Large-diameter water supply and drainage pipeline connection anti-seepage method

Abstract

The invention provides a large-diameter water supply and drainage pipeline connection anti-seepage method. The method comprises the following steps that 1, a laser contourgraph is adopted to scan a pipeline connecting end face, microstructure regulation and control are conducted on the connecting end face through grinding equipment according to the scanning result, the roughness Ra of the end face is smaller than or equal to 0.8 micrometer, an annular sealing groove is formed, and the width of the groove is 1 / 5-1 / 4 of the wall thickness of a pipeline; 2, selecting a temperature-adaptive elastic sealing element, embedding the sealing element into the annular sealing groove, adjusting the axis deviation of the two pipelines to be less than or equal to 0.5 mm / m through hydraulic pushing equipment, and meanwhile, applying 3-5% of pre-compression amount to the sealing element; 3, the circumferential contact pressure of the sealing element is detected through a pressure sensor array, it is ensured that the pressure fluctuation is smaller than or equal to 5%, and if the pressure is abnormal, secondary calibration is conducted through pushing equipment; according to the method, the problem of synergism deficiency of all construction links can be solved, the hidden danger of micro-leakage is eliminated, and long-term stability of the anti-seepage effect is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline anti-seepage, in particular to a large-diameter water supply and drainage pipeline connection anti-seepage method. BACKGROUND

[0002] In the construction of large-diameter water supply and drainage pipeline engineering, the anti-seepage performance of the pipeline connection part directly determines the operation reliability and service life of the overall pipeline system. The current industry conventional construction process includes pipeline connection end face processing, sealing element assembly, interface fixation, backfill protection, and leakage detection. However, the existing technology has significant shortcomings in practical application. Specifically, the traditional end face processing relies on manual polishing or simple mechanical grinding, which is difficult to accurately control the micro roughness and morphology consistency of the end face. Sealing gaps are often formed due to micro scratches and unevenness on the end face. During sealing element assembly, the influence of temperature changes on the elasticity of the sealing element and the dynamic adjustment of the pipeline axis deviation are not fully considered, which easily leads to local overpressure or underpressure of the sealing element. The sealing pressure monitoring is mostly in a single-point detection mode, which cannot cover the entire range of the interface circumference and is difficult to find the weak points of the sealing caused by local pressure fluctuations. The subsequent backfill protection does not design a buffer structure according to the stress characteristics of the interface, which easily leads to interface deformation and damage to the sealing structure due to uneven compaction of backfill soil or external load impact. The lack of coordination between the above-mentioned links makes the pipeline connection part prone to early micro-leakage, which is difficult to detect in the early stage and will gradually intensify pipeline corrosion and interface structure aging during long-term operation, eventually leading to serious leakage accidents, which not only increases the maintenance cost, but also may pollute the surrounding soil and groundwater environment.

[0003] Based on the above problems, there is an urgent need for a large-diameter water supply and drainage pipeline connection anti-seepage technology that can solve the lack of coordination between the construction links, eliminate micro-leakage hazards, and ensure long-term stability of the anti-seepage effect. SUMMARY

[0004] The purpose of the present application is to solve the shortcomings in the prior art and to provide a large-diameter water supply and drainage pipeline connection anti-seepage method, which comprises the following steps: Step 1: use a laser profilometer to scan the pipeline connection end face, and according to the scanning results, use a grinding device to control the micro-morphology of the connection end face, so that the end face roughness Ra is less than or equal to 0.8 microns and an annular sealing groove is formed, and the groove width is 1 / 5-1 / 4 of the pipeline wall thickness; Step 2: select a temperature-adaptive elastic sealing element, embed the sealing element in the annular sealing groove, adjust the axis deviation of the two pipelines to less than or equal to 0.5 mm / m through a hydraulic pushing device, and at the same time, apply a pre-compression amount of 3%-5% to the sealing element; Step 3: Detect the circumferential contact pressure of the sealing element using a pressure sensor array to ensure that the pressure fluctuation is ≤5%, and if the pressure is abnormal, then the push equipment is calibrated again; Step 4: Wrap an elastic buffer layer with a thickness of 10-15mm outside the pipeline interface, and then perform layered backfilling, with the compaction degree of each layer of backfilling material being ≥95%; Step 5: Perform pressure maintaining detection on the interface using water pressure leakage detection equipment, with the pressure maintaining pressure being 1.2 times the design working pressure of the pipeline, and the pressure maintaining time being ≥30min. During the detection process, the leakage amount is monitored through a flow sensor, and the leakage amount ≤0.01L / (m·h) is determined to be qualified.

[0005] Preferably, the rotation speed of the grinding head of the grinding equipment in step 1 is 800-1200r / min, and an aqueous grinding liquid is used during the grinding process, with the abrasive particle size in the grinding liquid being 10-20μm.

[0006] Further preferably, the temperature-adaptive elastic sealing element in step 2 is made of ethylene-propylene-diene rubber, and a metal reinforcing framework is embedded inside the sealing element, with the difference between the linear expansion coefficients of the metal reinforcing framework and the pipeline material being ≤1×10 -6 / ℃.

[0007] Further preferably, the pushing force of the hydraulic pushing equipment in step 2 is controlled to be 50-80kN, and the axial deviation is monitored in real time through a laser collimator during the pushing process, with the deviation value being recorded every 5mm of pushing.

[0008] Further preferably, the sensor spacing of the pressure sensor array in step 3 is 20-30mm, the measurement accuracy of the sensor is ±0.1kPa, and the pressure detection data is transmitted in real time to the control terminal through a wireless transmission module.

[0009] Further preferably, before the sealing element is embedded in the annular sealing groove in step 2, a step of brushing a silane coupling agent on the inner wall of the sealing groove is further included, with the brushing thickness of the silane coupling agent being 0.1-0.2mm, and the brushing is left to stand for 5-10min after brushing.

[0010] Further preferably, the thickness of each layer of the layered backfilling in step 4 is 200-300mm, the backfilling material is graded sand and gravel, the sand and gravel particle size range is 5-20mm, and 3%-5% of bentonite is mixed into the backfilling material.

[0011] Further preferably, the elastic buffer layer in step 4 is made of nitrile rubber, an epoxy adhesive is brushed on the inside of the buffer layer, the adhesive bonding strength is ≥2.5MPa, the buffer layer is fixed outside the pipeline interface through stainless steel clamps, and the clamp spacing is 150-200mm.

[0012] It is further preferred that in the pressure maintaining detection process in step 5, the pressure value and the leakage amount are recorded once every 5 minutes, and if the pressure drops by 0.05 MPa or more or the leakage amount exceeds the limited value, the pressure maintaining is stopped and steps 2-3 are re-executed.

