures to the soil and rock mass. Essentially, a prestressed anchor cable is a tension member with one end "embedded" in the soil or rock layer and the other end connected to the engineering structure. Its basic function is to transfer the tensile force generated by the soil pressure, water pressure, or unbalanced load on the structure to the soil or rock layer, thereby maintaining the safety and stability of the structure. Clearly, the two ends of this important tension member are key aspects of anchor cable (rod) construction. Currently, the construction process for "embedding" the anchor cable in the rock or soil mostly involves traditional drilling and grouting, and the quality of the grouting is a critical factor in the success or failure of the anchor cable (rod) installation.

[0003] To ensure grouting quality, a common grouting process involves secondary high-pressure grouting (or secondary high-pressure fracturing grouting) following a primary atmospheric pressure grouting. This increases the bond strength and frictional resistance between the anchor body and the soil / rock mass. In prestressed anchor cable construction, secondary high-pressure grouting effectively fractures, compresses, and compacts the cylindrical anchor body formed by atmospheric pressure grouting, and fills fissures in fractured rock layers. This causes the cylindrical anchor body to expand into an irregular shape, thereby improving the mechanical properties of the surrounding soil / rock mass and significantly increasing the anchor cable's bearing capacity.

[0004] Currently, prestressed anchor cable grouting pipes are fabricated and installed together with the anchor cable skeleton. The procedure involves laying the steel strands straight, setting up an isolation frame every 1.5m, placing the steel strands sequentially into the grooves of the positioning brackets, and then securing them to the brackets with binding wire. The primary grouting pipes, made of PVC pipe, pass through the middle hole of the positioning bracket one by one along the anchor cable axis from beginning to end. The ends of the primary grouting pipes are sealed with tape to prevent mud from the anchor cable holes from entering and clogging the pipes during insertion into the anchor cable skeleton, thus affecting the primary grouting process. The secondary grouting pipe is first inserted into the PVC pipe along the anchor cable axis from the middle hole of the positioning bracket, starting from the free section and moving towards the bottom. After insertion, holes with a diameter of Φ5 are drilled in the PVC pipe within one-third of the bottom of the anchor cable using an electric drill. These holes are used as outlet holes for secondary grouting. The holes are then sealed with tape to prevent cement slurry from entering the secondary grouting pipe through the holes during primary grouting. Finally, the secondary grouting pipe is tied together with the steel strand to prevent it from falling off during anchoring.

[0005] The general method for anchor cable grouting is as follows: Ordinary Portland cement with a water-cement ratio of approximately 1:0.5 is used for anchor cable grouting, along with a cement paste of grade 42.5. A certain amount of admixture may be added if necessary. When using a two-stage grouting process, the primary grouting pressure is 0.5 MPa, and the secondary grouting pressure is 1.5 MPa. Secondary pressure grouting is performed after a certain time has elapsed since the primary grouting.

[0006] During secondary grouting, the sealing tape of the secondary grouting hole is first cracked by high pressure, so that the cement grout can penetrate into the original cement grout and soil through the hole of the PVC pipe under high pressure, so as to achieve the effect of compacting the grout. In addition, the floating water formed above the hole during the first grouting will also be discharged from the hole by the high-pressure cement grout, making the original grout more full.

[0007] The above grouting method has the following drawbacks: First, the secondary grouting pipe is sealed with adhesive tape. This tape may come loose during anchor cable frame installation, allowing some cement slurry to enter the secondary grouting pipe through the opening during primary grouting. This slurry can solidify and cause the secondary grouting pipe to fail. Furthermore, the two grouting pipes occupy borehole space, affecting the bond strength between the anchor body and the soil. Second, the presence of two PVC pipes within the anchor body affects its structural strength. Additionally, the need to install two PVC pipes increases costs, and the tape must be punctured before secondary grouting, making the operation complex and difficult to guarantee a proper seal.

[0008] Existing technologies such as CN205838365U and CN201330122Y, which employ grouting pipe structures, have not resolved the drawbacks of multiple pipes existing simultaneously. Therefore, those skilled in the art have provided a dual-purpose grouting pipe to address the problems mentioned in the background section. Utility Model Content

[0009] The purpose of this utility model is to provide a dual-purpose grouting pipe to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, this utility model provides the following technical solution:

