A trenchless pipeline repair method

Abstract

This application relates to a trenchless pipeline repair method, belonging to the field of pipeline repair technology. The trenchless pipeline repair method includes the following steps: S1, pipeline damage detection to determine the repair location; S2, calculation and evaluation of the pipeline damage degree to determine the required trenchless pipeline repair method; S3, calculation of the repair pipeline specifications according to the pipeline repair requirements, and pipeline repair according to the corresponding repair method; S4, post-repair testing to verify whether the repair effect is qualified. The solution provided in this application determines the pipeline repair method through pipeline operation risk level calculation and pipeline usage attributes, and calculates the repair pipeline wall based on the drainage flow, water supply flow, and pressure requirements that the pipeline should meet. This effectively shortens the pipeline repair design cycle, improves the reliability of pipeline repair, shortens the pipeline repair construction cycle, reduces the scope of construction impact and safety risks, and avoids affecting the normal operation of the airport.

Description

Technical Field

[0001] This application relates to a trenchless pipeline repair method, belonging to the field of pipeline repair technology. Background Technology

[0002] Over the years of airport operation and maintenance, the repair and renovation of old and outdated pipeline facilities has always been a challenging issue, especially in the apron area. Traditional excavation repair techniques involve long construction cycles, large impact areas, and significant safety risks, which can severely disrupt normal airport operations. Trenchless pipeline repair technology effectively solves the problems of significant environmental damage, long construction cycles, and high costs associated with traditional excavation repair of pipeline networks. It avoids large-scale excavation within the flight area, minimizing the impact on airport operations and reducing safety risks during construction. Therefore, this application aims to address the problem of accurately locating and repairing leaks and damage points in the water supply and drainage pipeline network without affecting normal airport operations and maintenance. Summary of the Invention

[0003] To address or partially address the problems existing in related technologies, this application provides a trenchless pipeline repair method. This method can determine the pipeline repair method by calculating the pipeline's operational risk level and usage attributes. It calculates the pipeline wall repair requirements based on the required drainage flow, water supply flow, and pressure, effectively shortening the pipeline repair design cycle and improving the reliability of the pipeline repair. By using the trenchless pipeline repair method and conducting tests such as water tightness tests, water flow tests, and pressure tests, the pipeline repair construction cycle is shortened, the scope of construction impact and safety risks are reduced, and the disruption to the normal operation of the airport is avoided.

[0004] The first aspect of this application provides a trenchless pipeline repair method, comprising the following steps:

[0005] Step S1: Pipe damage detection to determine repair location;

[0006] Step S2: Calculate and evaluate the degree of pipeline damage. Based on the pipeline operation risk level assessment, it is divided into three levels: low, medium, and high, to determine the trenchless pipeline repair method to be used.

[0007] Step S3: Determine the specifications of the pipeline to be repaired based on the required water flow rate and pressure, and repair the pipeline according to the corresponding repair method.

[0008] Step S4: After repair, check and verify whether the repair effect is qualified.

[0009] Optionally, in step S1, the pipeline damage detection process involves using a segmented water tightness detection method to detect leaks in each pipeline to determine if a leak is occurring. Then, a CCTV pipeline endoscopic television detection system is used to accurately detect the leak point, detecting and photographing conditions such as rust, scale corrosion, perforation, and cracks within the pipeline. For pressurized pipelines, a noise detection point system can be used to accurately locate the leak point. The CCTV pipeline endoscopic television detection system is then used for imaging, and finally, a complete detection report is issued, providing an important basis for developing a repair plan.

[0010] Optionally, in step S2, the pipeline damage degree calculation process involves classifying pipeline defects into structural defects and functional defects, further categorizing structural and functional defects, and determining the corresponding defect level, defect influence coefficient, and defect score. Then, the pipeline defect score is determined according to the pipeline defect condition assessment score calculation formula, which is as follows:

[0011]

[0012] In the formula, L represents the total length of the pipeline being evaluated. i P represents the longitudinal distance length of the i-th defect. i E represents the defect score of the i-th defect. i The defect length coefficient represents the i-th defect, and n represents the total number of defects;

[0013] Based on the assessment score of pipeline defect status, three defect levels are defined: S≥7 is Level III, 4≤S<7 is Level II, and S<4 is Level I.

[0014] Determine the failure consequence risk assessment scoring coefficient and failure consequence weight, calculate the pipeline failure consequence risk assessment score, and classify the failure consequence risk level into three levels: Level I, Level II, and Level III, based on the failure consequence assessment score. The formula for calculating the pipeline failure consequence risk assessment score is as follows:

[0015]

[0016] In the formula, q i e represents the risk assessment score coefficient for the i-th failure consequence. i represents the risk assessment weight of the i-th failure consequence, and n represents the total number of failure consequence assessments;

[0017] The three defect levels are determined based on the failure consequence assessment score: R≥7 is Level III, 4≤R<7 is Level II, and R<4 is Level I.