[0013] It is further preferred that in step 1, the scanning accuracy of the laser profilometer is ±0.01 mm, and the scanning range covers the entire pipe connecting end face, and the scanning data is used to generate an end face topography three-dimensional model through a data analysis module, and the model is used to determine the grinding area and the grinding amount.

[0014] Technical effects: The present application solves the core problem of isolated control in each construction link in the background technology through the synergistic technical design of end face microtopography regulation, temperature adaptation sealing, axis precise adjustment, pressure sensor array monitoring, elastic buffering, high pressure real backfilling and strict pressure maintaining detection.

[0015] The creativity lies in integrating the dispersed links into a closed anti-seepage system: precise grinding of the end face eliminates the sealing gap, adaptive sealing and axis control avoid local failure, full-circle pressure monitoring identifies weak points, buffering backfilling resists external damage, strict detection captures micro leakage, finally eliminates early micro leakage hidden dangers, ensures long-term stability of the anti-seepage effect of the pipe connection, and reduces the maintenance cost and environmental risk in the later period. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The present application is a large-diameter water supply and drainage pipe connection anti-seepage method flow chart. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0018] The traditional technical scheme has the following technical problems: in the large-diameter water supply and drainage pipe connection anti-seepage construction, the traditional method only relies on manual polishing for the treatment of the pipe connecting end face, and cannot accurately control the microtopography of the end face, so the roughness often exceeds 1.5 μm, resulting in that the sealing element and the end face are not tightly fitted; the temperature adaptability is not considered in the selection of the sealing element, and the pipe axis deviation control is mostly based on experience, and the deviation often exceeds 1 mm / m, and there is no standard for the pre-compression amount of the sealing element, so local overpressure or underpressure often occurs; the sealing pressure detection mostly uses single-point detection, which has a monitoring blind area and cannot find the area where the circumferential pressure fluctuation exceeds 10%; there is no targeted protection outside the interface, and the interface is easily damaged due to insufficient compaction or lack of buffering structure during backfilling; the pressure maintaining pressure for leakage detection is mostly 1 times the design pressure, the pressure maintaining time is less than 20 minutes, and the leakage amount determination standard is loose, so it is difficult to find micro leakage hidden dangers.

[0019] Based on this, please refer to Figure 1 The embodiment provides a large-diameter water supply and drainage pipeline connection anti-seepage method, which comprises the following steps: Step 1: scanning the pipeline connection end face by using a laser profiler, and controlling the micro-morphology of the connection end face by using a grinding device according to the scanning result, so that the end face roughness Ra is less than or equal to 0.8 microns and an annular sealing groove is formed, and the groove width is 1 / 5-1 / 4 of the pipeline wall thickness; Step 2: selecting a temperature-adaptive elastic sealing element, embedding the sealing element into the annular sealing groove, adjusting the axis deviation of the two pipelines to be less than or equal to 0.5 mm / m by using a hydraulic pushing device, and simultaneously applying a pre-compression amount of 3%-5% to the sealing element; Step 3: detecting the circumferential contact pressure of the sealing element by using a pressure sensor array, ensuring that the pressure fluctuation is less than or equal to 5%, and if the pressure is abnormal, the pushing device is calibrated again; Step 4: wrapping an elastic buffer layer outside the pipeline interface, the buffer layer thickness is 10-15 mm, and then performing layered backfilling, and the compaction degree of each layer of backfilling material is greater than or equal to 95%; Step 5: using a water pressure leakage detection device to detect the interface, the pressure holding pressure is 1.2 times the design working pressure of the pipeline, the pressure holding time is greater than or equal to 30 minutes, and the leakage amount is monitored by a flow sensor during the detection process, and the leakage amount is determined to be qualified.

[0020] The scheme forms a closed-loop prevention and control from five aspects of end face processing, sealing adaptation, pressure monitoring, interface protection and leakage verification: the micro-morphology control of the end face provides a flat and close-fitting basis for sealing through laser scanning and accurate grinding, avoiding sealing gaps caused by rough end face; the temperature-adaptive sealing element, the accurate axis control and the pre-compression amount setting ensure that the sealing element can closely fit with the pipeline under different temperature environments and eliminate local sealing failure caused by axis deviation; the pressure sensor array realizes full coverage monitoring of the circumferential pressure, discovers and calibrates the pressure abnormal area in time, and avoids the blind area problem of single-point detection; the elastic buffer layer and the high-compaction layered backfilling can buffer the impact of backfill soil pressure and external load on the interface, prevent the interface from being damaged due to stress deformation and destroying the sealing structure; the pressure holding detection higher than the design pressure and the strict leakage amount standard can accurately capture micro-leakage and eliminate the hidden danger of missed judgment in traditional detection.

[0021] It is worth mentioning that: the application of laser profiler realizes the visual control of the end face morphology, and the annular sealing groove can limit the sealing element to avoid displacement under pressure; the temperature adaptive sealing element can adapt to different regional seasonal temperature changes, and the metal reinforcing skeleton further improves the structural stability of the sealing element; the layout density of the pressure sensor array can be adjusted according to the diameter of the pipeline to ensure that there is no dead angle in monitoring; the material selection and thickness design of the elastic buffer layer need to be determined in combination with the pipeline burial depth and the type of backfill soil, and the compaction degree control of layered backfill needs to be matched with the rolling times and intensity of the compaction equipment; during the pressure maintaining detection process, the accuracy of the flow sensor needs to match the leakage standard to ensure that small leakage can be accurately captured.

[0022] The technical effects achieved by the above technical scheme include: precise control of end face roughness and design of annular sealing groove to increase the bonding area of the sealing element and the end face, reduce the leakage channel caused by the sealing gap; precise control of axis deviation and pre-compression to ensure uniform circumferential stress of the sealing element and avoid local sealing failure; real-time monitoring and secondary calibration of the pressure sensor array to ensure that the sealing pressure is always within the effective range and improve the sealing reliability; elastic buffer layer and high compaction backfill to enhance the interface's resistance to external force interference and prolong the interface's anti-seepage life; strict pressure maintaining detection and leakage determination to ensure that the interface's anti-seepage performance meets the standard and avoid pipeline corrosion or surrounding environment damage caused by micro-leakage during later operation. The technical features of each link interact with each other, from the construction source to the effect verification, to comprehensively prevent and control the leakage risk, solving the problems of poor anti-seepage effect and short life caused by the lack of multi-link control in traditional construction.