[0011] A dual-purpose grouting pipe includes a primary grouting check pipe, a PVC grouting pipe, and a secondary grouting check pipe. The primary grouting check pipe is located at the front end of the PVC grouting pipe, and a pipe plug is fixedly connected to the end of the primary grouting check pipe. A piston is slidably sealed inside the primary grouting check pipe, and a spring is clamped between the piston and the pipe plug inside the primary grouting check pipe. A limit clamp is fixedly connected to the inner wall of the primary grouting check pipe on one side of the piston. A grout outlet is opened on the outer wall of the primary grouting check pipe at the piston. The secondary grouting check pipe is installed on... The anchoring end of the PVC grouting pipe, and the secondary grouting check pipe has two symmetrical grout outlets on its waist. A rubber sleeve is provided on the outer surface of the secondary grouting check pipe at the grout outlet. The waist of the rubber sleeve has a grout outlet hole. The rubber sleeve and the secondary grouting check pipe are reinforced and connected by a rubber hoop. The pipe plug acts as a support for the spring. The bottom of the spring is fixed to the pipe plug. The spring force can push the piston to the position that closes the grout outlet and stops it at the limit card. When the piston is under pressure, the piston compresses the spring and retracts until the grout outlet is exposed.

[0012] As a further embodiment of this utility model: the piston inside the primary grouting check pipe normally closes the grout outlet one under the action of the spring, and during grouting, the grout pressure pushes the piston to compress the spring and open the grout outlet one.

[0013] As a further aspect of this invention: the inner diameter of the rubber sleeve of the secondary grouting check pipe is smaller than the outer diameter of the pipe body. Elastic deformation enables the grout outlet to be sealed and opened twice. After the rubber sleeve covers the secondary grouting check pipe, adhesive is applied to the inner walls at both ends of the rubber sleeve at positions corresponding to the outer wall of the secondary grouting check pipe to firmly bond it, preventing it from easily falling off or moving. A grout outlet hole is provided at the waist of the rubber sleeve, circumferentially offset from the grout outlet hole on the secondary grouting check pipe. When secondary grouting is performed, the high-pressure cement grout inside the secondary grouting check pipe pushes open the rubber sleeve. After the rubber sleeve is pushed open by the high-pressure cement grout, the cement grout can flow out from the grout outlet on the rubber sleeve. After secondary grouting is completed and the pressure inside the pipe is released, the rubber sleeve, under elastic action, seals the grout outlet on the secondary grouting check pipe again, preventing the cement grout from returning into the pipe.

[0014] As a further embodiment of this utility model, the connection between the primary grouting check pipe and the secondary grouting check pipe and the PVC grouting pipe is reinforced by a pipe clamp.

[0015] As a further aspect of this invention: the PVC grouting pipe is a hollow tubular hose made of PVC material, which can withstand the flow of high-pressure fluid inside the pipe. This hose has a certain degree of elasticity, and a tubular body with an outer diameter slightly larger than or equal to its own diameter can be inserted inside. After the grouting pipe and the inserted body are tightened with a pipe clamp, they are not easily detached under a large axial tensile force.

[0016] As a further embodiment of this utility model: the second slurry outlet is axially offset from the slurry outlet hole of the sleeve.

[0017] As a further embodiment of this utility model: In order to facilitate the washing of cement slurry, an internal cement slurry cleaning pipe is also provided inside the device. The internal cement slurry cleaning pipe is a PVC pipe with an outer diameter smaller than the inner diameter of the grouting pipe. Its function is to inject clean water pumped by the mud pump into the grouting pipe to clean the cement slurry inside the grouting pipe and prevent cement slurry from clogging the grouting pipe.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] This invention achieves two grouting processes with a single grouting pipe, reducing the number of pipes inside the borehole, improving the structural strength of the anchor body, and replacing the traditional tape sealing with a piston, spring, and rubber sleeve sealing mechanical check structure to avoid the risk of blockage and leakage. At the same time, it saves one grouting pipe and installation process, reduces material costs, improves construction efficiency, and eliminates the need for secondary sealing, making it suitable for multiple grouting needs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] In the diagram: 1. Primary grouting check pipe; 101. Grout outlet one; 2. PVC grouting pipe; 3. Secondary grouting check pipe; 301. Grout outlet two; 4. Pipe clamp; 5. Spring; 6. Piston; 7. Limiting clip; 8. Rubber sleeve; 801. Grout outlet hole of the sleeve; 9. Rubber clamp. Detailed Implementation