[0018] The pipeline operation risk level is assessed based on a combination of the pipeline defect level and the risk level of failure consequences, and is divided into three levels: low, medium, and high.

[0019] Optionally, the pipeline operation risk level assessment rules are as follows: low-level operation risk is a combination of Level I pipeline defect and Level I failure risk level, Level I pipeline defect and Level II failure risk level, and Level II pipeline defect and Level I failure risk level; medium-level operation risk is a combination of Level II pipeline defect and Level II failure risk level, and Level I pipeline defect and Level III failure risk level; high-level operation risk is a combination of Level II pipeline defect and Level III failure risk level, Level III pipeline defect and Level I failure risk level, Level III pipeline defect and Level II failure risk level, and Level III pipeline defect and Level III failure risk level.

[0020] Optionally, in step 3, the process of determining the repair method is as follows: the pipeline repair method is determined based on the pipeline operation risk assessment level and the pipeline type. For drainage pipelines with high operation risk levels, the expansion and short pipe insertion method is used for repair. For water supply pipelines with high operation risk levels, the pipeline is directly refurbished without repair.

[0021] Drainage pipes and water supply pipes with medium operational risk levels are repaired using the flexible hose lining method;

[0022] For drainage pipes with low operational risk, spraying is used to repair pipe defects; for tap water pipes with low operational risk, ultraviolet light curing is used for repair.

[0023] Optionally, in step S3, when repairing the pipeline using the expansion and short pipe insertion method, the specifications of the short pipe are first determined, and the formula for calculating the pipe wall thickness is as follows:

[0024]

[0025] In the formula, t represents the inner pipe wall thickness, 0.721 represents a coefficient, C represents the ellipticity reduction factor, N represents the safety factor, D0 represents the original pipe inner diameter, and q t The total external pressure of the pipeline is represented by EL, the long-term elastic modulus of the short pipe is represented by RW, the buoyancy coefficient is represented by B', and the elastic support coefficient is represented by E'. S Indicates the overall deformation modulus of the soil along the pipe;

[0026] After determining the specifications of the short pipe, the short pipe insertion process is carried out to complete the bursting of the original pipe and the installation of the short pipe.

[0027] Optionally, in step S3, when using the flexible hose lining method for semi-structural pipe repair, the lining pipe should be able to withstand the external groundwater pressure and vacuum pressure, as well as the internal water pressure at the damaged part of the original pipe. The formula for calculating the lining pipe wall thickness is as follows:

[0028]

[0029] In the formula, t represents the wall thickness of the inner lining pipe, Do represents the outer diameter of the inner lining pipe, K represents the circumferential support ratio, and E... L C represents the long-term elastic modulus of the inner liner, and P represents the ellipticity reduction factor. W P represents the groundwater pressure at the top of the inner lining pipe. v The value represents the vacuum pressure, N represents the circumferential stability resistance coefficient of the pipe cross section, and μ represents Poisson's ratio, which is determined according to the lining material.

[0030] After determining the specifications of the inner lining hose, a working pit is excavated, the interior of the original pipeline is pre-treated, the new inner lining hose is pulled using the existing inspection well and working pit, and finally the pipeline is connected.

[0031] Optionally, in step S3, when using the ultraviolet light curing repair method, the calculation method for the total thickness of the pipe impregnation resin and the hose is the same as that for the hose lining method. After determining the thickness of the impregnation resin and the hose, the upstream pipe is first sealed, then the pipe is cleaned, a gasket is pre-installed inside the cleaned pipe, the resin-impregnated hose is pulled into the original pipe along the gasket, the resin tube is inflated to make the resin tube fully adhere to the original pipe, and at the same time, the hose material is cured by irradiating it with a special wavelength of ultraviolet light, and finally the pressure is reduced to complete the repair.

[0032] The first optional step, step S3, involves repairing drainage pipes with a low operational risk level using a spray coating method.

[0033] Place the spraying equipment on one side of the pipe to be repaired, ensuring that the longitudinal axis of the spraying equipment and the longitudinal axis of the pipe are aligned. Before spraying, pull the umbilical tube into place and install the nozzle at the front end of the umbilical tube. Select the nozzle according to the inner diameter of the pipe to be repaired. Use a pipe spraying robot to spray the defective area of ​​the pipe. Spray two to three times, with each spray thickness ranging from 1.2mm to 2.75mm. The time interval between each spraying should be 90-120 minutes.