[0023] The traditional technical scheme has the following technical problems: in the grinding construction of the large-diameter water supply and drainage pipeline connecting end face, the rotating speed of the grinding head of the traditional grinding equipment has no clear standard, which often leads to low grinding efficiency and poor end face flatness due to low rotating speed, or end face overheating damage caused by high rotating speed; oily grinding fluid is often used in the grinding process, which is easy to leave oil stains on the end face, affecting the bonding performance of the subsequent sealing element and the end face, and the oily grinding fluid has poor environmental protection; the abrasive particle size is selected randomly, and a particle size that is too large is easy to leave scratches on the end face, and a particle size that is too small leads to a long grinding period, which cannot stably meet the design requirements of the end face roughness, thereby affecting the subsequent sealing effect.

[0024] Based on this, the rotating speed of the grinding head of the grinding equipment in step 1 of the embodiment is 800-1200r / min, and water-based grinding fluid is used in the grinding process, and the abrasive particle size in the grinding fluid is 10-20μm.

[0025] The scheme solves the end face quality problem caused by parameter confusion in traditional grinding construction by accurately limiting the core parameters of the grinding equipment: the grinding head speed is controlled in the range of 800-1200 r / min, which is verified by practice to ensure sufficient grinding efficiency and quickly remove the end face processing marks, and to avoid end face overheating caused by high speed and prevent the performance change of the end face material due to high temperature; the water-based grinding fluid replaces the traditional oil-based grinding fluid, which not only has no oil stains and can ensure good adhesion of the subsequent sealing member and the end face, but also is environmentally friendly and pollution-free, meeting the environmental protection requirements of construction environment; the selection of abrasive particle size of 10-20 μm can effectively polish the end face to make the roughness stable to meet the requirement of Ra≤0.8 μm, and also can avoid scratches on the end face caused by too large particle size, avoid the formation of new leakage channels, and take into account the grinding efficiency to avoid the delay of the construction period caused by too small particle size.

[0026] It is worth mentioning that: the grinding head speed needs to be adjusted according to the pipe material, for pipes with low hardness such as cast iron, the speed can be controlled in the range of 800-1000 r / min to avoid excessive wear of the material; for pipes with high hardness such as steel pipes, the speed can be increased to 1000-1200 r / min to ensure the grinding effect; the water-based grinding fluid needs to have good cooling performance to avoid abrasive failure caused by frictional heat during grinding; the abrasive needs to be made of high hardness and wear-resistant material such as silicon carbide abrasive to ensure stable particle size during grinding and not to be affected by wear to reduce the particle size and affect the grinding effect; the supply amount of grinding fluid needs to be controlled during grinding to ensure that the abrasive can be evenly distributed between the grinding head and the end face, and to avoid uneven grinding caused by local lack of liquid.

[0027] The technical effects achieved by the above technical scheme include: accurate grinding head speed control to stabilize the end face grinding quality and avoid end face damage or incomplete grinding caused by improper speed to provide a high-quality end face basis for subsequent sealing; the application of water-based grinding fluid eliminates the influence of oil stains on sealing effect and reduces the environmental pollution caused by construction, meeting the requirements of green construction; the use of abrasive with specific particle size ensures that the end face roughness is stable and meets the requirements without scratches and other defects, avoiding sealing failure caused by end face quality problems; the synergistic effect of the three greatly improves the controllability of the grinding process, reduces the rework caused by improper grinding parameters, improves the construction efficiency, and lays a reliable end face foundation for the entire pipeline connection anti-seepage system to ensure that the subsequent sealing steps can fully play a role.

[0028] The traditional technical solution has the following technical problems: the sealing element for connecting large-diameter water supply and drainage pipelines only pays attention to hardness and elasticity in traditional selection, without considering temperature adaptability, and is prone to aging deformation in high-temperature environments, such as ground surface temperature exceeding 40°C in summer, and brittle fracture in low-temperature environments, such as below -10°C in winter, resulting in failure of sealing performance; the sealing element is mostly made of pure rubber material without a reinforcing structure, and is prone to permanent deformation under the action of long-term water pressure and external load, and cannot maintain stable sealing pressure; the linear expansion coefficient difference between the sealing element and the pipeline material is more than 3×10 -6 / ℃, and the deformation amounts of the two are not synchronized when the temperature changes, which is prone to cause leakage, especially in areas with large diurnal temperature difference or seasonal alternation.

[0029] Therefore, in step 2 of the embodiment, the temperature-adaptive elastic sealing element is made of ethylene-propylene-diene rubber material, and a metal reinforcing framework is embedded in the sealing element, and the linear expansion coefficient difference between the metal reinforcing framework and the pipeline material is less than or equal to 1×10 -6 / ℃.

[0030] The scheme solves the defects of the traditional sealing element in temperature adaptability, structural stability and deformation synchronization through material selection, structure reinforcement and expansion coefficient matching: the ethylene-propylene-diene rubber material has excellent high and low temperature resistance, and can maintain good elasticity and sealing performance in an environment of -40°C to 80°C, avoiding the aging or brittle fracture problems of traditional rubber sealing elements in extreme temperatures; the embedded metal reinforcing framework can provide structural support for the sealing element to resist permanent deformation under the action of long-term water pressure and external load, ensure that the sealing element always maintains the designed shape and pre-compression amount, and maintains stable sealing pressure; the precise matching of the linear expansion coefficients of the metal reinforcing framework and the pipeline material can ensure that the deformation amounts of the sealing element and the pipeline are basically consistent when the temperature changes, avoiding the generation of gaps due to asynchronous deformation, and fundamentally solving the leakage problem caused by temperature.

[0031] It is worth mentioning that: the formula of ethylene-propylene-diene rubber needs to be further optimized, and anti-aging agents and toughening agents can be added to improve its long-term weather resistance and tear resistance; the material of the metal reinforcing framework needs to be selected according to the material of the pipeline, such as ductile cast iron for the framework when the pipeline is made of ductile cast iron, and low-carbon steel for the framework when the pipeline is made of steel pipe, to ensure the matching of the expansion coefficients; the shape of the framework needs to be designed to match the structure of the sealing element, such as a ring-shaped framework embedded in the middle of the sealing element, which does not affect the elastic deformation of the sealing element and can provide effective support; during the production of the sealing element, the combination of the framework and the rubber needs to be ensured to be tight without delamination, to avoid displacement of the framework during use and cause failure of the sealing element.

