Pipe jacking mud sleeve integrity monitoring device and monitoring processing method

Abstract

The invention relates to a pipe jacking mud sleeve integrity monitoring device and a monitoring processing method, and the pipe jacking mud sleeve integrity monitoring device comprises a pear-shaped groove pre-buried in a pipe jacking pipe joint, a pre-buried steel pipe, an annular communication pipeline, a stress sheet and a check valve, and the pear-shaped groove is pre-buried in the outer surface of the pipe jacking pipe joint; the two ends of the annular communicating pipeline are oppositely connected with the inner side wall of the pear-shaped groove to form a circulating channel, the pre-buried steel pipe penetrates through the pipe jacking section from the inner surface of the pipe jacking section to the bottom of the pear-shaped groove, the check valve is installed in the pre-buried steel pipe, and high-pressure water flows into the pear-shaped groove through the check valve on the pre-buried steel pipe. The pear-shaped groove is washed, and the stress piece is embedded in the outer wall of the annular communicating pipeline and used for sensing the pressure stress of the annular communicating pipeline. According to the invention, by monitoring the pressure change after slurry circulation, the integrity of the slurry sleeve is intuitively monitored, and which ring pipe joint is lack of the slurry sleeve can be accurately judged, so that the monitoring accuracy is improved, corresponding measures can be conveniently and accurately taken in time, and the implementation process is simple and rapid.

Description

Technical Field

[0001] This invention relates to the field of pipe jacking construction technology, and in particular to a pipe jacking mud sleeve integrity monitoring device and monitoring and processing method. Background Technology

[0002] In pipe jacking construction, the mud sleeve, specifically referring to a thixotropic mud sleeve, is a lubricating film formed by injecting thixotropic mud between the outer wall of the pipe and the soil layer during pipe jacking. Its core function is to reduce jacking resistance through lubrication and temporarily support the surrounding soil to maintain the stability of the excavation face. Constructing a complete and continuous drag-reducing mud sleeve between the outer wall of the pipe section and the soil layer is crucial for controlling jacking resistance and ensuring the smooth progress of the project. Currently, monitoring the integrity of the mud sleeve mainly relies on empirical inference methods based on grouting pressure, flow rate data, and jacking force control. This method cannot perceive the actual spatial distribution of the mud in the circumferential and longitudinal directions. On-site technicians infer the resistance magnitude through jacking force and then analyze the integrity of the mud sleeve. This measure is a post-event control and is highly susceptible to excessive jacking force, leading to pipe section structural damage and tunnel quality accidents.

[0003] Due to the limited over-excavation space during pipe jacking, continuous injection of drag-reducing grout to ensure the integrity of the mud jacket would inevitably lead to surface uplift. Therefore, intermittent injection (including the initial injection volume of the new pipe section and subsequent grout replenishment) is generally used on-site. The initial injection volume is calculated based on the over-excavation volume of the new jacking pipe section, and periodic grout replenishment is performed based on experience. This method has extremely poor reliability. If there are significant changes in the characteristics of the jacking strata, the judgment of this method will be seriously flawed, the jacking resistance will increase significantly, and the jacking cost will also increase significantly (in long-distance pipe jacking, intermediate sections need to be lowered to overcome the problem of high jacking force over excessive jacking distances). Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an accurate, reliable, simple and convenient pipe jacking mud sleeve integrity monitoring device, as well as a pipe jacking mud sleeve integrity monitoring and processing method using the monitoring device.

[0005] This invention is achieved through the following technical solution: A pipe jacking slurry integrity monitoring device includes a pear-shaped groove, a pre-embedded steel pipe, an annular connecting pipe, a stress plate, and a check valve pre-embedded in a pipe jacking section. The pear-shaped groove is pre-embedded on the outer surface of the pipe jacking section. The annular connecting pipe is a thin-walled pipe pre-embedded in the pipe jacking section, with its two ends respectively connected to the inner sidewall of the pear-shaped groove to form a circulation channel. The pre-embedded steel pipe extends from the inner surface of the pipe jacking section through the pipe jacking section to the bottom of the pear-shaped groove, that is, one end of the pre-embedded steel pipe is connected to the bottom of the pear-shaped groove, and the other end extends to the inner surface of the pipe jacking section. The check valve is installed inside the pre-embedded steel pipe. High-pressure water flows through the check valve on the pre-embedded steel pipe into the pear-shaped groove to flush the pear-shaped groove. The check valve is used to prevent slurry in the pear-shaped groove from entering the pre-embedded steel pipe. The stress plate is pre-embedded on the outer wall of the annular connecting pipe to sense the compressive stress of the annular connecting pipe, and its data line is led to the interior of the pipe jacking section.