[0022] Please see Figure 1In this embodiment of the utility model, a dual-purpose grouting pipe includes a primary grouting check pipe 1, a PVC grouting pipe 2, and a secondary grouting check pipe 3. The primary grouting check pipe 1 is located at the front end of the PVC grouting pipe 2, and a pipe plug is fixedly connected to the end of the primary grouting check pipe 1. A piston 6 is slidably sealed inside the primary grouting check pipe 1. A spring 5 is clamped inside the primary grouting check pipe 1 between the piston 6 and the pipe plug. A limit clamp 7 is fixedly connected to the inner wall of the primary grouting check pipe 1 on one side of the piston 6. A grout outlet 101 is opened on the outer wall of the primary grouting check pipe 1 at the piston 6. The secondary grouting check pipe 3 is installed on the PVC grouting pipe 2. The anchoring end of the C grouting pipe 2 and the waist of the secondary grouting check pipe 3 are symmetrically provided with two grout outlets 301. A rubber sleeve 8 is provided on the outer surface of the secondary grouting check pipe 3 at the grout outlet 301. The waist of the rubber sleeve 8 is provided with a sleeve grout outlet hole 801. The rubber sleeve 8 and the secondary grouting check pipe 3 are reinforced and connected by a rubber hoop 9. The pipe plug serves as a support for the spring 5. The bottom of the spring 5 is fixed to the pipe plug. The elastic force of the spring 5 can push the piston 6 to the position that closes the grout outlet 101 and stops at the limit card 7. When the piston 6 is under pressure, the piston 6 compresses the spring 5 to retract until the grout outlet is exposed.

[0023] In the first grouting check pipe 1, the piston 6 inside normally closes the grout outlet 101 under the action of the spring 5. During grouting, the grout pressure pushes the piston 6 to compress the spring 5 and open the grout outlet 101.

[0024] In this design, the inner diameter of the rubber sleeve 8 of the secondary grouting check pipe 3 is smaller than the outer diameter of the pipe body. Elastic deformation allows for the sealing and opening of the grout outlet 301. After the rubber sleeve 8 is fitted onto the secondary grouting check pipe 3, adhesive is applied to the inner walls at both ends of the rubber sleeve 8 at corresponding positions on the outer wall of the secondary grouting check pipe 3 to ensure it is secure and does not easily fall off or move. A grout outlet 801 is located at the waist of the rubber sleeve 8, circumferentially offset from the grout outlet on the secondary grouting check pipe 3. During secondary grouting, the high-pressure cement grout inside the secondary grouting check pipe 3 pushes open the rubber sleeve. After the rubber sleeve is pushed open by the high-pressure cement grout, the cement grout can flow out from the grout outlet on the rubber sleeve 8. After secondary grouting is completed and the pressure inside the pipe is released, the rubber sleeve 8, under elastic action, seals the grout outlet on the secondary grouting check pipe 3 again, preventing the cement grout from returning into the pipe.

[0025] Among them, the connection between the primary grouting check pipe 1 and the secondary grouting check pipe 3 and the PVC grouting pipe 2 is reinforced by the installed pipe clamp 4.

[0026] Among them, the PVC grouting pipe 2 is a hollow tubular hose made of PVC material, which can withstand the flow of high-pressure fluid inside the pipe. This hose has a certain degree of elasticity, and a tubular body with an outer diameter slightly larger than or equal to its diameter can be inserted inside. After the grouting pipe and the inserted body are locked together with the appropriate clamping force using the pipe clamp 4, the two are not easy to fall off under the action of a large axial tensile force.

[0027] Among them, the slurry outlet 2 301 and the slurry outlet hole 801 of the sleeve are axially offset.

[0028] In order to facilitate the washing of cement slurry, an internal cement slurry cleaning pipe is also installed inside the device. The internal cement slurry cleaning pipe is a PVC pipe with an outer diameter smaller than the inner diameter of the grouting pipe. Its function is to inject clean water pumped by the mud pump into the grouting pipe to clean the cement slurry inside the grouting pipe and prevent cement slurry from clogging the grouting pipe.

[0029] The method of using this utility model includes the following steps:

[0030] Step 1: Similar to conventional anchor cable construction, after the anchor cable skeleton is tied, a grouting pipe is passed through the middle hole of the positioning bracket one by one from beginning to end along the anchor cable axis until the end of the anchor cable.

[0031] Step 2: Insert a primary grouting check pipe 1 into the end of the grouting pipe, and tighten the primary grouting check pipe 1 and the grouting pipe clamp 4 with the pipe clamp 4 to prevent them from falling off.

[0032] Step 3: Within one-third of the end of the anchorage section, evenly install three or more secondary grouting check pipes 3. The number is determined based on the length of the anchorage section. Cut the grouting pipe at the designated installation point and trim off a section slightly shorter than the original length of the secondary grouting check pipe. Insert one end of the secondary grouting check pipe 3 into one side of the grouting pipe and tighten it with a pipe clamp 4. Then tighten the other end of the grouting pipe with a pipe clamp 4. Repeat this process for several secondary grouting check pipes 3.

