A trench support state classification compensation method and system before commissioning of a long-distance pipeline

Abstract

The present application relates to long pipeline construction and maintenance technical field, especially a kind of long pipeline before commissioning ditch support state classification compensation method and system, the method comprises: presetting pipe body survey line, ditch bottom reference survey line and grid arc supporting compensation unit in ditch compensation subarea;Strain, temperature and ditch bottom reference survey line data of pipe body are obtained, and reference strain is obtained;Pipe body strain is corrected to reference, and corrected strain is obtained;Load curvature increment and pressure maintaining duration change component, back fall recovery component are calculated;Ditch support state is classified into different support states;According to different support states, execute different compensation scheme, and dynamically calculate load curvature recovery rate and adjacent subarea response transfer amount;After compensation, recovery load level is carried out retest, and compensation effect and adjacent subarea response are reviewed, and after passing, output construction file.The present application realizes ditch support state quantification classification and different compensation by water pressure test, and retest forms closed loop quality control.

Description

Technical Field

[0001] This invention relates to the field of long-distance pipeline construction and maintenance technology, and in particular to a method and system for classifying and compensating for trench support status before long-distance pipelines are put into operation. Background Technology

[0002] After the long-distance pipeline is laid in the trench and initially backfilled, a hydrostatic test needs to be carried out. In traditional processes, the hydrostatic test is only used to verify the pressure-bearing capacity of the pipe body, circumferential welds and supporting valves. The controlled load changes brought about by the entire process of loading, holding pressure and falling back, and the corresponding pipe body bending response have not been fully utilized for the identification and treatment of pipeline support defects. Existing pipeline deformation and support defect monitoring methods are mostly deployed for the operation period, and the treatment methods focus on solving local foundation bearing capacity problems. The two types of technologies are independent of each other and have not formed a closed-loop system in the pre-production process window.

[0003] However, existing technologies still have significant shortcomings in the pre-commissioning construction process window: 1. Existing monitoring schemes do not connect to the controlled loading window of the hydrostatic test. Anomalies such as loose or voided supports and hard spots in the trench are usually only discovered after final reshaping, backfilling, and topography restoration. At this point, rework and excavation costs are high, construction is difficult, and it is easy to delay the commissioning plan. 2. Existing schemes mostly use a single strain threshold to determine anomalies, which cannot distinguish between different defect types such as loose or voided supports, local hard spot supports, and overall foundation disturbance, which can easily lead to blind grouting. 3. Conventional grouting processes lack segmentation constraints, and compensation materials can easily diffuse randomly along the pipeline axis, causing bending stress to transfer to adjacent zones, making it difficult to achieve precise point support; moreover, the effect is not verified under the same hydrostatic loading conditions after compensation, and the risk of bending stress transfer to adjacent zones caused by local compensation is not considered, which poses safety hazards such as over-injection of the top-damaged anti-corrosion layer and secondary transfer of defect response.

[0004] Therefore, there is an urgent need for a solution that relies on hydrostatic testing to classify the support status of pipe trenches, provide differentiated compensation, and conduct closed-loop verification, so as to achieve precise control over the quality of pipe trench supports before commissioning. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for classifying and compensating for trench support conditions before the commissioning of long-distance pipelines.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for classifying and compensating for trench support conditions before the commissioning of a long-distance pipeline. The method includes the following steps: pre-arranging pipe body survey lines, trench bottom reference survey lines, and segmented arc-shaped support compensation units within a trench compensation zone; acquiring the original strain, pipe body temperature, and trench bottom reference survey line data of the pipe body survey lines, and preprocessing the trench bottom reference survey line data to obtain a reference strain; performing a reference correction on the pipe body strain based on the original strain, the reference strain, and the pipe body temperature to obtain a corrected strain; and calculating based on the corrected strain... The loading curvature increment is used to calculate the pressure holding continuous change component and the fallback recovery component. Combining the loading curvature increment, the pressure holding continuous change component, and the fallback recovery component, the trench support state is classified into different support states. Differentiated compensation schemes are executed according to the different support states. During the compensation process, the loading curvature recovery rate and the response transfer amount of adjacent zones are dynamically calculated based on the loading curvature increment. After the compensation is completed, the system is restored to the corresponding test loading level or at least one retest loading level to conduct a retest, verify the compensation effect and the response of adjacent zones, and output the construction file after passing the test.

[0007] This invention utilizes the hydrostatic test window period to complete the measurement line acquisition, state classification, difference compensation, and re-inspection closed loop after preliminary backfilling and before final backfilling, thereby achieving quantitative identification and precise handling of trench support defects before commissioning.