[0006] Furthermore, the annular connecting pipe is a steel pipe or a PVC pipe, and the ratio of its wall thickness t to its inner diameter D satisfies t / D≤0.1, or the ratio of its outer diameter to its inner diameter K≤1.2.

[0007] Furthermore, the check valve is provided with a connection point between a pre-embedded steel pipe and the bottom of a pear-shaped groove.

[0008] Furthermore, the opening diameter of the pear-shaped groove is 60-100mm, the bottom diameter is 80-150mm, and the depth is 100-150mm.

[0009] Furthermore, the annular connecting pipe is laid out in an arc shape without bends, and its inner diameter is 20-50mm; the inner diameter of the pre-embedded steel pipe is 30-60mm.

[0010] A method for monitoring and processing the integrity of pipe jacking mud sleeve, using the aforementioned pipe jacking mud sleeve integrity monitoring device, includes the following steps: S1. Pre-embedded device: Set pear-shaped protrusions that match the pear-shaped grooves at corresponding positions on the inner surface of the pipe section mold, lay pre-embedded steel pipes with check valves, annular connecting pipes and stress plates, pour concrete, and prefabricate the jacking pipe section. S2. Signal calibration: After the pipe jacking section is cured, each pre-embedded stress plate (sensor) is initially calibrated and its signal is tested. S3. System integration and debugging: Connect the data lines of the pre-embedded stress plates to the data acquisition module on the inner wall of the pipe section. Before the pipe section is hoisted and lowered into the well, complete the system integration and debugging of all stress plates (sensors). S4. Signal monitoring, early warning and processing: During the pipe jacking and intermittent periods, data of each stress plate is continuously or periodically collected. The pressure value of the stress plate is used to determine whether there is a risk of missing mud sleeve at the pear-shaped groove corresponding to the stress plate. If so, an early warning is issued and the injection pipe near the location of the missing risk is started to inject drag-reducing mud. At the same time, the pre-embedded steel pipe in the device corresponding to the stress plate is connected to the high-pressure water flow, and the high-pressure water flow is started to flush away the rock and soil in the pear-shaped groove. S5. Continuous monitoring: After flushing and slurry replenishment are completed, continuously monitor the pressure recovery of the device until the pressure stabilizes and returns to the normal range for a period of time. S6. After the jacking pipe is completed, the pre-embedded steel pipe is sealed.

[0011] Furthermore, in step S6, the method for sealing the pre-embedded steel pipe is as follows: sealing the inlet end of the pre-embedded steel pipe by means of plugging or welding; or, injecting quick-drying cement slurry from inside the pre-embedded steel pipe to seal the pear-shaped groove and the pre-embedded steel pipe.

[0012] Furthermore, in step S4, the method for determining whether there is a risk of missing mud sleeve at the pear-shaped groove corresponding to the stress plate by the pressure value of the stress plate is as follows: if the pressure value of a stress plate is continuously decreasing, or significantly lower than the pressure value of other stress plates on the same ring segment, or the pressure value of stress plates on adjacent segments, then it is determined that there is a risk of missing mud sleeve at that location.

[0013] Furthermore, in step S5, after completing the rinsing and grouting, the method of continuously monitoring the pressure recovery of the device until the pressure stabilizes and returns to the normal range for a period of time is as follows: if the pressure value of the stress plate is still lower than the normal range after the rinsing and grouting are completed, the high-pressure water rinsing and grouting operation in step S4 is repeated in sequence. When the pressure value of the stress plate stabilizes and returns to the normal range for a period of time (e.g., 5-10 minutes), it is determined that the mud sleeve has been repaired and the high-pressure water rinsing and grouting are stopped.

[0014] Furthermore, in step S1, for pipe jacking sections with a normal length not exceeding 1.5m, at least two sets of the aforementioned devices are pre-embedded in the axial direction, meaning that the number of pre-embedded devices has at least two projections in the axial direction. When the length of the pipe jacking section exceeds 1.5m, the number of pre-embedded monitoring devices will be increased. When the span between the upper and lower surfaces of the pipe jacking section is greater than 5m, at least two sets of the aforementioned devices are pre-embedded in the circumferential direction with a staggered arrangement, meaning that the pre-embedded devices have at least two projections in the circumferential direction (the direction perpendicular to the axis), so that all directions of the pipe section in the circumferential direction can be monitored.