[0032] The technical effects achieved by the above technical scheme include: the ethylene propylene diene rubber material enables the sealing element to have a wide temperature adaptation range, can be stably used in different climate regions, avoids sealing failure caused by temperature changes, and prolongs the service life of the sealing element; the metal reinforcing framework effectively improves the structural stability of the sealing element, resists permanent deformation, ensures long-term stability of the sealing pressure, and reduces the frequency of later maintenance; the precise matching of the expansion coefficients eliminates the gap caused by temperature deformation differences, and solves the temperature-related leakage problem from the root, especially suitable for areas with large diurnal temperature difference or obvious seasonal alternation; the combination of the three greatly improves the comprehensive performance of the sealing element, which not only can cope with normal working conditions, but also can adapt to extreme temperatures and long-term loads, providing reliable sealing protection for pipeline connection anti-seepage, and solving the problems of short service life and poor adaptability of traditional sealing elements.

[0033] The traditional technical scheme has the following technical problems: in the hydraulic jacking butt joint construction of large-diameter water supply and drainage pipelines, the jacking force of the traditional jacking equipment has no clear control range, and the pipeline cannot be accurately butt jointed due to too small jacking force, which needs to be adjusted repeatedly, and too large jacking force is easy to cause damage to the pipeline end face or excessive compression deformation of the sealing element, affecting the sealing performance; during the jacking process, the axis deviation is monitored by manual visual observation or long interval measurement, which cannot capture the deviation change in real time, and is easy to cause deviation accumulation out of tolerance, which is difficult to adjust later; the deviation record has no standard interval, the data is incomplete, the deviation change process cannot be traced, which is not conducive to subsequent problem analysis and process optimization, and the cost of rework after exceeding the tolerance is high and the construction period is delayed.

[0034] Based on this, the jacking force of the hydraulic jacking equipment in step 2 of the embodiment is controlled in the range of 50-80kN, and the axis deviation is monitored in real time by a laser collimator during the jacking process, and the deviation value is recorded once every 5mm of jacking.

[0035] This scheme solves the problems of parameter out of control and deviation monitoring lag in traditional jacking construction through precise control of jacking force and real-time monitoring of axis deviation and high-frequency recording: the jacking force is controlled in the range of 50-80kN, which is determined according to the structural strength of the large-diameter pipeline and the compression requirement of the sealing element, which can provide enough jacking force to realize accurate butt joint of the pipeline, and can avoid damage to the pipeline and excessive deformation of the sealing element caused by too large jacking force, ensuring the safety and controllability of the butt joint process; the laser collimator has high precision and real-time characteristics, and can monitor the axis deviation during the jacking process, avoiding the subjectivity and lag of manual observation, and discovering the deviation trend in time; the deviation value is recorded once every 5mm of jacking, and high-frequency recording ensures that the deviation data is complete, which can track the deviation change in real time, and once the deviation approaches the limit value of 0.5mm / m, the jacking can be stopped immediately and adjusted, avoiding deviation accumulation out of tolerance, and the complete data also provides a basis for subsequent construction process optimization.

[0036] It is worth mentioning that: the pushing force needs to be adjusted according to the diameter and weight of the pipeline, the pushing force of the pipeline with larger diameter and heavier weight can be controlled within 70-80kN, and the pushing force of the pipeline with smaller diameter and lighter weight can be controlled within 50-70kN, to ensure that the pushing force matches the requirements of the pipeline; the laser collimator needs to be calibrated before pushing, to ensure the measurement accuracy, and the installation position of the instrument needs to be stable to avoid vibration affecting the measurement results; the pipeline end face fitting needs to be observed synchronously during the pushing process, if abnormal sound or end face misalignment occurs, the pushing needs to be stopped immediately and the reason needs to be checked; the deviation record needs to be recorded in an electronic way for data storage and subsequent analysis, when the deviation value exceeds 0.3mm / m for two consecutive times, the adjustment needs to be made in advance to avoid approaching the limit value; the pushing equipment needs to be equipped with a pressure feedback device to display the pushing force in real time to ensure that the pushing force is within the set range.

[0037] The technical effects achieved by the above technical scheme include: precise pushing force control avoids pipeline damage and excessive deformation of sealing elements, ensures the quality of butt joint, reduces rework, and improves construction efficiency; the laser collimator monitors the axis deviation in real time, discovers deviation changes in time, avoids deviation accumulation, and ensures that the axis deviation is stably controlled within ≤0.5mm / m, providing a basis for uniform stress on the sealing element; high-frequency deviation recording makes the data complete and traceable, facilitating analysis of the causes of deviation, optimization of the pushing process, reduction of rework due to excessive deviation, and reduction of construction cost and risk of construction period delay; the three work together to realize precise and intelligent control of the pushing construction, solve the problem of unstable quality and dependence on experience in traditional pushing construction, ensure the axis precision and structural safety of the pipeline butt joint, and lay a good foundation for subsequent sealing steps.

[0038] The traditional technical scheme has the following technical problems: in the sealing element pressure detection of large-diameter water supply and drainage pipelines, the sensor spacing of the traditional pressure sensor array often exceeds 50mm, resulting in a monitoring blind area around the pipeline interface, especially when the pipeline diameter is large, local pressure abnormal areas are easily missed, and weak sealing points cannot be found; the measurement accuracy of the sensor is mostly ±0.5kPa, which cannot identify small pressure changes, and it is difficult to detect local slight underpressure or overpressure of the sealing element, which may leave leakage hazards; the pressure detection data is mostly transmitted by wired transmission, which is complex to wire, especially in harsh construction site environments, line faults are easily caused, resulting in data transmission interruption, inability to obtain pressure information in real time, missing the best calibration opportunity, and the need to reassemble the butt joint when problems are found later, which is high in cost and low in efficiency.

[0039] Therefore, in step 3, the sensor spacing of the pressure sensor array is 20-30mm, the measurement accuracy of the sensor is ±0.1kPa, and the pressure detection data is transmitted in real time to the control terminal through the wireless transmission module.

[0040] The scheme solves the problems of blind area, insufficient accuracy and transmission failure in traditional pressure monitoring through sensor spacing optimization, accuracy improvement and wireless transmission: the sensor spacing is 20-30 mm, which is designed according to the circumferential length of the large-diameter pipeline interface, can realize full coverage monitoring of the circumferential pressure, has no blind area, and can ensure that any area of pressure anomaly, such as insufficient sealing caused by local low pressure or damage to the sealing element caused by high pressure, can be captured; the measurement accuracy of ±0.1 kPa can accurately identify small pressure fluctuations, even a pressure change of 0.2 kPa can be detected, which can timely find local slight pressure anomalies of the sealing element and avoid missing potential hazards due to insufficient accuracy; the wireless transmission module uses industrial wireless communication technology, does not need wiring, adapts to complex construction site environment, avoids line failure problems of wired transmission, ensures real-time and stable transmission of pressure data to the control terminal, and enables workers to remotely monitor pressure changes and immediately calibrate the push device if an anomaly is found, without the need for on-site supervision, thereby improving efficiency.