[0033] Step 4: Install the anchor cable skeleton with the primary grouting check pipe 1 and the secondary grouting check pipe 3 into the anchor cable hole.

[0034] Step 5: Connect the head of the grouting pipe tightly to the outlet of the grouting pump, turn on the grouting pump and pump the clean cement slurry mixed in the cement slurry mixing tank from the cement slurry pool into the grouting pipe. The grouting pressure and quantity shall be in accordance with the regulations.

[0035] Step 6: After the first grouting is completed, put the grout inlet nozzle of the grouting pipe into the clean water tank, connect the cement slurry cleaning pipe inside the pipe, start the grouting pump to draw clean water into the cement slurry cleaning pipe inside the pipe, slowly insert the cement slurry cleaning pipe from the head of the grouting pipe to the tail of the grouting pipe, clean the cement slurry inside the pipe, and then pull it out.

[0036] Step 7: Once the specified time has elapsed after the first grouting is completed, the second grouting can be performed.

[0037] Step 8: The secondary grouting method involves tightly connecting the outlet of the grouting pump to the grouting pipe, and injecting cement slurry into the grouting pipe under pressure according to the designed pressure.

[0038] Step 9. Under normal circumstances, secondary grouting can be performed once as required. However, under special circumstances, this utility model can also perform multiple grouting as needed. It is only required that after each grouting, the cement slurry in the grouting pipe be cleaned and the cement slurry in the grouting pipe be rinsed in time.

[0039] This application achieves two grouting processes through a single grouting pipe, reducing the number of pipes inside the borehole, improving the structural strength of the anchor body, and replacing the traditional tape sealing with a piston 6 plus spring 5 and rubber sleeve 8 sealing mechanical check structure to avoid the risk of blockage and leakage. At the same time, it saves one grouting pipe and installation process, reduces material costs, improves construction efficiency, and eliminates the need for secondary sealing, making it suitable for multiple grouting needs.

[0040] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A dual-purpose grouting pipe, comprising a primary grouting check pipe (1), a PVC grouting pipe (2), and a secondary grouting check pipe (3), characterized in that: The primary grouting check pipe (1) is located at the front end of the PVC grouting pipe (2), and a pipe plug is fixedly connected to the end of the primary grouting check pipe (1). A piston (6) is slidably sealed inside the primary grouting check pipe (1). A spring (5) is clamped between the piston (6) and the pipe plug inside the primary grouting check pipe (1). A limit clamp (7) is fixedly connected to the inner wall of the primary grouting check pipe (1) on one side of the piston (6). A limit clamp (7) is fixedly connected to the outer wall of the primary grouting check pipe (1) on one side of the piston (6). A grout outlet (101) is provided at the anchor end of the PVC grouting pipe (2). The secondary grouting check pipe (3) is installed at the anchor end of the PVC grouting pipe (2). Two grout outlets (301) are symmetrically provided on the waist of the secondary grouting check pipe (3). A rubber sleeve (8) is provided on the outer surface of the secondary grouting check pipe (3) at the grout outlet (301). A grout outlet hole (801) is provided on the waist of the rubber sleeve (8). The rubber sleeve (8) and the secondary grouting check pipe (3) are reinforced and connected by a rubber hoop (9).

2. The dual-purpose grouting pipe according to claim 1, characterized in that: The piston (6) inside the primary grouting check pipe (1) normally closes the grout outlet (101) under the action of the spring (5). During grouting, the grout pressure pushes the piston (6) to compress the spring (5) and open the grout outlet (101).

3. The dual-purpose grouting pipe according to claim 1, characterized in that: The inner diameter of the rubber sleeve (8) of the secondary grouting check pipe (3) is smaller than the outer diameter of the pipe body, and the grout outlet (301) is sealed and opened through elastic deformation.

4. The dual-purpose grouting pipe according to claim 1, characterized in that: The connection between the primary grouting check pipe (1) and the secondary grouting check pipe (3) and the PVC grouting pipe (2) is reinforced by a pipe clamp (4).

5. A dual-purpose grouting pipe according to claim 1, characterized in that: The PVC grouting pipe (2) is a hollow tubular hose made of PVC material.

6. A dual-purpose grouting pipe according to claim 1, characterized in that: The second slurry outlet (301) is axially offset from the slurry outlet hole (801) of the sleeve.

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