[0015] The mud sleeve integrity monitoring device of this invention mainly consists of a pear-shaped groove, a pre-embedded steel pipe, an annular connecting pipe, stress plates, and a check valve. Drag-reducing mud is introduced into the mud sleeve through the pear-shaped groove, and the annular connecting pipe directly contacts the flowing drag-reducing mud, thus connecting the annular connecting pipe to the mud sleeve. The connection between the mud sleeve and the pear-shaped groove can be monitored by monitoring the compressive stress of the annular connecting pipe. When the mud sleeve is missing, the annular connecting pipe disconnects from the mud sleeve, and its compressive stress inevitably changes. Therefore, by monitoring the pressure data of the stress plate, the missing mud sleeve can be monitored in real time and intuitively, changing the ambiguous state of relying on indirect parameters such as grouting pressure and jacking force for empirical estimation, and improving the accuracy of monitoring. Furthermore, since monitoring devices are installed on each pipe section, the location of the missing mud sleeve in that pipe section can be accurately pinpointed, allowing for timely and accurate corresponding measures. Measures are taken to ensure a fast response time. The pear-shaped groove design slows down the tendency of soil and rock to enter the groove and reduces the probability of soil and rock entering the annular connecting pipe. The combined design of the pear-shaped groove and the annular connecting pipe can effectively prevent soil and rock from invading the monitoring area after the mud sleeve is missing, which would lead to inaccurate monitoring data. The stress plate is embedded in the concrete close to the outer wall of the annular connecting pipe, which is convenient to install and can avoid interference from soil and rock compression, further ensuring the accuracy of monitoring data. The entire monitoring device is pre-embedded during the pipe jacking section manufacturing process, and the installation of the device is completed during the pipe section prefabrication process. The construction process of the pipe jacking tunnel does not require the addition of other external devices and other operations, which is simple and quick. The monitoring device can detect and replenish the mud sleeve when it is missing, ensuring the integrity of the mud sleeve throughout the jacking process, which is conducive to controlling the jacking resistance and thus ensuring the maximum efficiency of jacking. Attached Figure Description

[0016] Figure 1 This is a construction structure diagram of the monitoring device according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the monitoring device according to an embodiment of the present invention.

[0018] Figure 3 This is a structural schematic diagram of the monitoring device from another perspective in an embodiment of the present invention.

[0019] Figure 4 This is a flowchart illustrating the monitoring and processing method according to an embodiment of the present invention.

[0020] Reference numerals: 1-Monitoring device; 2-Mud sleeve; 3-Missing mud sleeve; 4-Pipe section; 5-Pipe jacking machine; 11-Pear-shaped groove; 12-Annular connecting pipe; 13-Embedded steel pipe; 14-Check valve; 15-Stress plate; 16-High-pressure water flow. Detailed Implementation

[0021] A pipe jacking mud sleeve integrity monitoring device 1 is pre-embedded in the pipe jacking section 4. One or more monitoring devices 1 are pre-embedded in one pipe jacking section 4, such as... Figures 1 to 3 As shown, the pipe jacking machine 5 is located in the jacking direction. The monitoring device 1 includes a pear-shaped groove 11, a pre-embedded steel pipe 13, an annular connecting pipe 12, a stress plate 15, and a check valve 14, all pre-embedded in the pipe section 4. The pear-shaped groove 11 is pre-embedded on the outer surface of the pipe section 4, with a smaller opening at the top and a larger opening at the bottom. The smaller opening is located on the outer surface of the pipe section 4, and the bottom extends into the pipe wall of the pipe section 4. The annular connecting pipe 12 is a thin-walled pipe, pre-embedded in the pipe section 4. Its two ends are respectively connected to the inner sidewall of the pear-shaped groove 11 to form a circulation channel. The slurry flows from the pear-shaped groove 11 through the annular connecting pipe 12 and then back into the pear-shaped groove 11. The pre-embedded steel pipe 13 is also pre-embedded in the pipe section 4. Pipe 13 extends from the inner surface of the jacking pipe section 4 through the jacking pipe section 4 to the bottom of the pear-shaped groove 11. That is, one end of the pre-embedded steel pipe 13 is connected to the bottom of the pear-shaped groove 11, and the other end extends to the inner surface of the jacking pipe section 4. The check valve 14 is installed inside the pre-embedded steel pipe 13. High-pressure water flow 16 enters the pear-shaped groove 11 through the check valve 14 on the pre-embedded steel pipe 13 to flush the pear-shaped groove 11. The check valve 14 is used to prevent slurry in the pear-shaped groove 11 from entering the pre-embedded steel pipe 13. The stress plate 15 is pre-embedded in the outer wall of the annular connecting pipe 12 to sense the compressive stress of the annular connecting pipe 12. Its data line is led to the inside of the jacking pipe section 4. The check valve 14 is preferably located at the connection between the pre-embedded steel pipe 13 and the bottom of the pear-shaped groove 11.