[0008] Optionally, the step of pre-arranging pipe body survey lines, trench bottom reference survey lines, and segmented arc-shaped support compensation units within the trench compensation zone includes: setting the segmented arc-shaped support compensation unit as an arc-shaped flexible bag and an inter-cell isolation strip arranged along the pipe axis, wherein the inter-cell isolation strip divides the arc-shaped flexible bag into compensation cells that do not cross-contaminate or restrict cross-contamination, and an injection channel and an exhaust or return channel are provided in the compensation cell; the pipe body survey lines, the trench bottom reference survey lines, and the segmented arc-shaped support compensation units are pre-positioned in the trench compensation zone before, during, or before initial backfilling.

[0009] This invention enables precise single-point injection, preventing uncontrolled diffusion of compensation materials.

[0010] Optionally, the corrected strain at the i-th trench compensation zone, the m-th test loading level, and the c-th pipe body survey line orientation... Represented as: ; in, For the original strain of the tube, The reference strain is the strain after deducting the influence of the temperature change of the reference survey line at the bottom of the trench and the calibration of the burial position. This is the tube body temperature correction factor. For tube body temperature, This is the initial temperature.

[0011] This invention eliminates the effects of overall disturbance, instrument drift, and temperature, and obtains a corrected strain that only reflects local bending, thereby improving the accuracy of discrimination.

[0012] Optionally, the loading curvature increment Calculate using the following formula: ; in, and These represent the corrected pipe top and pipe bottom strains under the i-th trench compensation zone and the m-th test loading level, respectively. and These represent the corrected pipe top and pipe bottom strains of the i-th trench compensation zone in the initial state. This refers to the outer diameter of the tube.

[0013] This invention directly quantifies the local bending response of each partition under experimental loading, providing a unified index for modeling.

[0014] Optionally, the pressure holding component continuously varies. and the fallback recovery component Calculated using the following formula: ; ; in, and These represent the start time of the pressure holding test at the i-th trench compensation zone and the m-th test loading level, respectively. and the end of the pressure holding time The loading curvature increment, To maintain pressure for a certain period of time, and These represent the increments of loading curvature before and after the fallback, respectively, for the i-th trench compensation zone and the m-th test loading level. is the curvature regularization constant.

[0015] The pressure holding continuous change component calculated by this invention can identify continuous deformation under constant load, and the fallback recovery component can determine the degree of recovery after unloading, effectively distinguishing between loose voids and continuous support states.

[0016] Optionally, the trench support state is classified into different support states by combining the loading curvature increment, the pressure holding continuous change component, and the fallback recovery component. This includes: the trench support state is further classified by combining at least one of the left-right strain asymmetry, adjacent zone difference, reference synchronization degree, and pipe lifting response; when the loading curvature increment, the pressure holding continuous change component, and the adjacent zone difference exceed corresponding limits, and the fallback recovery component is below the corresponding limit, the state is classified as loose or detached support; when the left-right strain asymmetry or the pipe lifting response exceeds the corresponding limit, or when the loading curvature increment sign is opposite to the expected bending direction and the adjacent zone difference exceeds the corresponding limit, the state is classified as locally hardened support; when the reference synchronization degree shows that the trench bottom reference line changes synchronously with the bending response of multiple adjacent zones, the state is classified as overall disturbance; when all indicators are within allowable limits, the state is determined to be continuous support.

[0017] This invention enables automatic differentiation of four types of trench support states, providing a basis for decision-making on differentiated treatment.

[0018] Optionally, the implementation of differentiated compensation schemes based on different support states includes: for zones with loose or voided support states, selecting at least one compensation cell according to the abnormal location to inject low-shrinkage compensation material, and executing stop injection control based on injection pressure, venting or backflow status, the loading curvature recovery rate, pipe lifting response, and the response transfer amount of adjacent zones during the injection process; for zones with local hard point support states, prohibiting the injection of the low-shrinkage compensation material, and outputting excavation verification, hard point removal, or soft pad adjustment instructions; for zones with overall disturbance states, prioritizing the verification of the trench bottom baseline, pressure test loading records, and ambient temperature, not directly executing the compensation cell injection, and outputting overall treatment suggestions.

[0019] Based on the classification results, this invention implements different compensation measures for different trench support states to avoid mis-injection and ineffective construction, and achieve targeted treatment.

[0020] Optionally, the loading curvature recovery rate and the adjacent partition response transfer amount Determine by the following formula: ; ; in, and These represent the increments of loading curvature before and after compensation in the i-th trench compensation zone under the same experimental loading level. , , , These represent the loading curvature increments of the left and right adjacent zones before and after compensation for the i-th trench compensation zone. , is the curvature regularization constant.