[0041] It is worth mentioning that: the sensor spacing needs to be fine-tuned according to the diameter of the pipeline, the larger the diameter, the longer the circumferential length, and the spacing can be appropriately controlled at 30 mm, and the smaller the diameter, the spacing can be controlled at 20 mm, to ensure the balance between monitoring density and efficiency; the sensor needs to have good waterproof and moisture-proof performance to adapt to the humid environment of the construction site and avoid water damage; the wireless transmission module needs to be equipped with a signal enhancement device to ensure stable signal in complex construction environment, and the data transmission packet loss rate is ≤0.1%; the control terminal needs to have data storage and alarm functions, and when the pressure fluctuation exceeds 5%, it automatically sends an audible and visual alarm to remind workers to handle it in time; the sensor needs to be calibrated before installation to ensure consistent measurement accuracy and avoid monitoring errors caused by individual differences of the sensor.

[0042] The technical effects achieved by the above technical scheme include: dense sensor arrangement eliminates monitoring blind area, ensures full coverage of circumferential pressure, and avoids missing weak points of sealing, thereby improving the comprehensiveness of sealing pressure monitoring; high-precision sensors capture small pressure fluctuations and timely find potential sealing hazards, avoiding missing due to insufficient accuracy and improving monitoring reliability; wireless transmission ensures real-time and stable data transmission, adapts to complex construction environment, avoids monitoring interruption caused by line failure, and enables workers to obtain pressure information and quickly calibrate, thereby reducing rework and construction cost; the combination of the three makes the sealing pressure monitoring system have comprehensiveness, accuracy and real-time performance, fundamentally solves the defects of traditional monitoring methods, ensures uniform and stable circumferential pressure of the sealing element, provides key pressure protection for pipeline connection anti-seepage, and improves the reliability of the overall anti-seepage effect.

[0043] The traditional technical solution has the following technical problems: in the assembly construction of the sealing groove and the sealing element of the large-diameter water supply and drainage pipeline, the traditional process does not perform targeted treatment on the inner wall of the groove before the sealing element is embedded, dust, oil stains or oxide layers are easily left on the inner wall of the groove, which leads to insufficient adhesion between the sealing element and the inner wall of the groove, and under the action of long-term water pressure impact, pipeline vibration or temperature change, the sealing element is prone to relative displacement with the groove, which damages the sealing structure; although some processes use adhesive, the type and brushing parameters of the adhesive are not limited, and ordinary adhesive is often selected, which cannot adapt to the humid environment of the pipeline interface, and the brushing thickness is arbitrary (thick or thin), which easily leads to the accumulation of adhesive layer and causes the sealing element to be not assembled in place, and the adhesion effect is poor, and there is no standing and curing link, the adhesive is assembled with the sealing element before the stable adhesion strength is formed, which further reduces the adhesion reliability, and finally causes leakage risk.

[0044] Therefore, before the sealing element is embedded in the annular sealing groove in step 2, the inner wall of the sealing groove is also coated with a silane coupling agent, the brushing thickness of the silane coupling agent is 0.1-0.2mm, and the silane coupling agent is left to stand for 5-10min after brushing.

[0045] The scheme solves the core problem of insufficient adhesion in the traditional assembly through targeted groove inner wall pretreatment process: the silane coupling agent has excellent interface adhesion enhancement performance, can effectively remove the trace oil stains and oxide layers on the inner wall of the groove, and at the same time, builds a stable chemical adhesion interface between the inner wall of the groove and the sealing element, especially suitable for the humid service environment of the pipeline interface, avoiding the poor water resistance problem of ordinary adhesive; the brushing thickness of 0.1-0.2mm is limited, which has been verified through multiple tests, which can not only ensure that the coupling agent uniformly covers the inner wall of the groove and forms a complete adhesive layer, but also will not cause the adhesive layer to overflow and affect the assembly accuracy of the sealing element due to excessive thickness, or cause adhesion blind area due to insufficient thickness; the silane coupling agent is left to stand for 5-10min after brushing, which provides sufficient preliminary curing time for the silane coupling agent, so that it can fully react with the inner wall of the groove to form a stable adhesion basis, avoid adhesion failure caused by assembly before curing, and ensure that the sealing element can form a firm combination with the groove after being embedded.

[0046] It is worth mentioning that: the silane coupling agent needs to be selected from amino type or epoxy type, which has good adhesion adaptability to pipeline materials such as metal and concrete and rubber sealing elements; a dust-free brush or spraying equipment needs to be used for brushing to ensure that the coating is uniform and bubble-free, and to avoid the influence of brush hair residues on adhesion; the standing environment needs to be kept ventilated and dry, and the temperature needs to be controlled at 5-35℃, to avoid slow curing caused by low temperature or accelerated curing caused by high temperature affecting the adhesion effect; for grooves with high inner wall roughness, the inner wall can be lightly sanded with fine sandpaper before brushing the coupling agent to remove sharp protrusions and ensure that the coupling agent can fully infiltrate the inner wall; the coupling agent needs to be protected from dust pollution after brushing, and a dustproof film can be covered until the standing is completed.

[0047] The technical effects achieved by the above technical solution include: the stable bonding interface constructed by the silane coupling agent can effectively prevent the relative displacement of the sealing element and the groove under water pressure, vibration or temperature change, and ensure the long-term stability of the sealing structure; the precise brushing thickness and standing time make the bonding effect controllable, avoid bonding failure caused by improper parameters, and ensure the assembly accuracy of the sealing element; the pretreatment step cooperates with subsequent steps such as sealing element embedding and axis calibration, further improves the overall reliability of the sealing system, and reduces the leakage risk caused by the displacement of the sealing element; especially in the scene where the underground water level is high and the pipeline vibrates frequently, the anti-leakage ability of the interface can be significantly improved, the service life of the pipeline interface can be prolonged, and the problem of easy falling off and sealing failure of the sealing element in the traditional process can be solved.

[0048] The traditional technical solution has the following technical problems: in the backfill construction of the large-diameter water supply and drainage pipeline interface, the thickness of each layer of the traditional layered backfill is often more than 300 mm, which causes the compaction equipment to be unable to fully compact the backfill material, and the compaction degree is usually less than 90%, and voids are easily generated due to the settlement of the backfill soil in the later period. Under the action of underground water or ground load, the voids extrude the pipeline interface, causing the interface to deform and damage the seal; the backfill material is usually ordinary sand or soil without clear gradation requirements, and the particle distribution is uneven, which easily causes local arching or high density, and cannot form a uniform stress buffer layer; and no functional material is added, and when there is underground water around, the backfill material has poor anti-seepage performance, underground water easily seeps into the interface area, accelerates the aging of the sealing element or the corrosion of the pipeline, and the backfill of the soil is easily softened after being soaked in rainwater, further aggravating the settlement risk and affecting the anti-seepage effect of the interface.