[0022] A pear-shaped groove 11 with a small upper opening and a large lower opening is set on the surface of pipe section 4. When the mud sleeve 3 is missing, sand is not easily squeezed into the groove (especially cohesive soil). Secondly, the side of the pear-shaped groove 11 forms a slope (upward in and downward out), so sand particles are not easily dropped into the annular connecting channel and block the channel. Then, by setting up a pre-embedded steel pipe 13, the sand that enters the groove can be washed away by high-pressure water flow 16, and there will be no blockage.

[0023] By attaching stress gauges (stress sensors) to the outer wall of a pipe, the minute deformations (strain) caused by changes in internal pressure can be measured, thus indirectly obtaining the pipe's pressure value. According to the theory of thin-walled cylinders, for a cylindrical structure where the ratio of wall thickness t to inner diameter D satisfies t / D≤0.1 (or the ratio of outer diameter to inner diameter K≤1.2), the circumferential stress σ and the internal pressure P have the following relationship: σ=P·D / 2t, where D is the pipe diameter and t is the wall thickness. The strain gauge can infer the pressure change ΔP by measuring the stress change Δσ. In this invention, the annular connecting pipe 12 is connected to the pear-shaped groove 11. The opening of the pear-shaped groove 11 is located on the outer surface of the pipe section 4 and is connected to the mud sleeve 2. When the mud sleeve 2 is intact, the pear-shaped groove 11, the annular connecting pipe 12 and the mud sleeve 2 are connected, and the pressure value is stable. When the mud sleeve 3 is missing, the pear-shaped groove 11, the annular connecting pipe 12 and the mud sleeve 2 are not connected, and the pressure value changes. These changes in pressure value can all be reflected in the stress sheet 15 that is closely attached to the annular connecting pipe 12.

[0024] This invention uses a stress plate 15 embedded in concrete to sense the pressure of the drag-reducing mud flow entering the annular connecting pipe 12. This can verify the integrity of the mud sleeve 2 at that location. If the mud sleeve 2 is incomplete, the annular connecting pipe 12 is not connected to the mud sleeve, and even if the groove is filled with soil, it will be difficult to enter the pipe. The stress plate 15 will sense the stress change of the annular connecting pipe 12. When the stress change exceeds a certain range, it can be determined that the mud sleeve 3 is missing at that location, and the annular pipe section 4 needs to be grouted. After grouting for a period of time, high-pressure water is used to flush away the soil filled in the groove. The drag-reducing mud after grouting is reconnected to the annular connecting pipe 12 through the pear-shaped groove 11. The stress plate 15 re-acquires the stress of the annular connecting pipe 12 and continuously monitors the stress of the annular connecting pipe 12.

[0025] In one embodiment, the annular connecting pipe 12 is a steel pipe or a PVC pipe, with the ratio of its wall thickness t to its inner diameter D satisfying t / D≤0.1, or the ratio of its outer diameter to its inner diameter K≤1.2. To more accurately measure the strain of the annular connecting pipe 12 and reflect the pressure value inside the pipe, the annular connecting pipe 12 is arranged in an arc shape without bends, and its inner diameter is 20-50mm. The inner diameter of the pre-embedded steel pipe 13 is 30-60mm, preferably 50mm.

[0026] In some embodiments, the pear-shaped groove 11 has an opening diameter of 50-100 mm, a bottom diameter of 80-150 mm, and a depth of 100-150 mm. Preferably, the pear-shaped groove 11 has an opening diameter of 80 mm, a bottom diameter of 100 mm, and a depth of 120 mm.

