An underground pipeline displacement analysis correction system and method

Abstract

The application discloses a kind of underground pipeline displacement analysis correction system and method, it is related to pipeline displacement monitoring field, the application is based on Winkler foundation beam theory, after establishing pipeline displacement control equation, linear equation group with each pipe segment center point displacement as solving target can be obtained by using finite difference method to solve, the matrix in this equation group has obvious regularity, can be solved by means of MATLAB programming;Solving process is not dependent on the specific distribution form of soil displacement field, can be applied to any displacement field form;The vector superposition of comprehensive vertical settlement and horizontal displacement, more truly reflect pipeline space deformation state, improve existing pipeline safety evaluation reliability;In addition, through bed coefficient correlation soil stiffness characteristics, while considering vertical and horizontal pipe-soil interaction, solve the prediction deviation problem caused by traditional method ignoring pipe-soil separation effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of pipeline displacement monitoring, in particular, relates to a system and method for analyzing and correcting underground pipeline displacement. BACKGROUND

[0002] With the rapid advancement of urbanization in China, the ground space resources are increasingly saturated, and the development of underground space has become an inevitable choice for urban construction, and deep foundation pit engineering construction is showing a significant growth trend. Urban foundation pit engineering is often adjacent to the densely distributed existing underground pipeline network, and foundation pit excavation will inevitably cause soil disturbance, which will cause pipeline deformation, and when the deformation exceeds the safety threshold, it may cause pipeline rupture accidents, which seriously threatens the safety of urban lifeline projects;

[0003] The construction of foundation pit excavation will destroy the balance of the initial stress field of the soil, causing lateral deformation of the enclosure structure and the surrounding soil. This deformation process causes the adjacent underground pipeline to form a horizontal displacement towards the foundation pit; at the same time, the unloading effect of excavation will cause ground surface settlement outside the pit, and under the action of the pipeline will produce vertical displacement. When the cumulative amount of pipeline displacement reaches the allowable deformation threshold of the pipeline, it will cause the tensile fracture of the underground pipeline. SUMMARY

[0004] In view of the problems in the related art, the present application proposes an underground pipeline displacement analysis correction system and method to overcome the above technical problems existing in the prior art.

[0005] To solve the above technical problems, the present application is realized by the following technical solutions:

[0006] The present application is a kind of underground pipeline displacement analysis correction method, comprising the following steps:

[0007] S1, construct a pipe-soil vertical interaction model and a pipe-soil vertical interaction control equation; solve the pipe-soil vertical interaction control equation, and input the ground surface settlement data to calculate the underground pipeline vertical displacement data after solving;

[0008] S2, construct a pipe-soil horizontal interaction model and a pipe-soil horizontal interaction control equation; solve the pipe-soil horizontal interaction control equation, and input the soil horizontal displacement monitoring data to calculate the underground pipeline horizontal displacement data after solving;

[0009] S3, calculate the total displacement of the underground pipeline according to the underground pipeline vertical displacement data and the underground pipeline horizontal displacement data;

[0010] S4, repeat S1, S2 and S3 at multiple collection time points to calculate and collect the total displacement data of the underground pipeline to be monitored;

[0011] S5, comparing the underground pipeline displacement collected in S4 with the preset threshold value and predicting the displacement at the future time, then continuously comparing the prediction result with the preset threshold value, and according to the comparison results in two times, a pushing force is applied at the reverse position of the displacement direction to stabilize the pipeline displacement; after stabilization, a limiting slide is added and the pushing parameters are adjusted, and S1, S2 and S3 are repeated until the collected underground pipeline displacement and the displacement data at the corresponding future time are all less than the preset threshold value.

[0012] Preferably, S1 comprises the following steps:

[0013] S11, setting a bed coefficient, a spring support displacement boundary and a pipeline vertical displacement;

[0014] S12, constructing a pipe-soil vertical interaction model according to the bed coefficient, the spring support displacement boundary and the pipeline vertical displacement;

[0015] S13, establishing a second coordinate system according to the pipe-soil vertical interaction model; wherein the left end of the pipeline is taken as the coordinate origin of the axis; and then based on the second coordinate system, a second pipeline micro-section balance equation, a second beam deflection curve approximate differential equation and a second pipe-soil interaction force expression are constructed;

[0016] S14, obtaining a pipe-soil interaction control equation causing pipeline vertical deformation according to the second pipeline micro-section balance equation, the second beam deflection curve approximate differential equation and the second pipe-soil interaction force expression, which is recorded as a pipe-soil vertical interaction control equation;

[0017] S15, directly differentiating and approximating the differential term of the pipe-soil vertical interaction control equation to obtain a pipe-soil vertical interaction control algebraic equation;

[0018] S16, solving the pipe-soil vertical interaction control algebraic equation, and after solving, inputting the ground subsidence data to calculate the underground pipeline vertical displacement data.

