A method for testing the thickness of slurry in pipe jacking process

Abstract

The application provides a method for testing slurry thickness in pipe jacking process, which integrates a slurry thickness detection mechanism on the wall of a pipe section to realize real-time detection. The method for testing slurry thickness is as follows: in the process of pushing the pipe section, the detection rod is retracted into the threaded mounting hole, the scale value L1 of the scale line of the indicating structure on the mounting sleeve is read when the outer end of the detection rod is located on the cylindrical surface of the outer circumferential surface of the pipe section, the slurry thickness is tested when the pipe section stops jacking, and specifically: the constraint on the detection rod is released, the detection rod is extended under the action of the spring, the detection rod stops extending when it abuts against the wall of the pipe mounting hole, the scale value L2 of the scale line of the indicating structure on the mounting sleeve is read, and L2-L1 is the slurry thickness. The application has the advantages of being capable of realizing real-time online detection of the slurry thickness in the pipe jacking process, and solving the problem that the slurry thickness data cannot be obtained in real time.

Description

Technical Field

[0001] This invention relates to the field of pipe jacking construction monitoring technology, and in particular to a method for testing grout thickness during pipe jacking. Background Technology

[0002] Pipe jacking, a key trenchless construction technology in municipal pipelines and integrated utility tunnels, relies on a jacking device in the starting shaft to propel the pipe along its designed axis towards the receiving shaft, while grout is injected between the pipe's outer perimeter and the soil wall to form a support layer. During construction, accurately understanding the real-time state of the original soil layer outside the pipe is crucial. This includes the actual distance between the pipe and the undisturbed soil, soil structural characteristics such as looseness or obstacle distribution, and the distribution of water and soil pressure acting on the pipe surface. These data directly affect the dynamic adjustment of key parameters such as jacking thrust and grouting pressure, providing a fundamental guarantee for preventing ground subsidence and mitigating construction risks. However, current monitoring practices face multiple severe challenges: construction companies mainly rely on preliminary geological data or internal jacking parameters for indirect extrapolation, or obtain delayed feedback through surface subsidence monitoring. These methods cannot provide in-situ direct data at the pipe-soil interface, leading to information distortion and slow response. The extreme nature of jacking conditions further exacerbates the technical bottleneck; high-intensity friction and compression easily damage conventional exposed sensors. Current testing methods rely on laboratory simulations and cannot obtain real-time field data. During actual construction, factors such as soil dissolution and water seepage can affect the designed grout thickness, making it impossible to adjust the size of the subsequent pipe jacking holes based on measured data to ensure the grout thickness meets requirements. Furthermore, environmental factors during grout use also make it impossible to determine whether the grout meets requirements. Parameters can only be set based on simulated experimental data provided by the laboratory, without on-site testing and feedback for adjustments to ensure actual parameters better meet construction requirements. Summary of the Invention

[0003] The first objective of this invention is to provide a method for real-time online detection of grout thickness during pipe jacking, which solves the problem of not being able to obtain grout thickness data in real time.

[0004] The second objective of this invention is to provide a method for testing grout thickness during pipe jacking that enables real-time grout sampling, thereby solving the problem of not being able to sample grout in real time during pipe jacking construction.