[0027] A method for monitoring and handling the integrity of the pipe jacking mud sleeve, using the aforementioned pipe jacking mud sleeve integrity monitoring device 1, such as... Figure 4The monitoring and processing method includes the following steps: S1. Device pre-embedding: Pear-shaped protrusions that match the pear-shaped groove 11 are set at corresponding positions on the inner surface of the pipe section mold. Pre-embedded steel pipe 13 with check valve 14, annular connecting pipe 12 and stress plate 15 are arranged. Concrete is poured and the jacking pipe section 4 is prefabricated. After the pear-shaped protrusion concrete is poured, the pear-shaped groove 11 is formed.

[0028] The embedded steel pipe 13 is a straight pipe, and the ring connecting pipe 12 is a curved pipe, which are staggered in the concrete of pipe section 4.

[0029] Pipe section 4 can be circular or rectangular, and the device is pre-embedded around the perimeter of pipe section 4. For pipe sections with a normal length not exceeding 1.5m, at least two sets of the aforementioned device are pre-embedded in the axial direction, meaning that the number of pre-embedded devices has at least two projections in the axial direction. When the length of pipe section 4 exceeds 1.5m, the number of pre-embedded monitoring devices should be increased, such as four or six sets, depending on the specific length of the pipe section and the project requirements. The devices are preferably staggered in the lateral direction. When the span between the upper and lower surfaces of pipe section 4 is greater than 5m, at least two sets of the aforementioned device are pre-embedded in the circumferential direction with staggered placement, meaning that the pre-embedded devices have at least two projections in the circumferential direction (perpendicular to the axis), so that all directions of the pipe section in the circumferential direction can be monitored.

[0030] S2. Signal calibration: After the jacking pipe section 4 is cured, each pre-embedded stress plate 15 (sensor) is initially calibrated and signal tested.

[0031] S3. System integration and debugging: Connect the data lines of the pre-embedded stress plates 15 to the data acquisition module on the inner wall of the pipe section 4. Before the pipe section 4 is hoisted into the well, complete the system integration and debugging of all stress plates 15 (sensors).

[0032] S4. Signal monitoring, early warning and processing: During the pipe jacking and intermittent periods, data of each stress plate 15 is continuously or periodically collected. The pressure value of the stress plate 15 is used to determine whether there is a risk of missing mud sleeve 2 at the pear-shaped groove 11 corresponding to the stress plate 15. If so, an early warning is issued and the injection pipe near the location of the missing risk is started to inject drag-reducing mud. At the same time, the pre-embedded steel pipe 13 in the device corresponding to the stress plate 15 is connected to the high-pressure water flow 16, and the high-pressure water flow 16 is started to flush away the rock and soil in the pear-shaped groove 11.

[0033] During pipe jacking, the cross-section of the excavated cavity by the pipe jacking machine 5 is larger than the cross-section of the pipe tunnel, resulting in over-excavation space. A special grout is used to form a mud sleeve 2 to reduce drag and support the upper soil (after grouting, the pipe tunnel is essentially suspended in the grout, significantly reducing resistance). The grout flows into the annular connecting pipe 12 in the device. The pressure inside the annular connecting pipe 12 is connected to the mud sleeve 2, generating pressure. The stress plate 15 embedded in the concrete monitors this pressure data. When the mud sleeve 3 is missing, the pipe tunnel will directly contact the rock and soil surface, significantly increasing resistance. The pear-shaped groove 11 in the device will directly contact the rock and soil surface without grout flow, causing the annular connecting pipe 12 to disconnect from the mud sleeve due to loss of connection. Furthermore, the pear-shaped design makes it difficult for rock and soil to enter the annular connecting pipe 12, inevitably causing a change in pressure within the annular connecting pipe 12. The stress plate 15, which is closely attached to the annular connecting pipe 12, will inevitably sense this abnormal change in pressure data.

[0034] The method for determining whether there is a risk of missing mud sleeve 2 is as follows: if the pressure value of a certain stress plate 15 is continuously decreasing, or significantly lower than the pressure value of other stress plates 15 on the same ring segment, or the pressure value of stress plates 15 on adjacent segments, then it is determined that there is a risk of missing mud sleeve 2 at that location.