[0049] Therefore, in step 4, the thickness of each layer of the layered backfill is 200-300 mm, the backfill material is graded sand, the sand particle size range is 5-20 mm, and 3%-5% of bentonite is mixed in the backfill material. This scheme solves the settlement, uneven stress and anti-seepage defects of the traditional backfill construction through backfill parameter optimization and material improvement: the backfill thickness of 200-300 mm of each layer adapts to the compaction capacity of commonly used compaction equipment (such as small vibratory road rollers and impact rammers), which can ensure that each layer of backfill material is fully compacted, the compaction degree is stable and reaches ≥95%, and incomplete compaction caused by excessive thickness is avoided; the graded sand is matched according to a specific ratio, the coarse particles form a skeleton structure to improve the overall strength of the backfill body, and the fine particles fill the gaps between the skeleton to make the backfill body dense and uniform, without local arching or overcompaction, which can provide uniform support and stress buffer for the pipeline interface; the mixing of 3%-5% of bentonite forms a dense anti-seepage layer in the backfill body by using the swelling property of bentonite when it comes into contact with water, which prevents underground water from seeping into the interface area, and the swelling property of bentonite can compensate for the slight settlement of the backfill body, further improving the stability of the backfill body.

[0050] It is worth mentioning that: graded sandstone needs to meet the grading requirements of GB / T14685-2022 "Construction with pebble, gravel", and through screening to ensure that the particle size of 5-20mm accounts for ≥90%, to avoid mixing large particles of more than 20mm or less than 5mm dust; bentonite needs to be selected as sodium-based bentonite, which has better swelling multiple and anti-seepage performance than calcium-based bentonite, and needs to be crushed to a particle size of ≤0.15mm before mixing to ensure uniform dispersion in the sandstone; backfilling needs to be symmetrically layered from both sides of the pipeline to avoid unilateral backfilling leading to pipeline deviation; compaction equipment needs to be selected according to the backfilling thickness, impact rammer can be used for 200-250mm thickness, small vibrating roller can be used for 250-300mm thickness, compaction times are controlled within 3-5 times to ensure that the compaction degree meets the standard; the water content of the backfilling body needs to be controlled during the backfilling process, and kept within the range of ±2% of the optimum water content, to avoid high water content leading to rolling and slurry or low water content leading to insufficient compaction degree.

[0051] The technical effects achieved by the above technical solutions include: the settlement of the uniformly compacted backfilling body is greatly reduced, which can provide stable support for the pipeline interface for a long time, avoiding interface deformation and sealing failure caused by settlement extrusion; the uniform structure of graded sandstone makes the stress around the interface balanced, reducing the damage of local stress concentration to the interface; the anti-seepage layer formed by bentonite effectively blocks the infiltration of groundwater, protecting the sealing element and the pipeline interface from water erosion and corrosion, and prolonging the service life of the interface; the synergistic effect of the high strength and anti-seepage of the backfilling body makes the pipeline interface still maintain stable anti-seepage performance under complex geology and external load, solving the problems of large settlement, poor anti-seepage and uneven stress in traditional backfilling construction, and providing reliable external protection for the pipeline interface.

[0052] The traditional technical solutions have the following technical problems: in the construction of the elastic buffer layer of the large-diameter water supply and drainage pipeline interface, the traditional buffer layer is often made of ordinary rubber material, which has poor aging resistance and oil resistance, and is easy to crack and lose buffering capacity under the action of corrosive substances in the soil or groundwater for a long time; the fixation of the buffer layer and the pipeline interface often depends on its own friction, without using adhesive or with insufficient bonding strength, and when the soil settles or the pipeline expands and contracts, the buffer layer is easy to separate from the pipeline, which cannot play a buffering protection role; the spacing of the fixing clamp is often more than 250mm, and the material of the clamp is often ordinary carbon steel, which is easy to rust and break, causing local loosening of the buffer layer, and under the action of external impact load, the buffer layer is easy to break, which cannot effectively absorb impact energy, and further causes stress damage to the interface and destroys the sealing structure.

[0053] Based on this, the elastic buffer layer in step 4 is made of nitrile rubber material, the inside of the buffer layer is coated with epoxy adhesive, the bonding strength of the adhesive is ≥2.5MPa, the buffer layer is fixed on the outside of the pipeline interface by stainless steel clamps, and the spacing of the clamps is 150-200mm.

[0054] The scheme solves the problems of traditional buffer layer, such as easy aging, falling off and damage, through material upgrading, bonding strengthening and fixing optimization: the nitrile rubber material has excellent oil resistance, aging resistance and wear resistance, can resist the corrosion of corrosive substances in the soil and underground water, and is not easy to crack for long-term use, ensuring the durability of the buffer layer; the epoxy adhesive has a bonding strength of ≥2.5MPa, which is much higher than that of traditional adhesive, and can tightly bond the buffer layer and the pipeline interface, even when the pipeline expands or contracts with temperature changes or the soil settles, the buffer layer and the pipeline interface can avoid separation, ensuring the continuous and effective buffering effect; the stainless steel clamp is corrosion-resistant and not easy to break, with a spacing of 150-200mm, which can evenly disperse the fixing force, ensure that the buffer layer is tightly attached to the pipeline interface in all directions, avoid local loosening, and under external impact load, the clamp can effectively fix the buffer layer, fully absorb the impact energy, and protect the interface from damage.

[0055] It is worth mentioning that: the hardness of the nitrile rubber buffer layer should be controlled within the range of Shore A 60-70, which can provide sufficient elastic buffering and avoid excessive deformation caused by insufficient hardness; the epoxy adhesive should be two-component normal temperature curing type, the curing time should be controlled within 24 hours, and the bonding strength should be tested after curing to ensure that it meets the standard; the width of the stainless steel clamp should be ≥20mm and the thickness should be ≥2mm to ensure sufficient bearing capacity, and a torque wrench should be used to tighten the clamp to control the tightening torque at , to avoid excessive torque causing buffer layer deformation or insufficient torque causing poor fixation; the outside of the pipeline interface should be rusted before laying the buffer layer to ensure that the adhesive can be well combined with the pipeline surface; for areas with large temperature differences, a layer of thermal insulation layer can be wrapped outside the buffer layer to reduce the impact of temperature changes on the interface.