[0005] The above technical problems are solved by the following technical solution: a method for testing slurry thickness during pipe jacking, wherein the pipe jacking process includes excavating a pipe mounting hole for installing pipe sections using a tunneling head, and then simultaneously pushing pipe sections from the starting shaft to the receiving shaft into the pipe mounting hole using a jacking device. All pipe sections are joined together to form a jacking pipe. During the pipe section jacking process, slurry is injected into the pipe mounting hole to form a lubrication layer to reduce the resistance during the pipe section jacking process. The method is characterized by integrating a slurry thickness detection mechanism on the wall of the pipe section for real-time detection. The slurry thickness detection mechanism includes an installation sleeve and a detection rod. The front end of the installation sleeve has an external thread section, which is a solid structure. The external thread section is sealed and threadedly connected to a threaded installation hole on the wall of the pipe section. One end of the detection rod is sealed and slidably connected to the external thread. Within the section, the detection rod extends radially along the jacking pipe section. The inner end of the detection rod has a scale line indicating the length of the extended outer end. A return spring within the mounting sleeve drives the detection rod to extend outwards towards the outside of the jacking pipe section. The detection rod stops extending when it reaches the wall of the jacking pipe mounting hole. The method for testing slurry thickness is as follows: During the jacking pipe section's advancement, the detection rod retracts into the threaded mounting hole. The scale value L1, aligned with the indicator structure on the mounting sleeve, is read when the outer end of the detection rod is on the cylindrical surface of the outer circumference of the jacking pipe section. The slurry thickness is tested when the jacking pipe section stops advancing. Specifically: the constraint on the detection rod is released, allowing it to extend under the action of the return spring. The detection rod stops extending when it abuts against the wall of the jacking pipe mounting hole. The scale value L2, aligned with the indicator structure on the mounting sleeve, is read. L2 - L1 is the slurry thickness. This method can detect the slurry thickness during the jacking process without affecting the jacking pipe advancement.

[0006] Preferably, during the jacking process of the pipe section, a retractable positioning structure keeps the detection rod in a retracted state within the threaded mounting hole. This retractable positioning structure includes a positioning hole on the circumference of the detection rod and a positioning pin detachably connected to the inner end face of the mounting sleeve. When the positioning pin is inserted into the positioning hole, the detection rod is retracted within the threaded mounting hole. This allows for convenient retraction of the detection rod.

[0007] Preferably, the inner end of the mounting sleeve is provided with a plurality of threaded rods distributed circumferentially along the mounting sleeve. The threaded rods extend axially along the mounting sleeve. Two clamping nuts are threaded onto the threaded rods. The threaded rods pass through the end ring. The inner end face of the end ring forms the inner end face of the mounting sleeve. The two clamping nuts clamp the end ring, thereby fixing the end ring onto the threaded rods. The indicating structure is mounted on the end ring. When the mounting sleeve is installed on the jacking pipe section, the position of the clamping nuts is adjusted so that when the outer end of the detection rod is located on the cylindrical surface of the outer circumferential surface of the jacking pipe section, the scale value of the aligned scale line of the indicating structure is zero. During the jacking process, it is difficult to accurately determine whether the detection rod is flush with the outer surface of the jacking pipe section from inside the jacking pipe. The detection rod can only be adjusted to be flush with the outer circumference of the jacking pipe section and the scale value L1 recorded at this point, before the jacking pipe section is installed into the jacking pipe mounting hole. However, the jacking pipe undergoes multiple processes from fabrication to installation in the jacking pipe mounting hole, including storage, transportation, and construction. This can easily lead to confusion regarding the correspondence between the detection rod and the initial value. There are multiple, sometimes even hundreds, of detection rod points in a single jacking pipe. This technical solution avoids the data errors caused by confusion in the correspondence between the detection rod and the initial scale value.

[0008] Preferably, the indicating structure includes a comparison cable fixed at the upper part of the end face of the mounting sleeve and a rope hole located at the lower part of the end face of the mounting sleeve. The inner end face of the mounting sleeve is flat and perpendicular to the comparison rod. The two ends of the comparison cable pass through the two ends of the measuring rod and then through the rope hole. The process of reading the scale value of the ruler is as follows: pull the two ends of the comparison cable so that the comparison cable simultaneously abuts against the inner end face of the mounting sleeve and the circumference of the detection rod. At this time, the scale value of the scale line aligned with the comparison cable is the reading of the ruler. When reading, the comparison cable and the scale are abutted together (i.e., without gaps) to reduce reading errors.

[0009] Preferably, the middle part of the comparison cable is fixed to the upper part of the mounting sleeve end face by a tension spring. When the reading is maintained and the comparison cable is released, the comparison cable can be released under the action of the tension spring, avoiding the need for manual release to prevent the comparison cable interference detection rod from moving.