[0035] During pipe jacking, there are three main situations that can lead to a missing mud sleeve: (1) Insufficient injection of drag-reducing mud around the newly entered pipe section, resulting in the mud failing to cover the pipe circumference. In this case, the monitoring device (stress gauge) cannot detect the pressure from the outset; (2) During the pipe excavation process, water seeps into the stratum from the mud, causing the mud to lose water and gradually form a mud film that adheres to the stratum or replenish the drag-reducing mud around the newly entered pipe section. This reduces the amount of mud (volume decreases) and lowers the pressure. If there is no additional grouting, mud will be missing in some areas around the pipe. In this case, looking at the pear-shaped groove at the missing location, it means that the mud is "interrupted" from the mud inside the pear-shaped groove. The mud inside the pear-shaped groove is not connected to the external mud sleeve. From the fluid pressure characteristics (fluid pressure depends on fluid conduction), It is said that the pressure brought by the mud sleeve will not be detected at this point, which will cause the data monitored by the stress plate to be abnormal, generally continuously decreasing; (3) the pipe is offset from the axis or the pipe is curved, and one side of the pipe is in direct contact with the stratum, resulting in the absence of the mud sleeve. Since the soil layer cut by the cutterhead is bound to be uneven, when it comes into contact with the stratum, the mud sleeve at this point will be cut off. In this case, the slurry in the groove will be lost on the uneven stratum, and the stress plate will detect the pressure reduction or absence immediately. Or the soil layer just completely covers the groove surface. Also, because of the pear-shaped structure, the groove will not be filled with soil particles immediately. The slurry in the channel will still be lost, and the pressure will decrease. Even if the groove is just completely filled, the water in the slurry in the pipe will seep into the stratum, causing the pressure to drop. In addition, the pipe is in the continuous tunneling process, that is, the pipe cannot be in contact with the stratum all the time. Once it is separated, the pressure will also drop sharply. It is evident that, regardless of the situation described above, as long as the mud sleeve is missing, the annular connecting pipe in the corresponding monitoring device will be disconnected from the mud sleeve, its pressure value will decrease, and an anomaly will occur. The stress plate adjacent to it will inevitably sense the pressure change in the annular connecting pipe and thus respond in a timely manner.

[0036] S5. Continuous monitoring: After rinsing and slurry replenishment are completed, continuously monitor the pressure recovery of the device until the pressure stabilizes and returns to the normal range for a period of time.

[0037] Specifically, if the pressure value of the stress plate 15 is still below the normal range after rinsing and grouting, the high-pressure water flow 16 rinsing and grouting operation in step S4 is repeated. When the pressure value of the stress plate 15 stabilizes and returns to the normal range and remains there for a period of time (e.g., 5-10 minutes), it is determined that the mud sleeve 2 has been repaired and the high-pressure water flow 16 rinsing and grouting are stopped.

[0038] S6. After the jacking pipe is completed, seal the pre-embedded steel pipe 13. Specifically, the inlet end of the pre-embedded steel pipe 13 can be sealed by plugging or welding; or, quick-drying cement grout can be injected into the pre-embedded steel pipe 13 to seal the pear-shaped groove 11 and the pre-embedded steel pipe 13.

[0039] The above detailed description is a specific description of feasible embodiments of the present invention. These embodiments are not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included in the patent scope of this case.

Claims

1. A device for monitoring the integrity of pipe jacking mud sleeve, characterized in that, The device comprises a pear-shaped recess pre-embedded in a pipe section of the pipe, a pre-embedded steel pipe, an annular communication pipeline, a stress sheet and a check valve. The pear-shaped recess is pre-embedded on the outer surface of the pipe section. The annular communication pipeline is a thin-walled pipeline, which is pre-embedded in the pipe section and connected to the inner side wall of the pear-shaped recess at opposite ends to form a circulation channel. The pre-embedded steel pipe penetrates the pipe section from the inner surface of the pipe section to the bottom of the pear-shaped recess. The check valve is installed in the pre-embedded steel pipe. High-pressure water flows through the check valve on the pre-embedded steel pipe into the pear-shaped recess to flush the pear-shaped recess. The check valve is used to prevent the slurry in the pear-shaped recess from entering the pre-embedded steel pipe. The stress sheet is pre-embedded at the outer wall of the annular communication pipeline to sense the compressive stress of the annular communication pipeline.