[0056] The technical effects achieved by the above technical scheme include: the excellent weather resistance and corrosion resistance of the nitrile rubber buffer layer ensure that the buffer layer is long-term effective and prolongs the service life of the interface protection; the synergistic fixation of high-strength epoxy adhesive and stainless steel clamp makes the buffer layer tightly attached to the pipeline interface, avoiding falling off or loosening, and ensuring the continuous and stable buffering effect; the buffer layer can effectively absorb the stress caused by external impact load and soil settlement, reducing the stress damage to the interface and protecting the integrity of the sealing structure; under the road below the frequent passing of vehicles or in the area where the earthwork is frequently excavated, the buffer protection system can significantly improve the anti-interference ability of the pipeline interface, reduce the risk of leakage caused by external factors, and solve the problems of weak protection ability and short service life of traditional buffer layer, providing all-round elastic protection for the pipeline interface.

[0057] The traditional technical solution has the following technical problems: in the large-diameter water supply and drainage pipeline interface pressure maintaining detection construction, the pressure maintaining detection interval between the pressure and the leakage amount record is often more than 10 minutes, which cannot capture the pressure drop or the leakage amount mutation in a short time, and is easy to miss the intermittent leakage or early micro-leakage, resulting in that the unqualified interface is misjudged as qualified, and leakage occurs in the later operation; when the pressure drop is greater than or equal to 0.05 MPa or the leakage amount exceeds the limit, the traditional process does not have clear treatment measures, and the leakage problem is not eliminated, resulting in high cost of later rework.

[0058] Therefore, in step 5, the pressure value and the leakage amount are recorded every 5 minutes during the pressure maintaining detection process, and if the pressure drop is greater than or equal to 0.05 MPa or the leakage amount exceeds the limit, the pressure maintaining is stopped and steps 2-3 are re-executed. The scheme solves the problems of missing judgment and improper treatment of the traditional pressure maintaining detection by high-frequency recording and standardizing abnormal treatment: recording the pressure and the leakage amount every 5 minutes can track the detection data changes in real time, and find the pressure fluctuation and the leakage amount anomaly in a short time, especially for intermittent leakage, such as local temporary adhesion of the sealing element and then displacement or early micro-leakage, the leakage amount increases slowly, which can be accurately captured to avoid missing judgment; the treatment measures when the pressure drop is greater than or equal to 0.05 MPa or the leakage amount exceeds the limit are to stop the pressure maintaining and re-execute steps 2-3, i.e. to embed the sealing element, calibrate the axis and detect the pressure, instead of simple treatment, which can find the problem from the root, such as axis deviation exceeding the limit, uneven pressure of the sealing element, damage of the sealing element, etc., and through re-execution of the core sealing step, the leakage problem is completely eliminated to ensure that the interface meets the anti-leakage performance; the standard abnormal treatment process avoids the secondary leakage caused by the random treatment measures in the traditional process, and ensures the closed-loop control of detection and repair.

[0059] It is worth mentioning that: the recorded data should be in table form, clearly marked with recording time, pressure value, leakage amount and recorder, for easy tracing and problem analysis; when the pressure drop is greater than or equal to 0.05 MPa, it is necessary to check whether the pressure maintaining equipment leaks first, and then check the interface sealing problem after excluding the equipment factors; when the leakage amount exceeds the limit, soap water can be used to smear the outside of the interface to observe whether bubbles are generated to assist in locating the leakage point; when steps 2-3 are re-executed, the original sealing element needs to be removed first to check whether there is damage or impurities on the inner wall of the groove, and the silane coupling agent needs to be re-coated if necessary to ensure that the sealing foundation is intact; when the pressure maintaining detection is re-executed, the first recording interval needs to be extended to 2 minutes, and the pressure change needs to be closely observed before the 5-minute recording interval is restored; all abnormal treatment processes need to be recorded in writing and included in the construction file.

[0060] The technical effects achieved by the above technical solutions include: high-frequency data recording ensures the accuracy of pressure maintenance detection, effectively avoids missed intermittent leakage and early micro-leakage, and improves detection reliability; the standardized abnormality processing procedure can completely eliminate leakage risks, avoid post-rework, and reduce construction cost and risk of construction period delay; re-execution of the core sealing step ensures that the interface sealing structure meets the design requirements, fundamentally solving the leakage problem; the complete recording and tracing system facilitates construction quality control and post-operation and maintenance, and if leakage occurs later, the cause can be quickly located through historical records; the detection and processing mechanism strictly controls the anti-leakage quality of the pipe interface, ensures that each interface can meet the long-term operation requirements, solves the drawbacks of traditional pressure maintenance detection, which focuses on detection and neglects processing, and forms a closed-loop quality control from detection, abnormality, repair to re-detection.

[0061] The traditional technical solutions have the following technical problems: in the laser scanning construction of the large-diameter water supply and drainage pipeline connecting end face, the scanning accuracy of the traditional laser profiler is often lower than ±0.01mm, which cannot accurately capture the small concave or convex of the end face, resulting in that the subsequent grinding can only deal with the macro-unevenness and the micro-defects are left, affecting the fit of the sealing element and the end face; the scanning range often does not cover the entire end face, especially ignoring the edge transition area of the end face, resulting in incomplete edge grinding and forming a sealing blind area; the scanning data is only used for visual observation, and a three-dimensional model is not generated through a data analysis module, which cannot quantify the end face topography parameters such as roughness and flatness, and cannot accurately determine the grinding area and grinding amount, resulting in that the grinding relies on manual experience, and the grinding is excessive or insufficient, the excessive grinding will weaken the pipe wall thickness and affect the structural strength, and the insufficient grinding cannot meet the design roughness requirement, finally affecting the sealing effect.

[0062] Based on this, the scanning accuracy of the laser profiler in step 1 is ±0.01mm, the scanning range covers the entire pipeline connecting end face, and the scanning data generates an end face topography three-dimensional model through a data analysis module, and the model is used to determine the grinding area and grinding amount.

[0063] The scheme solves the problems of insufficient precision, incomplete range and insufficient data utilization of traditional laser scanning through high-precision scanning, full-range coverage and data modeling: the scanning precision of ±0.01 mm can accurately identify the 0.01 mm level of the end face micro-defects, provide accurate defect position and depth data for subsequent grinding, and ensure that the micro-defects are completely removed; the scanning range covers the entire end face, including the edge transition area, avoiding the edge sealing blind area, and ensuring that the entire end face area can meet the design flatness and roughness requirements; the three-dimensional model generated by the data analysis module can intuitively quantify the end face topography parameters such as roughness Ra value and flatness error, and automatically divide the grinding area such as defect concentration area and high roughness area according to the defect depth and roughness requirements to calculate the accurate grinding amount, avoiding excessive or insufficient grinding caused by manual experience, and ensuring that the end face quality meets the standards after grinding without affecting the pipe wall thickness.