[0010] Preferably, the upper side of the rope hole is an arc shape tangent to the inner end face of the mounting sleeve. This reliably ensures that the comparison cable can be pulled by abutting the end faces of the same end ring, and minimizes wear at the hanging corner during pulling.

[0011] Preferably, the system also includes a slurry sampling mechanism. This mechanism comprises a sliding hole on the inner end face of the mounting sleeve, a sliding rod slidably connected within the sliding hole, a transparent slurry storage tube located inside the jacking pipe body and connected to the sliding hole via a connecting channel, a compression spring driving the sliding rod to move outwards towards the jacking pipe section, and a connecting channel opening structure driving the sliding rod to move inwards towards the jacking pipe section. The slurry storage tube has a slurry discharge port, and the discharge port has a cap. During sampling, the sliding rod moves inwards towards the jacking pipe section under the action of the opening structure, allowing the connecting channel to connect with the jacking pipe mounting hole via the sliding hole. Slurry from the jacking pipe mounting hole enters the slurry storage tube. The appearance and color of the slurry are observed through the storage tube to ensure it meets requirements. The opening of the slurry tube is then closed. At this point, the sliding rod returns to its original position under the action of the compression spring, closing the connecting channel. The cap is removed, allowing the slurry in the slurry tube to drain into the sampling tube, which is then taken to the laboratory for further compositional analysis. This completes one sampling operation, enabling online sampling of injected slurry.

[0012] Preferably, the sliding hole at one end of the outer surface of the jacking pipe section has an inwardly flanged section to form a small-diameter segment, and the sliding rod abuts against the inwardly flanged section and is thus limited in position. This ensures that the spring can reliably overcome the pressure of the slurry in the jacking pipe mounting hole and return to its original position by providing the elastic force of the spring, without excessively moving into the jacking pipe mounting hole and interfering with the jacking pipe advancement.

[0013] Preferably, the end face of the slide bar is provided with a plug that fills the small-diameter section. The end face of the plug is flush with the end face of the external thread section, and the end face of the external thread section is flush with the outer circumferential surface of the jacking pipe section. This avoids the formation of a blind zone at the end of the sliding hole, which would cause slurry from non-sampling points to remain in the blind zone and be removed during sampling, resulting in poor sample accuracy.

[0014] Preferably, the slide rod is a ferromagnetic structure, the sliding hole is a blind hole, and the opening structure of the connecting channel is an electromagnet for attracting the slide rod, the electromagnet being fixed to the inner end face of the mounting sleeve. This achieves contactless driving of the slide rod, the driving force can be easily adjusted, and eliminates the need for sealing the inner end of the sliding hole.

[0015] Beneficial effects include the ability to detect mud thickness in real time and to sample mud in real time. Attached Figure Description

[0016] Figure 1 A schematic diagram showing the operational status of the slurry thickness detection mechanism; Figure 2 yes Figure 1 A magnified view of a portion of point A; Figure 3 yes Figure 1 A magnified view of a portion of point B; Figure 4 yes Figure 3 A magnified view of a portion at point C; Figure 5 yes Figure 3 A magnified view of a portion at point D; Figure 6 yes Figure 1 A magnified view of a portion of point E.