2. The device for monitoring the integrity of a pipe jacking slurry according to claim 1, wherein, The annular communication pipeline is a steel pipeline or a PVC pipeline, and the ratio of the wall thickness t to the inner diameter D satisfies t / D≤0.1, or the ratio of the outer diameter to the inner diameter K≤1.

2.

3. The device for monitoring the integrity of a pipe jacking slurry according to claim 1, wherein, The check valve is arranged at the connection between the pre-embedded steel pipe and the bottom of the pear-shaped recess.

4. The device for monitoring the integrity of a pipe jacking slurry according to claim 1, wherein, The opening diameter of the pear-shaped recess is 60-100 mm, the bottom diameter is 80-150 mm, and the depth is 100-150 mm.

5. The device for monitoring the integrity of a pipe jacking slurry according to claim 1, wherein, The annular communication pipeline is arranged in an arc shape without bending, and the inner diameter is 20-50 mm. The inner diameter of the pre-embedded steel pipe is 30-60 mm.

6. A method for monitoring and processing the integrity of the pipe jacking mud sleeve, characterized in that, The monitoring method comprises the following steps: S1, device pre-embedding: a pear-shaped protrusion matching the pear-shaped recess is arranged at the corresponding position of the inner surface of the pipe section mold, the pre-embedded steel pipe with a check valve, the annular communication pipeline and the stress sheet are arranged, and the pipe section is precast by pouring concrete; S2, signal calibration: after the pipe section is maintained, the initial calibration and signal test of each pre-embedded stress sheet are performed; S3, system commissioning: the data line of the pre-embedded stress sheet is connected to the data acquisition module on the inner wall of the pipe section, and the system commissioning of all stress sheets is completed before the pipe section is hoisted into the well; S4, signal monitoring, early warning and processing: during pipe jacking and intermittent period, the data of each stress sheet is continuously or periodically collected, and whether the mud sleeve at the pear-shaped recess corresponding to the stress sheet has a missing risk is judged according to the pressure value of the stress sheet. If yes, an early warning is issued, and the pre-embedded steel pipe in the device is connected to a high-pressure water flow to start the high-pressure water flow to flush away the rock-soil in the pear-shaped recess; S5, continuous monitoring: after flushing and grouting are completed, the pressure recovery of the device is continuously monitored until the pressure is stably recovered to the normal range and maintained for a period of time; S6, sealing the pre-embedded steel pipe after the pipe is penetrated.

7. The method of integrity monitoring of a pipe jacking slurry according to claim 6, wherein, In the step S6, the method for sealing the pre-embedded steel pipe is to seal the inlet end of the pre-embedded steel pipe in the form of a plug or welding, or to seal the pear-shaped recess and the pre-embedded steel pipe by injecting a quick-drying cement slurry from the pre-embedded steel pipe.

8. The method of claim 6, wherein the method further comprises, In the S4 step, the method for judging whether the mud cake at the pear-shaped groove corresponding to the stress piece has a missing risk according to the pressure value of the stress piece is: if the pressure value of a stress piece is continuously reduced, or is significantly lower than the pressure values of other stress pieces on the same ring piece or the pressure values of stress pieces on adjacent ring pieces, it is determined that the mud cake at the position has a missing risk.

9. The method of claim 6, wherein the method further comprises, In the S5 step, after the flushing and mud supplementing are completed, the pressure recovery of the device is continuously monitored until the pressure is stably recovered to the normal range and remains for a period of time. The method is: if the pressure value of the stress piece is still lower than the normal range after the flushing and mud supplementing are completed, the high-pressure water flushing and mud supplementing operations in the S4 step are repeatedly performed. When the pressure value of the stress piece is stably recovered to the normal range and remains for a period of time, it is determined that the mud cake at the position has been repaired and the high-pressure water flushing and mud supplementing are stopped.

10. The method of claim 6, wherein the method further comprises, In the S1 step, for a pipe jacking pipe section with a length of not more than 1.5 m, at least two sets of the device are pre-embedded in the axial direction, that is, the number of pre-embedded devices has at least two projections in the axial direction. When the length of the pipe jacking pipe section exceeds 1.5 m, the number of pre-embedded devices is increased. When the span of the upper outer surface and the lower outer surface of the pipe jacking pipe is greater than 5 m, at least two sets of the device are pre-embedded in the ring direction with a staggered arrangement.

Images