[0034] Optionally, the S4 repair effect testing and verification process is as follows: After the pressureless pipeline repair work is completed, a CCTV inspection robot is placed inside the new pipeline to inspect the interior. Then, a pressureless pipeline water tightness test is conducted. The test pipe section is filled with water and soaked for no less than 24 hours. Timing begins when the test water head reaches the specified water head. The amount of water leakage in the pipeline is observed. Water is continuously added to the test pipe section to maintain a constant test water head until the observation ends. When the leakage meets the specifications, the pipeline water tightness test is considered qualified. For short pipes with abnormal conditions, expansion work is carried out. The number of expansions for a single short pipe should be less than 2. For deformed or out-of-round short pipes, the pipe head should be cut off. After repairing the pipeline, the pipe should be re-inserted for repair. Short pipes that leak during the water test should be cut off and replaced.

[0035] After the repair of the pressurized pipeline, use a CCTV robot to inspect and accept the internal appearance quality of the pipeline again. Conduct a sectional water pressure test for the pipeline, and also conduct a water pressure test for each branch pipe to ensure that the pipeline has no leakage.

[0036] Optionally in the first aspect, the process of the non-pressurized pipeline water tightness test is as follows: The pipeline water tightness test shall be carried out in accordance with the standard specifications. When the water leakage volume meets the specification requirements, the pipeline water tightness test is qualified. The calculation formula for the measured water seepage volume is

[0037] q = W / T·L (5)

[0038] In the formula, q is the measured water seepage volume, W is the water replenishment volume, T is the actual water seepage observation time, and L is the length of the test pipe section.

[0039] Optionally in the first aspect, after the pipeline is repaired by the ultraviolet light curing repair method, when the CCTV inspection robot inspects the inside of the new pipeline, it shall be determined that the inner lining pipe wall has no delamination and no peeling, the average wall thickness at any point of the inner lining pipe is not less than the design value, the initial ring stiffness of the inner lining pipe is greater than the specified value, the perpendicularity deviation of the end of the inner lining pipe does not exceed the allowable range, the inner lining pipe and the repaired pipeline shall be closely adhered, there is no water leakage at the end gap, the inner wall of the inner lining pipe shall have no more than 5 continuous folds, and the relative height of the folds is not greater than 2% of the inner diameter of the pipeline, and there are no more than 2 continuous local depressions, bulges, and bubbles, and the height does not exceed 5% of the pipe diameter.

[0040] Optionally in the first aspect, conduct hydraulic calculation, pipeline flow calculation, flow velocity calculation, and calculation of the ratio of flow capacity for the pipeline after trenchless repair to ensure that the flow and water pressure of the repaired pipe section can meet the usage requirements.

[0041] The technical solution provided by this application may include the following beneficial effects: This application determines the pipeline repair method through the calculation of the pipeline operation risk level and the pipeline usage attributes, calculates the pipeline wall repair according to the drainage flow rate, water supply flow rate, and pressure requirements that the pipeline should meet, effectively shortening the pipeline repair design cycle, improving the reliability of pipeline repair, using the trenchless pipeline repair method for pipeline repair, and配合闭水试验、通水试验、加压试验进行检测,缩短了管道修复施工周期,减小了施工影响范围和安全风险,避免了影响机场的正常运行。

[0042] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] By describing the exemplary embodiments of the present application in more detail in combination with the accompanying drawings, the above and other objects, features, and advantages of the present application will become more obvious. Among them, in the exemplary embodiments of the present application, the same reference numerals generally represent the same components.

[0044] Figure 1 This is a schematic diagram of the pipeline repair process shown in the embodiments of this application;

[0045] Figure 2 This is a schematic diagram of the pipeline repair process using the expansion + short pipe insertion method shown in the embodiments of this application;

[0046] Figure 3 This is a schematic diagram of the hose lining method for pipe repair shown in the embodiments of this application;

[0047] Figure 4 This is a schematic diagram of the ultraviolet light curing repair process shown in the embodiments of this application. Detailed Implementation

[0048] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0049] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0050] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0051] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0052] The problem this application aims to solve is how to accurately locate and repair leaks and damage points in the water supply and drainage network without affecting the normal operation and maintenance of the airport.

[0053] To address the aforementioned issues, this application provides a trenchless pipeline repair method. This method determines the repair approach based on pipeline operational risk level calculations and pipeline usage attributes. It calculates the required drainage flow, water supply flow, and pressure for the pipeline wall, effectively shortening the pipeline repair design cycle and improving the reliability of the repair. By employing a trenchless pipeline repair method and conducting tests such as water tightness tests, water flow tests, and pressure tests, the construction period is shortened, the scope of construction impact and safety risks are reduced, and disruption to the normal operation of the airport is avoided.