[0017] In the diagram: 1. Jacking pipe mounting hole; 2. Jacking pipe section; 3. Grout; 28. Mounting sleeve; 4. Detection rod; 5. External thread section; 6. Threaded mounting hole; 7. Scale line; 8. Reset spring; 9. Contraction positioning structure; 10. Positioning hole; 11. Positioning pin; 29. ​​Threaded rod; 12. Clamping nut; 13. Inner end face of end ring; 14. Comparison cable; 15. Rope hole; 16. Tension spring; 17. Upper side of rope hole; 18. Sliding hole; 19. Sliding rod; 20. Connecting channel; 21. Grout storage pipe; 22. Compression spring; 23. Connecting channel opening structure; 24. Hole cover; 25. Inner flange; 26. Plug; 27. End face of external thread section; 30. End ring. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] See Figures 1 to 6A method for testing grout thickness during pipe jacking is disclosed. The pipe jacking process includes excavating a pipe mounting hole 1 for installing pipe sections using a tunneling head, and then simultaneously pushing pipe sections 2 from the starting shaft to the receiving shaft into the pipe mounting hole using a jacking device. All pipe sections are joined together to form a jacking pipe. During the pipe section jacking process, grout 3 is injected into the pipe mounting hole to form a lubricating layer to reduce the resistance during pipe section jacking. A grout thickness detection mechanism is integrated on the wall of the pipe section for real-time detection. The grout thickness detection mechanism includes an installation sleeve 28 and a detection rod 4. The front end of the installation sleeve has an external thread section 5, which is a solid structure. The external thread section is sealed and threadedly connected to a threaded installation hole 6 on the wall of the pipe section. One end of the detection rod is sealed and slidably connected to the external thread section. The detection rod extends radially along the pipe section, and the inner end of the detection rod has a scale line 7 to indicate the length of the outer end of the detection rod. The mounting sleeve is equipped with a return spring 8 that drives the detection rod to extend outward toward the outside of the jacking pipe section. The detection rod stops extending when it hits the wall of the jacking pipe mounting hole. The method for testing the slurry thickness is as follows: During the advancement of the jacking pipe section, the detection rod is retracted into the threaded mounting hole. The scale value L1 of the indicator structure on the mounting sleeve is read when the outer end of the detection rod is located on the cylindrical surface of the outer circumference of the jacking pipe section. The slurry thickness test is performed when the jacking pipe section stops advancing. Specifically: the constraint on the detection rod is released, and the detection rod extends under the action of the return spring. The detection rod stops extending when it abuts the wall of the jacking pipe mounting hole. The scale value L2 of the indicator structure on the mounting sleeve is read. L2 - L1 is the slurry thickness. During the jacking process of the pipe section, the retraction positioning structure 9 keeps the detection rod in a retracted state within the threaded mounting hole (i.e., the external thread section). The retraction positioning structure includes a positioning hole 10 on the circumferential surface of the detection rod and a positioning pin 11 detachably connected to the inner end face of the mounting sleeve. When the positioning pin is inserted into the positioning hole, the detection rod is retracted within the threaded mounting hole. The inner end of the mounting sleeve is provided with several threaded rods 29 distributed circumferentially along the mounting sleeve, and the threaded rods extend axially along the mounting sleeve. Two clamping nuts 12 are threadedly adjusted on the threaded rods. The threaded rods pass through the end ring 30, and the inner end face 13 of the end ring forms the inner end face of the mounting sleeve. The two clamping nuts clamp the end ring, fixing the end ring to the threaded rods. The indicating structure is installed on the end ring. When the mounting sleeve is installed on the pipe section, the position of the clamping nuts is adjusted so that when the outer end of the detection rod is located on the cylindrical surface of the outer circumferential surface of the pipe section, the scale value of the aligned scale line of the indicating structure is zero. The indicator structure includes a comparison cable 14 fixed in the middle to the upper part of the end face of the mounting sleeve and a rope hole 15 located at the lower part of the end face of the mounting sleeve. The inner end face of the mounting sleeve is flat and perpendicular to the comparison rod.The process of reading the scale value of the ruler by passing the two ends of the comparison cable through the two ends of the measuring rod and then through the rope hole is as follows: pull the two ends of the comparison cable so that the comparison cable simultaneously abuts against the inner end face of the mounting sleeve and the circumference of the detection rod. At this time, the scale value of the scale line aligned with the comparison cable is the scale reading. The middle part of the comparison cable is fixed to the upper part of the end face of the mounting sleeve by a tension spring 16. The upper side 17 of the rope hole is an arc tangent to the inner end face of the mounting sleeve.