[0021] This invention quantifies the compensation effect of this partition by the loading curvature recovery rate and monitors the impact of neighboring partitions by the response transfer amount of adjacent partitions. The two together constitute the basis for determining the suspension and review, preventing compensation from causing new stress concentration.

[0022] Optionally, the verification of the compensation effect and the response of adjacent zones, after passing the verification, outputs the construction file, including: recalculating and verifying the loading curvature recovery rate, the response transfer amount of adjacent zones, the loading curvature increment and the pipe lifting response, and outputting the shaping and backfilling ready status, the pre-production verification status and the construction file after the verification conditions are met.

[0023] This invention forms a traceable closed-loop quality control system by restoring the system to the test loading level or retest loading level after compensation.

[0024] Secondly, this invention provides a trench support state classification compensation system before the commissioning of a long-distance pipeline. The system executes the trench support state classification compensation method provided by this invention. The system includes an input device, an output device, a processor, and a memory, all interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to call these program instructions. This invention achieves automated operation of data acquisition, benchmark correction, state classification, compensation control, and verification judgment through the processor executing the program instructions. Attached Figure Description

[0025] Figure 1 This is a flowchart of a trench support state classification compensation method for a long-distance pipeline before commissioning, according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the segmented arc-shaped support compensation unit and the arrangement of measuring lines according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the support state response under multiple test loading levels in the hydrostatic test according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the differentiated compensation scheme and post-compensation retest in an embodiment of the present invention.

[0029] Figure 5 This is a framework diagram of a trench support state classification compensation system for a long-distance pipeline before commissioning, according to an embodiment of the present invention. Detailed Implementation

[0030] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.

[0031] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.

[0032] Please see Figure 1 One embodiment of the present invention provides a method for classifying and compensating for the trench support status before the commissioning of a long-distance pipeline, the method comprising the following steps: S1. Pre-arrange pipe body survey lines, trench bottom benchmark survey lines, and segmented arc-shaped support compensation units within the pipe trench compensation zone.

[0033] In this embodiment, before, during, or before initial backfilling of the long-distance pipeline section to be put into operation, trench compensation zones are defined along the pipeline axis. Specifically, trench compensation zones can be defined by fixed length or by increasing the density of risk points. Specifically, short zones are set on both sides of the circumferential weld, with continuous measuring lines passing through the top and bottom of the pipe to accurately identify discontinuous support responses near the weld; independent zones are set before and after the boundary line at the junction of soft and hard foundations to distinguish between sudden changes in foundation stiffness, localized loose supports, and overall settlement disturbances; denser zones are set outside the rigid structure at the valve chamber inlet / outlet section, while retaining ground joints to reduce stress concentration and identification errors in the transition section between the structure and the ordinary trench; left and right measuring lines are added at elbows or cold-bent pipe locations to identify asymmetrical support anomalies such as lateral deviation and localized hard points.

[0034] For further details, please refer to Figure 2The pipe body survey lines, trench bottom benchmark survey lines, and segmented arc-shaped support compensation units are pre-installed before, during, or before initial backfilling. After initial backfilling or temporary covering that meets the safety requirements of the hydrostatic test is completed, they are then connected to the ground exit ends of the survey lines and segmented arc-shaped support compensation units. The pipe body survey lines include, but are not limited to, distributed optical fibers, fiber optic gratings, strain gauge strings, flexible strain bands, or equivalent sensing lines, and are fixed to the pipe body surface along the pipe axis. The trench bottom benchmark survey lines are set in the bedding layer, trench bottom shoulder, or adjacent soil within the same trench compensation zone, and have corresponding mileage points with the pipe body survey lines, but do not share fixed points with the pipe body. Their function is to record temperature, overall surface disturbance, and instrument drift, not as pipe body survey lines.

[0035] The segmented arc-shaped support compensation unit is installed in the pre-set support arc area on the lower side of the pipe body, typically covering the five o'clock to seven o'clock position of the pipe body. It can also be adjusted to the corresponding angle range below and on the lower side of the pipe body according to actual project needs. This unit includes, but is not limited to, an arc-shaped flexible bag, an anti-corrosion isolation pad, a pressure distribution layer, inter-cell isolation strips, a double-pipe interface seat, an injection channel, an exhaust or return channel, and a check valve.