[0054] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0055] like Figure 1 The diagram shown is a schematic representation of a pipeline repair process according to an embodiment of this application. The trenchless pipeline repair method of this application includes the following steps:

[0056] Step S1: Pipeline damage detection and repair location determination. A segmented water tightness detection method is used to detect leaks in each pipeline to determine if a leak exists. Then, a CCTV pipeline endoscopic television inspection system is used for accurate location. This system utilizes a pipeline CCTV inspection robot equipped with digital high-definition camera units at the front and rear, a portable handheld tablet control terminal, a powerful lighting source, and a high-precision meter-counting cable reel. The system automatically adjusts the cable reeling and unloading speed according to the robot's movement speed, and automatically arranges the cable during the reeling process. It can enter the pipeline to record video, capture defects, record defect location information, and generate a pipeline inspection report. The tablet control terminal analyzes the video recordings and defect captures to determine the condition of rust, scale corrosion, perforation, cracks, etc., within the pipeline, generating a complete inspection report that provides crucial information for developing a repair plan. For pressurized pipelines, a noise detection point deployment system can be used to accurately locate the leak point, which is then captured by the CCTV pipeline endoscopic television inspection system.

[0057] Step S2 involves calculating and evaluating the degree of pipeline damage, and determining the repair method based on the damage assessment level. Specifically, pipeline defects are categorized into structural and functional defects. These defects are then classified separately, and their respective level, defect influence coefficient, and defect score are assigned. Both structural and functional defects are classified into Level 1 (minor), Level 2 (moderate), and Level 3 (severe). Then, the various structural and functional defects are graded and assigned scores. The structural defect grading and score assignment are shown in Table 1 below.

[0058] Table 1. Names, classifications, and scores of structural defects.

[0059]

[0060]

[0061] The functional defect levels and their corresponding scores are shown in Table 2 below.

[0062] Table 2. Names, levels, and scores of functional defects.

[0063]

[0064]

[0065] Then, the pipeline defect score is determined according to the pipeline defect status assessment score calculation formula, which is as follows:

[0066]

[0067] In the formula, L represents the total length of the pipeline being evaluated. i P represents the longitudinal distance length of the i-th defect. i E represents the defect score of the i-th defect. i represents the defect length coefficient of the i-th defect, and n represents the total number of defects.

[0068] Based on the assessment score of pipeline defect status, three defect levels are defined: Level III is defined as an assessment score of S≥7, indicating that the pipeline has major defects, is severely damaged or is about to be damaged, and immediate repair is recommended; Level II is defined as an assessment score of 4≤S<7, indicating that the pipeline has certain defects and has a tendency to deteriorate, and semi-structural repair is recommended within a certain period; Level I is defined as an assessment score of S<4, indicating that the pipeline has no or minor defects, and lining pipeline repair is recommended within a certain period.

[0069] Next, the failure consequence risk assessment scoring coefficients and failure consequence weight allocation are determined. The failure consequence risk assessment scoring coefficients are allocated according to the number of users affected, the laying location, and the road grade, respectively. The pipeline failure consequence weight assessment indicators are allocated according to the number of users affected, the laying location, and the road grade, respectively. Then, the pipeline failure consequence risk assessment score is calculated. The formula for calculating the pipeline failure consequence risk assessment score is:

[0070]

[0071] In the formula, q i e represents the risk assessment score coefficient for the i-th failure consequence. i represents the risk assessment weight of the i-th failure consequence, and n represents the total number of failure consequence assessments;

[0072] Based on the failure consequence assessment score, three levels of failure consequence risk are defined: R≥7 is Level I, 4≤R<7 is Level II, and R<4 is Level III.

[0073] Finally, the pipeline operation risk level is assessed based on the combination of pipeline defect level and failure consequence risk level, and is divided into three levels: low, medium, and high, as shown in Table 3 below.

[0074] Table 3 Pipeline Operation Risk Level Assessment Table

[0075]

[0076] Step S3: Determine the pipeline repair method based on the pipeline operation risk assessment level. The pipeline repair method is determined based on the pipeline operation risk assessment level and pipeline type. Drainage pipelines with high operation risk level are repaired using the expansion and short pipe insertion method. Water supply pipelines with high operation risk level are directly refurbished without repair.

[0077] Drainage pipes and water supply pipes with medium operational risk levels are repaired using the flexible hose lining method;

[0078] Drainage pipes with low operational risk levels are repaired using a spraying method; water supply pipes with low operational risk levels are repaired using a UV curing method.