[0020] It also includes a slurry sampling mechanism, which comprises a sliding hole 18 disposed on the inner end face of the mounting sleeve, a sliding rod 19 slidably connected in the sliding hole, a transparent slurry storage tube 21 located inside the jacking pipe body and connected to the sliding hole through a connecting channel 20, a compression spring 22 for driving the sliding rod to move outward toward the jacking pipe section, and a connecting channel opening structure 23 for driving the sliding rod to move inward toward the jacking pipe section. The sliding rod is a ferromagnetic structure, the sliding hole is a blind hole, and the connecting channel opening structure is an electromagnet for attracting the sliding rod, the electromagnet being fixed to the inner end face of the mounting sleeve. The slurry storage tube is provided with a slurry discharge port, and the slurry discharge port is provided with a cap 24. During sampling, the sliding rod moves towards the inside of the jacking pipe section under the action of the opening structure, so that the connecting channel connects with the jacking pipe installation hole through the sliding hole. The slurry in the jacking pipe installation hole enters the slurry storage pipe. The appearance and color of the slurry are observed through the slurry storage pipe to see if they meet the requirements. Then the opening slurry pipe is closed. At this time, the sliding rod returns to its original position under the action of the compression spring, closing the connecting channel. The hole cover is removed, allowing the slurry in the slurry pipe to be discharged into the sampling pipe and taken to the laboratory for further compositional analysis. This completes one sampling. The sliding hole at one end of the outer surface of the jacking pipe section has an inner flange 25 to form a small diameter section. The sliding rod abuts against the inner flange and is limited. The end face of the sliding rod has a plug 26 that fills the small diameter section. The end face of the plug is flush with the end face of the external thread section. The end face 27 of the external thread section is flush with the outer circumferential surface of the jacking pipe section.

Claims

1. A method for testing grout thickness during pipe jacking, wherein the pipe jacking process includes excavating a pipe mounting hole for installing pipe sections using a tunneling head, then simultaneously pushing pipe sections one by one from the starting shaft to the receiving shaft into the pipe mounting hole using a jacking device, all pipe sections being joined together to form a jacking pipe, and injecting grout into the pipe mounting hole during the pipe section jacking process to form a lubrication layer to reduce the resistance during the pipe section jacking process, characterized in that... A grout thickness detection mechanism is integrated into the wall of the jacking pipe section for real-time detection. The grout thickness detection mechanism includes a mounting sleeve and a detection rod. The front end of the mounting sleeve has an external thread section, which is a solid structure. The external thread section is sealed and threadedly connected to a threaded mounting hole on the wall of the jacking pipe section. One end of the detection rod is sealed and slidably connected within the external thread section. The detection rod extends radially along the jacking pipe section, and its inner end has a scale line indicating the length of the outer end extending outwards. The mounting sleeve contains a return spring that drives the detection rod to extend outwards towards the outside of the jacking pipe section. The probe stops extending when it reaches the wall of the jacking pipe mounting hole. The method for testing the slurry thickness is as follows: During the advancement of the jacking pipe section, the probe retracts into the threaded mounting hole. The scale value L1 of the indicator structure on the mounting sleeve is read when the outer end of the probe is on the cylindrical surface of the outer circumference of the jacking pipe section. The slurry thickness is tested when the jacking pipe section stops advancing. Specifically: the constraint on the probe is released, and the probe extends under the action of the return spring. The probe stops extending when it touches the wall of the jacking pipe mounting hole. The scale value L2 of the indicator structure on the mounting sleeve is read. L2 - L1 is the slurry thickness.

2. The method for testing slurry thickness during pipe jacking according to claim 1, characterized in that, During the jacking process of the pipe section, the detection rod is retracted into the threaded mounting hole by the retraction positioning structure. The retraction positioning structure includes a positioning hole on the circumference of the detection rod and a positioning pin that is detachably connected to the inner end face of the mounting sleeve. When the positioning pin is inserted into the positioning hole, the detection rod is retracted into the threaded mounting hole.