[0036] The outer arc surface of the curved flexible bag faces the bottom cushion layer or undisturbed soil, while the inner arc surface faces the lower side of the pipe. The anti-corrosion isolation pad is placed between the anti-corrosion layer of the pipe and the curved flexible bag, and is laid continuously or in sections along the lower support arc area of ​​the pipe. Flexible rubber pads, polyethylene protective sheets, or geotextile protective layers can be used to isolate the compensation unit from the anti-corrosion layer of the pipe and prevent the anti-corrosion layer from being damaged by compression. The pressure distribution layer is located on the side of the curved flexible bag close to the pipe. Flexible reinforcing sheets, rubber sheets, geocell sheets, or fiber-reinforced composite sheets can be used to transform the point contact support after the compensation material has been cured into a uniform arc surface support, so that the contact pressure after injection is evenly distributed along the arc support surface.

[0037] Inter-cell isolation strips are used to limit the uncontrolled diffusion of low-shrinkage compensation material and prevent the formation of excessively long hardened supports due to single-point injection. These isolation strips can take the form of transverse diaphragms, heat-sealed edges, adhesive strips, or stitched strips, dividing the arc-shaped flexible bag into multiple compensation cells along the pipeline axis, ensuring either no cross-contamination of the material or limited cross-contamination. The edges of the isolation strips are sealed to the perimeter of the bag, and their pressure-bearing capacity is set at a level not lower than the maximum allowable injection pressure of the corresponding compensation cell. Optionally, flow-limiting holes can be opened on the isolation strips to allow adjacent compensation cells to connect slowly only during the low-pressure equalization phase.

[0038] Each compensation cell has at least one injection channel and one venting or return channel. The injection channel is used to connect the low-shrinkage compensation material, and the venting or return channel is used to drain air, water, or return slurry from the compensation cell. The bag port of the injection channel is preferably located at the lower or lower side of the compensation cell, and the bag port of the venting or return channel is preferably located at the higher or upper side of the compensation cell. Both are led to the ground marking connector via a double-pipe interface. The ground marking connector is retained until the final shaping backfill and topography restoration process to facilitate fixed-point injection, injection stop verification, and post-compensation re-inspection. A check valve is used to prevent the injected low-shrinkage compensation material from flowing back.

[0039] In addition to meeting volume stability requirements, the equivalent compressive modulus of low-shrinkage compensation materials after curing should match the compressive modulus of the original cushion layer, replacement material, or adjacent foundation. Specifically, it should not be lower than the lower limit required for restored support, nor higher than the upper limit or a multiple of the upper limit of the modulus of the surrounding support materials set for the project. This range can be determined through indoor test blocks, on-site mixing, light dynamic penetration tests, plate load tests, or design-given values ​​to avoid the formation of new rigid support points after compensation.

[0040] During the initial injection phase, the venting or return channel remains open to expel air, water, or slurry from the compensation cell. Once the return channel exhibits continuous and stable slurry return, stable back pressure, or reaches the set return flow rate, it is throttled or closed, and the pressure-holding observation phase begins. If there is prolonged absence of return flow, sudden cessation of return flow, or abnormally high injection pressure, injection is stopped, and the compensation cell is checked for blockages, hard points causing pressure buildup, or channel failure.

[0041] S2. Obtain the original strain, pipe temperature and trench bottom baseline measurement data of the pipe body measurement line, and preprocess the trench bottom baseline measurement data to obtain the baseline strain.

[0042] In this embodiment, after the initial backfilling or temporary covering that meets the safety requirements of the hydrostatic test, and before the final shaping backfilling and landform restoration, the original strain, pipe temperature, and trench bottom baseline data are acquired under multiple test loading levels of the hydrostatic test. Specifically, the hydrostatic test uses key conditions such as completion of water filling, pressure increase to several proportional nodes of the test pressure, pressure holding start, pressure holding stabilization, pressure drop, and retest loading as test loading levels. At each test loading level, the test pressure, water filling status, pressure holding time, pipe temperature, original pipe strain, and original readings of the trench bottom baseline are simultaneously collected and recorded.

[0043] After the monitoring units are deployed, in-situ calibration is conducted during the zero-load static stage before the hydrostatic test to obtain benchmark calculation parameters for subsequent pipe strain correction. For different benchmark survey line installation locations, such as the subgrade, trench bottom shoulder, and adjacent soil, continuous support zones or field calibration sections without anomalies are selected. Response data of the pipe survey line and the trench bottom benchmark survey line are collected simultaneously. Based on the proportional relationship between the overall pipe response and the benchmark response, the position calibration coefficient for the corresponding installation location is determined. Simultaneously, temperature data of the benchmark survey line is collected, and the interference caused by temperature strain is deducted based on the temperature coefficient of the benchmark survey line itself. Finally, the benchmark reading after deducting the temperature influence is multiplied by the corresponding position calibration coefficient to obtain the benchmark strain after dual calibration by temperature correction and installation location. If multiple benchmark points are set within the same zone, the benchmark point data with the smallest calculated residual can be selected, or a multi-point weighted combination method can be used to determine the benchmark strain for that zone.