[0079] When repairing drainage pipes with high operational risk levels using the expansion joint and short pipe insertion method, the specifications of the short pipe must first be determined, and the formula for calculating the pipe wall thickness is as follows:

[0080]

[0081]

[0082]

[0083]

[0084] In the formula, t represents the inner pipe wall thickness, 0.721 represents a coefficient, C represents the ellipticity reduction factor, N represents the safety factor, D0 represents the original pipe inner diameter, and q t The total external pressure of the pipeline is represented by EL, the long-term elastic modulus of the short pipe is represented by B', and the elastic support coefficient is represented by E'. S RW represents the overall deformation modulus of the soil along the pipe, with a minimum value of 0.67, B' represents the elastic support coefficient, and E' represents the buoyancy coefficient. S H represents the comprehensive deformation modulus of the soil along the pipe. W γ represents the depth of the groundwater level above the top of the pipe, H represents the unit weight of the soil, and H represents the pipe laying depth. S W represents the thickness of the soil cover over the pipe. S Indicates live load;

[0085] The minimum wall thickness of the inner liner should meet the following formula:

[0086]

[0087] In the formula, E represents the initial elastic modulus of the inner liner tube;

[0088] After determining the specifications of the short pipe, the short pipe insertion process is carried out. A CCTV robot is used to guide the guide cable, and the expansion head is connected to the guide cable. The oil pipe is passed through the short pipe that meets the total repair length. The expansion head and control equipment are connected through the hydraulic oil pipe. The expansion head is put in through the starting well, and a winch is placed in the ending well on the other side. After the expansion equipment is introduced into the pipeline, the ground control device pulls the expansion head forward while controlling the expansion head to break the original pipeline. The short pipe at the tail of the expansion head moves forward together to ensure that the broken pipeline will not be crushed by the overburden. The end of the short pipe is equipped with a top plate. The sockets of the two short pipes are pressed together by jacks. The short pipe insertion work is completed by connecting them in sequence.

[0089] When using the flexible hose lining method for semi-structural pipeline repair, the lining pipe should be able to withstand the external groundwater pressure and vacuum pressure, as well as the internal water pressure at the damaged part of the original pipeline. The formula for calculating the lining pipe wall thickness is as follows:

[0090]

[0091] Pw = 0.0098Hw (9)

[0092]

[0093]

[0094] In the formula, t represents the wall thickness of the inner lining pipe, Do represents the outer diameter of the inner lining pipe, K represents the circumferential support ratio, which should preferably be 7.0, and E LThe long-term elastic modulus of the inner liner should be taken as 50% of the short-term modulus. C represents the ellipticity reduction factor, and P represents the long-term elastic modulus of the inner liner. W P represents the groundwater pressure at the top of the inner lining pipe. v The value of H represents the vacuum pressure, which should preferably be 0.05 MPa; N represents the circumferential stability resistance coefficient of the pipe cross-section, which should be taken as 2.0; μ represents Poisson's ratio, which should be determined according to the lining material; W The depth of the groundwater level above the top of the pipe is indicated by q, and the ellipticity of the original pipe is indicated by D. E D represents the average inner diameter of the existing pipe. min This indicates the minimum inner diameter of the existing pipe.

[0095] When the inner lining pipe wall thickness t calculated according to formula (4) meets the requirements of formula (12), the inner lining pipe wall thickness design value should be checked according to formula (13). When the inner lining pipe wall thickness t calculated according to formula (4) does not meet the requirements of formula (12), the inner lining pipe wall thickness design value should be checked according to formula (14).

[0096]

[0097]

[0098]

[0099] In the formula, d represents the maximum diameter of the gap or hole in the original pipe, and σ L The long-term bending strength of the lining pipe should be taken as 50% of the short-term bending strength, P. d The design pressure of the pipeline should be calculated as 1.5 times the working pressure of the pipeline. (D) n Indicates the calculated diameter of the lining pipe, γ Q The partial factor representing the design internal water pressure, σ TL f represents the long-term tensile strength of the lining material. t This represents the resistance reduction factor.

[0100] After determining the specifications of the inner hose and confirming the specifications of the inner pipe, the water supply is stopped and the components in the inspection well are removed. The inner lining reel is installed in the starting well. A working pit is excavated at the main pipe connection in the terminal well, and a winch is installed. Connecting flanges or wall-mounted connectors are installed in the starting and terminal wells to clean the original pipe. Then, the pipe pulling operation is carried out, the main pipe is cut, and a special branch pipe joint is installed. The above steps are repeated to install the inner hose of the branch pipe. After the installation is completed, a pressure test is performed.

[0101] For drainage pipes with low operational risk levels, spraying is used for repair. The spraying equipment is placed on one side of the pipe to be repaired, and the longitudinal axis of the spraying equipment and the longitudinal axis of the pipe to be repaired should be in a straight line. Before spraying, the umbilical pipe is pulled into place and a nozzle is installed at the front end of the umbilical pipe. The nozzle is selected according to the inner diameter of the pipe to be repaired. A pipe spraying robot is used to spray the defective location of the pipe. Two to three sprays are applied, with each spray thickness ranging from 1.2mm to 2.75mm. The time interval between each spray is 90-120 minutes.