3. The method for testing slurry thickness during pipe jacking according to claim 1, characterized in that, The inner end of the mounting sleeve is provided with a plurality of threaded rods distributed circumferentially along the mounting sleeve. The threaded rods extend axially along the mounting sleeve. Two clamping nuts are threaded onto the threaded rods. The threaded rods pass through the end ring. The inner end face of the end ring forms the inner end face of the mounting sleeve. The two clamping nuts clamp the end ring, thereby fixing the end ring onto the threaded rods. The indicating structure is installed on the end ring. When the mounting sleeve is installed onto the jacking pipe section, the position of the clamping nuts is adjusted so that when the outer end of the detection rod is located on the cylindrical surface of the outer circumferential surface of the jacking pipe section, the scale value of the aligned scale line of the indicating structure is zero.

4. The method for testing slurry thickness during pipe jacking according to claim 1, characterized in that, The indicating structure includes a comparison cable fixed in the middle to the upper part of the end face of the mounting sleeve and a rope hole located at the lower part of the end face of the mounting sleeve. The inner end face of the mounting sleeve is flat and perpendicular to the comparison rod. The two ends of the comparison cable pass through the two ends of the measuring rod and then through the rope hole. The process of reading the scale value of the ruler is as follows: pull the two ends of the comparison cable so that the comparison cable simultaneously abuts against the inner end face of the mounting sleeve and the circumference of the detection rod. At this time, the scale value of the scale line aligned by the comparison cable is the reading of the ruler.

5. The method for testing slurry thickness during pipe jacking according to claim 4, characterized in that, The middle part of the comparison cable is fixed to the upper part of the end face of the mounting sleeve by a tension spring.

6. A method for testing slurry thickness during pipe jacking according to claim 4 or 5, characterized in that, The upper side of the rope hole is an arc tangent to the inner end face of the mounting sleeve.

7. The method for testing slurry thickness during pipe jacking according to claim 1, characterized in that, The system also includes a slurry sampling mechanism. This mechanism comprises a sliding hole on the inner end face of the mounting sleeve, a sliding rod slidably connected within the sliding hole, a transparent slurry storage tube located inside the jacking pipe body and connected to the sliding hole via a connecting channel, a compression spring driving the sliding rod to move outwards towards the jacking pipe section, and a connecting channel opening structure driving the sliding rod to move inwards towards the jacking pipe section. The slurry storage tube has a slurry discharge port, and the discharge port has a cap. During sampling, the sliding rod moves inwards towards the jacking pipe section under the action of the opening structure, allowing the connecting channel to connect with the jacking pipe mounting hole via the sliding hole. Slurry from the jacking pipe mounting hole enters the slurry storage tube. The appearance and color of the slurry are observed through the storage tube to ensure it meets requirements. The opening of the slurry tube is then closed. At this point, the sliding rod returns to its original position under the action of the compression spring, closing the connecting channel. The cap is removed, allowing the slurry in the slurry tube to drain into the sampling tube, which is then taken to the laboratory for further compositional analysis, completing one sampling operation.

8. The method for testing slurry thickness during pipe jacking according to claim 7, characterized in that, The sliding hole is located on one end of the outer surface of the jacking pipe section and has an inner flange to form a small diameter section. The sliding rod abuts against the inner flange and is limited in position.

9. A method for testing slurry thickness during pipe jacking according to claim 8, characterized in that, The end face of the slide rod is provided with a plug that fills the small diameter section. The end face of the plug is flush with the end face of the external thread section, and the end face of the external thread section is flush with the outer circumferential surface of the jacking pipe section.

10. A method for testing slurry thickness during pipe jacking according to claim 7, characterized in that, The slide rod is a ferromagnetic structure, the sliding hole is a blind hole, and the opening structure of the connecting channel is an electromagnet for attracting the slide rod. The electromagnet is fixed on the inner end face of the mounting sleeve.

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