[0044] The reference strain obtained through the above calibration can effectively eliminate systematic errors caused by temperature drift of the reference measurement line itself and differences in the burial position, avoid misjudging such interference as local bending deformation of the pipe body, and provide a reliable reference basis for subsequent pipe body strain correction and support state classification.

[0045] S3. Based on the original strain, the reference strain, and the tube temperature, the tube strain is corrected to obtain the corrected strain.

[0046] In this embodiment, the corrected strain at the i-th trench compensation zone, the m-th test loading level, and the c-th pipe body survey line orientation is... Represented as: ; in, For the original strain of the tube, The reference strain is the strain after deducting the influence of the temperature change of the reference survey line at the bottom of the trench and the calibration of the burial position. This is the tube body temperature correction factor. For tube body temperature, This is the initial temperature.

[0047] S4. Calculate the loading curvature increment based on the corrected strain, and calculate the pressure holding continuous change component and the fallback recovery component based on the loading curvature increment.

[0048] In this embodiment, the pressure holding continuous change component is calculated based on the loading curvature increment during the pressure holding phase of the hydrostatic test, and the fallback recovery component is calculated based on the loading curvature increment during the fallback phase of the hydrostatic test.

[0049] Specifically, the loading curvature increment Calculate using the following formula: ; in, and These represent the corrected pipe top and pipe bottom strains under the i-th trench compensation zone and the m-th test loading level, respectively. and These represent the corrected pipe top and pipe bottom strains of the i-th trench compensation zone in the initial state. This refers to the outer diameter of the tube.

[0050] The loading curvature increment is used to describe the local bending response of the same trench compensation zone under hydraulic test loading. For zones at the junction of soft and hard foundations, backfill boundaries, or where the foundation stiffness changes significantly, the loading curvature increment can be used as an observation and normalized in conjunction with an elastic foundation beam model. Specifically, the allowable curvature response of the zone under the same test loading level is determined using the pipe bending stiffness, zone length, and equivalent foundation reaction coefficient obtained from design, testing, or field back-calculation. The measured loading curvature increment is then compared with the allowable curvature response to obtain the normalized bending response index. The subsequent pressure holding continuous change component, fallback recovery component, loading curvature recovery rate, and response transfer amount of adjacent zones can be calculated uniformly using the loading curvature increment or the normalized bending response index, but the same calculation caliber should be maintained within the same pipe section.

[0051] To avoid using only a single threshold for judgment, this embodiment also calculates the component of continuous pressure variation. and the recovery component : ; ; in, and These represent the start time of the pressure holding test at the i-th trench compensation zone and the m-th test loading level, respectively. and the end of the pressure holding time The loading curvature increment, To maintain pressure for a certain period of time, and These represent the increments of loading curvature before and after the fallback, respectively, for the i-th trench compensation zone and the m-th test loading level. is the curvature regularization constant, used to keep the calculation stable when the denominator is close to zero.

[0052] S5. Combining the loading curvature increment, the pressure holding continuous change component, and the fallback recovery component, the trench support state is classified into different support states.

[0053] In this embodiment, the trench support state is classified based on the loading curvature increment, the continuous pressure holding change component, and the fallback recovery component, combined with at least one of the following: left and right side strain asymmetry, adjacent zone difference, reference synchronization degree, and pipe lifting response. Please refer to [link to relevant documentation]. Figure 3 When the loading curvature increment, the continuous change component of the holding pressure, and the difference between adjacent zones exceed the corresponding limits, and the fallback recovery component is lower than the corresponding limit, the classification is a loose or detached support state; when the strain asymmetry on the left and right sides or the pipe lifting response exceeds the corresponding limit, or when the sign of the loading curvature increment is opposite to the expected bending direction and the difference between adjacent zones exceeds the corresponding limit, the classification is a local hard point support state; when the benchmark synchronization degree shows that the bending response of the trench bottom benchmark line changes synchronously with that of multiple adjacent zones, the classification is an overall disturbance state; when all indicators are within the allowable limits, it is determined to be a continuous support state.