[0102] For the UV curing repair method, the calculation method for the total thickness of the pipe impregnation resin and hose is the same as that for the hose lining method. After determining the thickness of the impregnation resin and hose, the upstream pipe is first sealed with a water plug, then a high-pressure flushing truck is used to clean the inside of the pipe, followed by a CCTV robot to investigate the condition of the inside of the pipe. Then, a layer of liner is pre-laid inside the cleaned pipe. The liner should be placed at the bottom of the original pipe and should cover more than 1 / 3 of the pipe circumference. Pull-limiting pulleys are installed at both ends of the original pipe. The resin-impregnated hose is then pulled smoothly and slowly along the liner at the bottom of the pipe. Insert the resin into the existing pipeline; install the inflation device at the inlet end of the hose, and install a pressure regulating valve at the end of the hose to inflate the resin tube, so that the resin tube is fully and tightly attached to the original pipeline; place the ultraviolet lamp into the repair pipe that has been filled with compressed air, and set the traction speed of the traction machine and the curing speed according to the characteristics of the material itself. Use a special wavelength of ultraviolet light to irradiate the repair material for curing. During the ultraviolet curing process, a certain air pressure should be maintained in the inner lining tube to ensure that the inner lining tube is in close contact with the original tube. After the resin curing is completed, slowly reduce the pressure in the tube to natural atmospheric pressure.

[0103] Step S4: Post-repair testing and verification to determine if the repair effect is satisfactory. The repair effect testing and verification includes the following:

[0104] After repairing the pipeline using the expansion and short pipe insertion method, a CCTV inspection robot is placed inside to inspect the interior of the new pipeline to confirm whether there is any deformation, cracking, or misalignment of the socket. Then, a pressureless pipeline water tightness test is conducted. The pressureless pipeline water tightness test should meet the following requirements: When the upstream design head of the test section does not exceed the inner wall of the pipe top, the test head should be calculated as the upstream inner wall of the test section plus 2m; when the upstream design head of the test section exceeds the inner wall of the pipe top, the test head should be calculated as the upstream design head of the test section plus 2m; when the calculated test head is less than 10m but exceeds the height of the upstream manhole, the test head should be based on the height of the upstream manhole. The pipeline water tightness test should be conducted according to specifications. During the pipeline water tightness test, a visual inspection should be performed, and there should be no leakage during the test.

[0105] After the test pipe section is filled with water, the soaking time shall not be less than 24 hours. Start timing when the test water head reaches the specified water head, observe the water leakage of the pipeline, continuously replenish water into the test pipe section to keep the test water head constant until the observation ends. When the water leakage meets the requirements of the standard, the pipeline closed water test is qualified; the calculation formula for the actual water leakage of non-pressure pipeline closed water test is

[0106] q = W / T·L (15)

[0107] In the formula, q is the actual water leakage, W is the water replenishment, T is the actual water leakage observation time, and L is the length of the test pipe section.

[0108] For short pipes with abnormal conditions, supplementary expansion operations shall be carried out. The number of supplementary expansion times for one short pipe shall be less than 2 times. For deformed and out-of-round short pipes, the pipe heads shall be cut off. After repairing the pipeline, re-pipe threading and repair shall be carried out. For short pipes with water leakage during the water test, pipe cutting and pipe replacement shall be carried out.

[0109] After the pipeline is repaired by the hose lining method, use the CCTV robot to inspect and accept the internal appearance quality of the pipeline again. Conduct a sectional closed water pressure test on the main pipeline of the lined hose, and also conduct a closed water pressure test on each branch pipe to ensure that there is no water leakage in the lined pipeline. The closed water pressure test is carried out under the conditions of a pressure of 50 kPa and a stable pressure for 15 h. If the pressure drop is less than 0.02 MPa, it is qualified.

[0110] After the pipeline is repaired by the ultraviolet light curing repair method, use the CCTV robot to inspect and accept the internal appearance quality of the pipeline again. It is determined that the inner lining pipe wall shall have no delamination and no peeling, the average wall thickness at any point of the inner lining pipe shall not be less than 90% of the design value, the initial ring stiffness of the inner lining pipe shall be greater than 8 KN / m2, the verticality deviation of the end of the inner lining pipe shall not be greater than 4 mm, the inner lining pipe shall be closely attached to the repaired pipeline, there shall be no water leakage at the end gap, the inner wall of the inner lining pipe shall have no more than 5 folds per continuous 50 m, and the relative height of the folds shall not be greater than 2% of the pipeline inner diameter. There shall be no more than 2 local depressions, bulges, and bubbles per continuous 50 m, and the relative height of the depressions, bulges, and bubbles shall not exceed 5% of the pipe diameter; then conduct a water passing test.