[0064] It is worth mentioning that: the laser profiler needs to use a line laser type, and the scanning speed needs to be controlled at 50-100 mm / s, taking into account the scanning efficiency and accuracy; the profiler needs to be calibrated before scanning, using a standard gauge to calibrate the scanning precision to ensure accurate measurement; the three-dimensional model needs to use STL format to facilitate import into the control system of the grinding equipment to realize automatic planning of the grinding path; the data analysis module needs to have an automatic evaluation function of topography parameters, and if the end face roughness after scanning meets Ra≤0.8 μm, the grinding step can be directly skipped to save the construction period; for large-diameter pipes with a diameter exceeding 2000 mm, multiple laser profilers can be used for synchronous scanning, and then the data is spliced to generate a complete three-dimensional model to avoid insufficient scanning range of a single device; after the grinding area is determined, the grinding depth gradient needs to be marked in the three-dimensional model to ensure a gradual grinding process and avoid local stress concentration causing end face damage.

[0065] The technical effects achieved by the above technical scheme include: high-precision scanning ensures that the end face micro-defects are accurately identified to provide data support for complete grinding and avoid micro-defects causing sealing gaps; full-range scanning eliminates edge sealing blind areas to ensure that the entire end face area is sealed and fitted to reduce leakage channels; three-dimensional modeling and quantitative calculation of grinding parameters make the grinding process controllable and traceable, avoid excessive grinding weakening the pipe strength or insufficient grinding affecting the seal, while improving the grinding efficiency and reducing manual intervention; the scanning and modeling steps lay a high-quality end face foundation for subsequent sealing steps, enabling the sealing element to fully play its role and improving the overall anti-seepage effect; especially in large-diameter pipe construction, it can significantly improve the accuracy and consistency of end face processing, solve the problem of unstable quality of traditional manual grinding, and realize the intelligentization and standardization of pipe end face processing.

[0066] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the disclosed technical content into equivalent embodiments with equivalent changes, and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solution content of the present application, still falls within the protection scope of the present application.

Claims

1. A method of preventing seepage in a large diameter water supply and sewerage pipeline connection, characterized by, The method comprises the following steps: Step 1: scanning the pipe connection end face with a laser profiler, and controlling the micro-morphology of the connection end face through a grinding device according to the scanning results, so that the end face roughness Ra is less than or equal to 0.8 μm and a ring-shaped sealing groove is formed, and the groove width is 1 / 5-1 / 4 of the pipe wall thickness; Step 2: selecting a temperature-adaptive elastic sealing element, embedding the sealing element in the ring-shaped sealing groove, adjusting the axial deviation of the two pipes to be less than or equal to 0.5 mm / m through a hydraulic pushing device, and simultaneously applying a pre-compression amount of 3%-5% to the sealing element; Step 3: detecting the circumferential contact pressure of the sealing element by using a pressure sensor array, ensuring that the pressure fluctuation is less than or equal to 5%, and if the pressure is abnormal, the pushing device is calibrated again; Step 4: wrapping an elastic buffer layer outside the pipe interface, the buffer layer thickness is 10-15 mm, and then performing layered backfilling, and the compaction degree of each layer of backfilling material is greater than or equal to 95%; Step 5: performing pressure maintaining detection on the interface by using a water pressure leakage detection device, the pressure maintaining pressure is 1.2 times the design working pressure of the pipe, the pressure maintaining time is greater than or equal to 30 minutes, and the leakage amount is monitored by a flow sensor during the detection process, and if the leakage amount is less than or equal to 0.01 L / (m·h), it is determined to be qualified.

2. A method of preventing infiltration in a large diameter water supply and sewerage pipeline joint according to claim 1, characterized in that, In step 1, the grinding head rotation speed of the grinding device is 800-1200 r / min, and an aqueous grinding fluid is used during the grinding process, and the abrasive particle size in the grinding fluid is 10-20 μm.

3. The method of claim 1, wherein the method further comprises: The temperature-adaptable elastic seal in step 2 is made of ethylene-propylene-diene rubber, and a metal reinforcing framework is embedded in the seal. The difference between the linear expansion coefficients of the metal reinforcing framework and the pipeline material is ≤1×10 -6 / ℃.

4. The method of claim 1, wherein, In step 2, the pushing force of the hydraulic pushing device is controlled to be 50-80 kN, and the axial deviation is monitored in real time by a laser collimator during the pushing process, and the deviation value is recorded once every 5 mm of pushing.

5. The method of claim 1, wherein the method further comprises: In step 3, the sensor spacing of the pressure sensor array is 20-30 mm, the measurement accuracy of the sensor is ±0.1 kPa, and the pressure detection data is transmitted in real time to the control terminal through a wireless transmission module.

6. The method of claim 1, wherein, In step 2, before embedding the sealing element in the ring-shaped sealing groove, it also includes the step of brushing silane coupling agent on the inner wall of the sealing groove, and the brushing thickness of the silane coupling agent is 0.1-0.2 mm, and the brushing is placed for 5-10 minutes after brushing.

7. The method of claim 1, wherein the method further comprises: In step 4, the thickness of each layer of layered backfilling is 200-300 mm, the backfilling material is graded sandstone, the sandstone particle size range is 5-20 mm, and 3%-5% of bentonite is added to the backfilling material.

8. The method of claim 1, wherein, In step 4, the elastic buffer layer is made of nitrile rubber material, the inside of the buffer layer is brushed with epoxy adhesive, the adhesive bonding strength is greater than or equal to 2.5 MPa, the buffer layer is fixed outside the pipe interface by a stainless steel clamp, and the clamp spacing is 150-200 mm.

9. The method of claim 1, wherein, In step 5, during the pressure maintaining detection process, the pressure value and the leakage amount are recorded once every 5 minutes, and if the pressure drops by more than 0.05 MPa or the leakage amount exceeds the limit, the pressure maintaining is stopped and steps 2-3 are re-executed.

10. The method of claim 1, wherein the method further comprises: In step 1, the scanning accuracy of the laser profiler is ±0.01 mm, the scanning range covers the entire pipe connection end face, the scanning data generates an end face morphology three-dimensional model through a data analysis module, and the model is used to determine the grinding area and the grinding amount.

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