[0054] The above classification indicators are all derived from the same hydrostatic test loading level or the same pressure-holding sampling window. Among them, the left-right strain asymmetry is used to determine if there is pipe jacking deviation; the adjacent zone difference is used to determine if the anomaly is limited to a single trench compensation zone; the benchmark synchronization degree is used to determine if the change in the trench bottom benchmark line is synchronized with multiple adjacent zones; the pipe jacking response is preferentially obtained from displacement measuring points, and if no displacement measuring points are set, it can be calculated as the equivalent jacking amount from the pipe strain. The calculation formulas for each indicator are as follows: ; ; , ; ; ; in, This represents the asymmetry in strain between the left and right sides. This indicates the target test loading level or the same holding pressure sampling window used for classification. , , and These are the corrected strains for the left, right, top, and bottom measuring lines of the i-th trench compensation zone, respectively. All values ​​are the corrected values ​​from the aforementioned benchmark, not the original measured strains. This represents the difference between neighboring areas. , and These represent the loading curvature increments of the i-th trench compensation zone and its left and right adjacent zones, respectively. As a benchmark for synchronization, Let i be the set of partitions adjacent to the i-th trench compensation partition. The formula represents the correlation coefficient between the trench bottom baseline change sequence of the i-th trench compensation zone and the loading curvature increment sequence of the j-th adjacent zone within the same sampling window. Here, avg represents the correlation coefficient between the sets of adjacent zones. The internal correlation coefficient is taken as the arithmetic mean. The pipe lifting response is obtained from the displacement measuring point. Let be the vertical displacement of the i-th trench compensation zone at time t. For the initial displacement, when no displacement measuring points are set, it can be used As an equivalent lifting amount For strain-displacement conversion factor, Let represent the length of the i-th trench compensation zone. and is the regularization constant.

[0055] It should be noted that the limits for curvature, pressure holding change, fallback recovery, left-right asymmetry, jacking response, adjacent zone transfer, recovery rate, and adjacent zone difference can be derived from anomaly-free zones under the same pipe diameter, wall thickness, and backfill conditions, or from baseline sections before testing, enterprise acceptance requirements, construction simulation sections, or design-given limits. The source of these limits is determined by the engineering approach and can be determined before construction based on the project's acceptance criteria.

[0056] S6. Execute differentiated compensation schemes according to the different support states. During the compensation process, dynamically calculate the loading curvature recovery rate and the response transfer amount of adjacent partitions based on the loading curvature increment.

[0057] In this embodiment, please refer to Figure 4 For loose or voided supports, select one or more compensation cells according to the abnormal location and inject low-shrinkage compensation material. Injection can be performed after the target loading level data is collected, the pressure is stable, and construction safety conditions are met, or it can be injected after the pipe section pressure drops to the allowable construction pressure. Low-shrinkage compensation materials include, but are not limited to, low-shrinkage cement-based grout, pumpable fluidized solidified filler, foamed lightweight soil grout, micro-expansion mortar, or combinations thereof. The material should consider pumpability, post-curing strength, volume stability, and corrosion protection.

[0058] During the injection process, the injection pressure, injection volume, venting or recirculation status, and pipe strain are recorded simultaneously. The loading curvature recovery rate, pipe lifting response, and adjacent zone response transfer are calculated. Among these, the loading curvature recovery rate... and adjacent partition response transfer amount Determine by the following formula: ; ; in, and These represent the increments of loading curvature before and after compensation in the i-th trench compensation zone under the same experimental loading level. , , , These represent the loading curvature increments of the left and right adjacent zones before and after compensation for the i-th trench compensation zone. , is the curvature regularization constant.

[0059] Injection should not be stopped solely based on the injection volume. Injection should preferably be stopped when the following conditions are met simultaneously: the injection pressure is stable and does not exceed the smaller of the pipe body's allowable jacking pressure, the pipe body's allowable contact pressure with the anti-corrosion coating, and the stable pressure on the trench sidewall; the venting or return channel changes from continuous venting / drainage to stable slurry discharge or stable back pressure; the loaded curvature recovery rate reaches the recovery rate limit; the pipe body's jacking response does not exceed the jacking response limit; and the response transfer amount between adjacent zones does not exceed the adjacent zone transfer limit.

[0060] It should be noted that the sources of the above-mentioned allowable pressure include pipe design documents, allowable ellipticization or jacking calculations corresponding to pipe material and wall thickness, allowable contact pressure or on-site indentation test results provided by the pipe anti-corrosion layer manufacturer, trench slope stability calculations, temporary backfill thickness, and construction safety plans. In actual control, the smaller value among the above allowable values ​​should be used, and real-time limits should be imposed in conjunction with the pressure gauge or pressure sensor of the injection equipment.

[0061] For localized hard-point support conditions, the system outputs a "no injection" status, allowing for excavation verification, hard point removal, adjustment of the soft cushion, or re-leveling of the cushion layer. For overall disturbance conditions, the system prioritizes verifying the trench bottom baseline, test loading records, and ambient temperature. If the overall disturbance is confirmed to be a genuine foundation problem, rather than interference from temperature, instruments, or the test process, the system will not directly execute individual compensation cell injection. Instead, it will output overall treatment recommendations, including but not limited to expanding the verification scope, suspending reshaping and backfilling, re-leveling or compacting the cushion layer, local replacement, resetting continuous arc supports, or requiring the design unit to verify the foundation treatment plan. After overall treatment is completed, a re-verification at the same loading level is performed. Only when residual local anomalies meet the conditions for loose or voided supports will segmented compensation be initiated.