[0111] After the pipeline repair is qualified, hydraulic calculation, pipeline flow calculation, flow velocity calculation, and calculation of the ratio of flow capacity shall be carried out on the repaired pipeline to ensure that the flow and pressure of the repaired pipe section can meet the use requirements. The ratio of the head loss along the way of the non-excavation repaired pipe section to the head loss along the way of the pipe section before repair can be calculated according to the following formula

[0112]

[0113] In the formula, h y represents the head loss along the way of the pipe section before repair; h' y represents the head loss along the way of the pipe section after repair; C hIndicates the Hayson-Williams coefficient for the pre-repair pipe section; C' h This indicates the Hayson-Williams coefficient for the repaired pipe section; d i Indicates the inner diameter of the pipe section before repair; d' i Indicates the inner diameter of the pipe section after repair;

[0114] The Hayson-Williams coefficients for pipes of different materials can be taken from Table 4 below.

[0115] Table 4. Hayzen-Williams coefficients for pipes of different materials

[0116]

[0117]

[0118] The ratio of the friction head loss of the repaired water pipe section to the friction head loss of the pipe section before repair should not exceed 1.1.

[0119] Hydraulic calculations should be performed on the repaired pipeline to ensure that the repaired section meets the usage requirements. The flow rate of the repaired pipeline can be calculated using the following formula:

[0120] Q = Av (17)

[0121] In the formula, Q represents the design flow rate, V represents the flow velocity, and A represents the effective cross-sectional area of ​​the water flow.

[0122] The flow velocity in the pipeline after trenchless repair can be calculated using the following formula:

[0123]

[0124] In the formula, v represents the flow velocity, R represents the hydraulic radius, n represents the roughness coefficient, and I represents the hydraulic gradient.

[0125] The ratio of the pipe's flow capacity after repair to that before repair should be calculated using the following formula:

[0126]

[0127] In the formula, B represents the ratio of flow capacity before and after pipeline repair, and n e n represents the roughness coefficient of the existing pipeline. l D represents the roughness coefficient of the inner lining pipe. E D represents the original inner diameter of the pipe. I This indicates the inner diameter of the lining tube.

Claims

1. A trenchless pipe rehabilitation method, characterized in that, The trenchless pipeline repair method includes the following steps: Step S1, Pipeline damage detection and repair location determination; The pipeline damage detection includes using a segmented water tightness detection method to detect abnormal water leakage in each pipeline to determine whether the pipeline is leaking, and then using a CCTV pipeline endoscopic television detection system to accurately detect the leak point, detecting and photographing the condition of rust, scale corrosion, perforation, and cracks inside the pipeline. For pressurized pipelines, a noise detection point deployment system is used to accurately locate the leak point, and then the CCTV pipeline endoscopic television detection system is used for imaging. Finally, a complete detection report is issued, providing an important basis for formulating a repair plan. Step S2: Calculate and evaluate the degree of pipeline damage. Based on the pipeline operation risk level assessment, it is divided into three levels: low, medium, and high, to determine the trenchless pipeline repair method to be used. Step S3: Determine the pipe specifications for repair based on the required water flow and pressure, and repair the pipe using the appropriate repair method; specifically, this includes the following steps: The pipeline repair method is determined based on the pipeline operation risk assessment level and pipeline type. Drainage pipelines with high operation risk levels are repaired using an expansion joint plus short pipe insertion method, while water supply pipelines with high operation risk levels are directly refurbished without repair. The repair method using an expansion joint plus short pipe insertion method includes first determining the short pipe specifications; the pipe wall thickness is calculated using the following formula: （3） In the formula, t represents the inner lining wall thickness, 0.721 represents a coefficient, C represents the ellipticity reduction factor, and N represents the safety factor. Indicates the original inner diameter of the pipe. The total external pressure of the pipeline is represented by EL, the long-term elastic modulus of the short pipe is represented by RW, the buoyancy coefficient is represented by B', and the elastic support coefficient is represented by B'. This indicates the overall deformation modulus of the soil along the pipe. After determining the specifications of the short pipe, the short pipe insertion process is carried out to complete the bursting of the original pipe and the installation of the short pipe. Drainage and water supply pipes with medium operational risk levels are repaired using flexible hose lining. This repair method requires that the lining pipe be able to withstand external groundwater pressure, vacuum pressure, and the internal water pressure at the damaged section of the original pipe. The formula for calculating the lining pipe wall thickness is as follows: （4） In the formula, t represents the wall thickness of the inner lining pipe, Do represents the outer diameter of the inner lining pipe, and K represents the circumferential support ratio. C represents the long-term elastic modulus of the inner liner tube, and C represents the ellipticity reduction factor. This indicates the groundwater pressure at the top of the inner lining pipe. The value represents the vacuum pressure, N represents the circumferential stability resistance coefficient of the pipe cross section, and μ represents Poisson's ratio, which is determined according to the lining material. After determining the specifications of the inner lining hose, a working pit is excavated, the interior of the original pipeline is pre-treated, the new inner lining hose is pulled using the existing inspection well and working pit, and finally the pipeline is connected. Drainage pipes with low operational risk levels are repaired using a spraying method, while water supply pipes with low operational risk levels are repaired using an ultraviolet light curing method. The repair method using spraying includes: Place the spraying equipment on one side of the pipe to be repaired. The longitudinal axis of the spraying equipment and the longitudinal axis of the pipe to be repaired should be on the same straight line. Before spraying, drag the umbilical tube into place and install the nozzle at the front end of the umbilical tube. Select the nozzle according to the inner diameter of the pipe to be repaired. Use the pipe spraying robot to spray the defect location of the pipe. Spray two to three times, with each spray thickness being 1.2mm-2.75mm. The time interval between each spray is 90-120 minutes. The repair method using ultraviolet light curing includes: The calculation method for the total thickness of the pipe impregnation resin and hose is the same as that for the hose lining method. After determining the thickness of the impregnation resin and hose, the upstream pipe is first sealed, then the pipe is dredged, a gasket is pre-installed in the cleaned pipe, the resin-impregnated hose is pulled into the original pipe along the gasket, the resin tube is inflated to make the resin tube fully adhere to the original pipe, and the hose material is cured by irradiating it with a special wavelength of ultraviolet light. Finally, the pressure is reduced to complete the repair. Step S4: After repair, detect and verify whether the repair effect is qualified.