[0062] Furthermore, no new state categories are added for composite working conditions; instead, they are handled according to risk priority. When the same area simultaneously meets the conditions of loose or voided support and local hard point support, injection is prohibited first for the local hard point support state, and excavation verification or soft pad adjustment is performed. If loose or voided support characteristics still exist after verification, then segmented compensation is performed. When the overall disturbance state and local anomaly occur simultaneously, the overall disturbance is dealt with first. After the baseline synchronous change is eliminated, compensation is then performed on the remaining local anomaly zones.

[0063] S7. After the compensation is completed, the test shall be resumed at the corresponding test loading level or at least one re-inspection loading level to re-inspect, recheck the compensation effect and the response of adjacent partitions, and output the construction file after passing the qualification.

[0064] In this embodiment, after compensation, the re-inspection shall be carried out at the corresponding test loading level or at least one re-inspection loading level. When the loading curvature recovery rate is greater than the recovery rate limit, the compensated loading curvature increment does not exceed the curvature limit, the response transfer amount of adjacent partitions does not exceed the adjacent area transfer limit, and the pipe jacking response does not exceed the range of the jacking response limit, the recheck is determined to be qualified. If the response transfer amount of adjacent partitions exceeds the adjacent area transfer limit, stop continuous injection in the current partition, reclassify adjacent partitions, reduce material stiffness, expand the compensation range, adjust the order of compensation grids or conduct excavation recheck if necessary.

[0065] After meeting the recheck conditions, the shaping and backfilling ready state, the pre-commissioning recheck state and the construction file shall be output. The construction file includes but is not limited to partition numbers, material batches, injection volume, re-inspection curves, injection prohibition reasons and disposal suggestions.

[0066] Please refer to Figure 5 , in an alternative embodiment, the present invention provides a divisional compensation system for trench support state before commissioning of a long-distance pipeline, the system comprising an input device, an output device, a processor and a memory, wherein the hardware facilities are connected to each other, the memory is configured to store a computer program, the computer program comprises program instructions, and the processor is configured to call the program instructions to execute the specific steps of the embodiments related to the divisional compensation method for trench support state before commissioning of a long-distance pipeline provided by the present invention. The divisional compensation system for trench support state before commissioning of a long-distance pipeline provided by the present invention has a complete structure and stable operation, which improves the overall applicability and practical application capability of the present invention.

[0067] In conclusion, the beneficial effects of the present invention include: 1. By utilizing the loading, pressure maintaining and pressure falling processes of the hydraulic test, the controlled loading verification of the trench support state is realized before commissioning without changing the safety boundary of the hydraulic test itself; 2. Through response classification in the three stages of loading, pressure maintaining and pressure falling, different support problems such as looseness or void, hard points and overall disturbance are distinguished, reducing simple threshold alarms and blind grouting; 3. Fixed-grid injection, exhaust backflow and anti-corrosion layer isolation are realized through the divided arc-shaped support compensation unit, so that the compensation action has a clear device carrier; 4. By rechecking the compensation effect and the response of adjacent partitions, the risks of over-compensation, local jacking and strain transfer between adjacent partitions are reduced; 5. Output the shaping and backfilling, pre-commissioning recheck status and construction files, so that the detection results, compensation actions and recheck records can be corresponding to specific partitions and compensation grids.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for classifying and compensating for trench support conditions before the commissioning of a long-distance pipeline, characterized in that, Includes the following steps: Pipeline survey lines, trench bottom baseline survey lines, and segmented arc-shaped support compensation units are pre-arranged within the trench compensation zone. The original strain, pipe temperature, and trench bottom baseline measurement data of the pipe body measurement line are obtained, and the trench bottom baseline measurement data are preprocessed to obtain the baseline strain. Based on the original strain, the reference strain, and the tube temperature, the tube strain is corrected to obtain the corrected strain. The corrected strain at the i-th trench compensation zone, the m-th test loading level, and the c-th pipe body survey line orientation Represented as: ； in, For the original strain of the tube, The reference strain is the strain after deducting the influence of the temperature change of the reference survey line at the bottom of the trench and the calibration of the burial position. This is the tube body temperature correction factor. For the tube body temperature, The initial temperature; The loading curvature increment is calculated based on the corrected strain, and the pressure holding continuous change component and the fallback recovery component are calculated based on the loading curvature increment. Combining the loading curvature increment, the pressure holding continuous change component, and the fallback recovery component, the trench support state is classified into different support states; Differentiated compensation schemes are executed according to the different support states. During the compensation process, the loading curvature recovery rate and the response transfer amount of adjacent partitions are dynamically calculated based on the loading curvature increment. After compensation is completed, the system is restored to the corresponding test loading level or at least one retest loading level to conduct a retest, verify the compensation effect and the response of adjacent zones, and output the construction file after passing the test.

2. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The pre-arrangement of pipe body survey lines, trench bottom benchmark survey lines, and segmented arc-shaped support compensation units within the trench compensation zone includes: The segmented arc-shaped support compensation unit consists of an arc-shaped flexible bag and inter-cell isolation strips arranged along the pipeline axis. The inter-cell isolation strips divide the arc-shaped flexible bag into compensation cells that prevent cross-contamination of slurry or limit cross-contamination of slurry. Injection channels and venting or return channels are provided in the compensation cells. Before, during, or before initial backfilling, the pipe body survey line, the trench bottom reference survey line, and the segmented arc-shaped support compensation unit are pre-installed in the trench compensation zone.

3. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The loading curvature increment Calculate using the following formula: ； in, and These represent the corrected pipe top and pipe bottom strains under the i-th trench compensation zone and the m-th test loading level, respectively. and These represent the corrected pipe top and pipe bottom strains of the i-th trench compensation zone in the initial state. This refers to the outer diameter of the tube.

4. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The pressure holding continuous change component and the fallback recovery component Calculated using the following formula: ； ； in, and These represent the start time of the pressure holding test at the i-th trench compensation zone and the m-th test loading level, respectively. and the end of the pressure holding time The loading curvature increment, To maintain pressure for a certain period of time, and These represent the increments of loading curvature before and after the fallback, respectively, for the i-th trench compensation zone and the m-th test loading level. is the curvature regularization constant.

5. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The method combines the loading curvature increment, the pressure holding continuous change component, and the fallback recovery component to classify the trench support state into different support states, including: The trench support status is further classified based on at least one of the following: left and right side strain asymmetry, adjacent zone difference, reference synchronization degree, and pipe body jacking response. When the loading curvature increment, the pressure holding continuous change component, and the neighboring zone difference exceed the corresponding limit, and the fallback recovery component is lower than the corresponding limit, the classification is a loose or detached support state. When the asymmetry of the strain on the left and right sides or the lifting response of the tube exceeds the corresponding limit, or when the sign of the loading curvature increment is opposite to the expected bending direction and the difference between adjacent areas exceeds the corresponding limit, the condition is classified as a local hard point support state. When the reference synchronization degree shows that the bending response of the trench bottom reference survey line changes synchronously with that of multiple adjacent zones, the classification is an overall disturbance state; When all indicators are within the allowable limits, the condition is determined to be a continuous support state.

6. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The step of implementing a differentiated compensation scheme based on the different support states includes: For zones in a loose or voided support state, at least one compensation cell is selected according to the abnormal location and injected with low shrinkage compensation material. During the injection process, injection stop control is performed based on injection pressure, venting or backflow status, the loading curvature recovery rate, the tube lifting response, and the response transfer amount of the adjacent zone. For zones with localized hard point support, the injection of the low-shrinkage compensation material is prohibited, and instructions for excavation verification, hard point removal, or pad adjustment are output. For the partitioned overall disturbance state, the baseline survey line at the bottom of the trench, the test loading record, and the ambient temperature are reviewed first. The compensation grid injection is not executed directly, and an overall handling suggestion is output.

7. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The loading curvature recovery rate and the adjacent partition response transfer amount Determine by the following formula: ； ； in, and These represent the increments of loading curvature before and after compensation in the i-th trench compensation zone under the same experimental loading level. , , , These represent the loading curvature increments of the left and right adjacent zones before and after compensation for the i-th trench compensation zone. , is the curvature regularization constant.

8. The trench support state classification compensation method for long-distance pipelines before commissioning, as described in claim 1, is characterized in that... The verification of compensation effects and responses in adjacent zones, once deemed satisfactory, results in the output of construction files, including: Recalculate and verify the loading curvature recovery rate, the adjacent zone response transfer amount, the loading curvature increment, and the pipe lifting response. After the verification conditions are met, output the shaping and backfilling ready status, the pre-production verification status, and the construction archive.

9. A trench support condition classification compensation system for long-distance pipelines before commissioning, characterized in that, The system includes an input device, an output device, a processor, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to call the program instructions to execute the trench support state classification compensation method for long-distance pipelines before commissioning, as described in any one of claims 1-8.

Images