2. The trenchless pipeline repair method according to claim 1, characterized in that, The calculation of the pipeline damage degree includes: Classify pipeline defects into structural defects and functional defects, classify structural defects and functional defects respectively, and define the grade defect influence coefficient and defect score of the corresponding pipeline defects; then determine the pipeline defect score according to the pipeline defect condition assessment score calculation formula. The pipeline defect condition assessment score calculation formula is as follows: （1） In the formula, L represents the total length of the pipeline being evaluated. This represents the longitudinal distance length of the i-th defect. This represents the defect score of the i-th defect. The defect length coefficient represents the i-th defect, and n represents the total number of defects; Define 3 defect grades according to the pipeline defect condition assessment score. When the assessment score S≥7, it is grade III; when 4≤S<7, it is grade II; when S<4, it is grade I. Determine the failure consequence risk assessment score coefficient and failure consequence weight, calculate the pipeline failure consequence risk assessment score, and define 3 failure consequence risk grades of grade I, grade II, and grade III according to the failure consequence assessment score. The pipeline failure consequence risk assessment score calculation formula is: （2） In the formula, This represents the risk assessment score coefficient for the i-th failure consequence. Indicates the first The risk assessment weight for failure consequences, where n represents the total number of failure consequence assessments; The 3 defect grades defined according to the failure consequence assessment score are: when R≥7, it is grade III; when 4≤R<7, it is grade II; when R<4, it is grade I. Evaluate the pipeline operation risk grade according to the combination of the pipeline defect grade and the failure consequence risk grade, which is divided into three levels: low, medium, and high.

3. The trenchless pipeline repair method according to claim 2, characterized in that... , The evaluation of the pipeline operation risk grade according to the combination of the pipeline defect grade and the failure consequence risk grade includes: Low-level operation risk is the combination of grade I pipeline defect and grade I failure risk grade, the combination of grade I pipeline defect and grade II failure risk grade, and the combination of grade II pipeline defect and grade I failure risk grade; Medium-level operation risk is the combination of grade II pipeline defect and grade II failure risk grade, and the combination of grade I pipeline defect and grade III failure risk grade; High-level operation risk is the combination of grade II pipeline defect and grade III failure risk grade, the combination of grade III pipeline defect and grade I failure risk grade, the combination of grade III pipeline defect and grade II failure risk grade, and the combination of grade III pipeline defect and grade III failure risk grade.

4. The trenchless pipeline repair method according to claim 1, characterized in that, The detection and verification after repair to determine whether the repair effect is qualified includes: After the repair operation of the non-pressure pipeline is completed, put the CCTV detection robot into the new pipeline for inspection, and then conduct the water tightness test for the non-pressure pipeline. After the test pipe section is filled with water, the soaking time should not be less than 24 hours. Start timing when the test water head reaches the specified water head, observe the water seepage volume of the pipeline, continuously replenish water into the test pipe section to keep the test water head constant until the observation ends. When the water leakage volume meets the specification requirements, the water tightness test of the pipeline is qualified; After the repair of the pressure pipeline is completed, use the CCTV robot to inspect and accept the internal appearance quality of the pipeline again, conduct a sectional water tightness pressure test on the pipeline, and conduct a water tightness pressure test on each branch pipe to ensure that there is no water leakage in the pipeline; The process of the water tightness test for the non-pressure pipeline is that the water tightness test of the pipeline should be carried out according to the standard specifications. When the water leakage volume meets the specification requirements, the water tightness test of the pipeline is qualified. The formula for the measured water seepage volume is （15） In the formula, q is the measured water seepage volume, W is the water replenishment volume, T is the actual water seepage observation time, and L is the length of the test pipe section.

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