[0019] Preferably, S2 comprises the following steps:

[0020] S21, obtaining a pipe-soil horizontal interaction model by drawing a foundation pit plan, merging the front and rear spring of the pipeline, correcting the bed coefficient corresponding to the pipe-soil interaction force in front of and behind the pipeline, and taking the soil horizontal displacement field as the elastic support displacement boundary and equivalent to the horizontal distributed load acting on the pipeline;

[0021] S22, establishing a first coordinate system according to the pipe-soil horizontal interaction model; wherein the left end of the pipeline is taken as the coordinate origin of the axis; ​A coordinate origin of the shaft; and constructing a first pipeline micro-section balance equation and a first pipeline-soil interaction force expression based on the first coordinate system;

[0022] S23, obtaining a pipeline-soil interaction control equation causing pipeline horizontal deformation from the first pipeline micro-section balance equation and the first pipeline-soil interaction force expression, denoted as a pipeline-soil horizontal interaction control equation;

[0023] S24, directly differentiating and approximating a differential term of the pipeline-soil horizontal interaction control equation to obtain a pipeline-soil horizontal interaction control algebraic equation;

[0024] S25, solving the pipeline-soil vertical interaction control algebraic equation, and inputting soil horizontal displacement monitoring data to calculate underground pipeline horizontal displacement data.

[0025] Preferably, the S3 comprises the following steps:

[0026] S31, calculating total displacement of the underground pipeline caused by the foundation pit excavation according to the underground pipeline vertical displacement data and the underground pipeline horizontal displacement data.

[0027] Preferably, the S4 comprises the following steps:

[0028] S41, setting a to-be-monitored underground pipeline and a plurality of time points at which the corresponding displacement data of the to-be-monitored underground pipeline is currently collected to obtain a current displacement collection time point set; in cooperation with the current displacement collection time point set, repeating the S1, S2 and S3 at each collection time point to calculate and collect total displacement data of the to-be-monitored underground pipeline to obtain a to-be-monitored displacement data set;

[0029] The periodic capture of displacement data is realized through the preset time point set, avoiding the intermittent defects of manual monitoring; the cyclic execution of the S1-S3 process is automatically triggered to ensure the synchronous update of data collection and model calculation, forming a closed loop chain of "monitoring-computing-storing", which is suitable for continuously changing engineering scenarios such as foundation pit excavation and can record the cumulative effect of pipeline displacement completely.

[0030] Preferably, the S5 comprises the following steps:

[0031] S51, setting a current underground pipeline displacement threshold;

[0032] S52, if there is displacement data greater than or equal to the current underground pipeline displacement threshold in the to-be-monitored displacement data set, executing a first measure set until there is no displacement data greater than or equal to the current underground pipeline displacement threshold in the to-be-monitored displacement data set;

[0033] Otherwise, the displacement data of the monitored underground pipeline at future time points is predicted according to the monitored displacement data set, to obtain a monitored future displacement data set; if there is displacement data greater than or equal to the current underground pipeline displacement threshold in the monitored future displacement data set, the second measure set is executed; otherwise, no measures need to be taken for the monitored underground pipeline;

[0034] The double-level verification mechanism of the current displacement data and the future prediction data constructs a three-dimensional protection system of "real-time alarm + trend prediction"; the current data exceeding the threshold value triggers an emergency response immediately, while the future prediction data exceeding the threshold value provides a buffer period, and preventive measures can be taken; both safety and overreaction are avoided, which is especially suitable for urban underground space sensitive to pipeline deformation.

[0035] Preferably, the first measure set in S52 includes the following steps:

[0036] S5211, according to the displacement direction corresponding to the displacement data in the monitored displacement data set, denoted as the current displacement direction; a plurality of displacement stable offset positions and displacement correction offset positions are set on the monitored underground pipeline, to obtain a displacement stable offset initial position set and a displacement correction offset initial position set;

[0037] S5212, a hydraulic jack is installed at each initial position in the displacement stable offset initial position set, and the thrust data of each hydraulic jack is set, to obtain a current hydraulic thrust initial data set; each hydraulic jack is started to work according to the current hydraulic thrust initial data set, and after working, the total displacement data of the monitored underground pipeline is calculated and collected in real time by repeating S1, S2 and S3, to obtain a current adjusted displacement data set;

[0038] If there is adjacent displacement data that is the same and subsequent adjacent displacement data that is the same in the current adjusted displacement data set, no adjustment is needed for the displacement stable offset initial position set and the current hydraulic thrust initial data set; otherwise, the displacement stable offset initial position set and the current hydraulic thrust initial data set are adjusted and S5212 is repeated until there is adjacent displacement data that is the same and subsequent adjacent displacement data that is the same in the current adjusted displacement data set;

[0039] S5213, displacement correction measures are performed in cooperation with the displacement correction offset initial position set until there is no displacement data greater than or equal to the current underground pipeline displacement threshold in the monitored displacement data set;

[0040] By establishing the two-stage displacement control of the displacement stable offset position set and the displacement correction offset position set and the homomorphism detection based on adjacent displacement data, the system stability state is automatically determined to avoid the hysteresis of manual intervention; when the displacement data does not reach the stable state, the system autonomously adjusts the offset position distribution and the thrust ratio to form a "monitoring-execution-verification" closed loop.

[0041] Preferably, the displacement correction measure performed in cooperation with the displacement correction offset initial position set in S5213 includes the following steps:

[0042] S52121, according to the displacement correction offset initial position set, a limiting slide is built under the underground pipeline to be monitored, and a hydraulic jack is installed again at each displacement correction offset initial position, and the thrust data of each hydraulic jack is set to obtain a current hydraulic correction initial data set; according to the current hydraulic correction initial data set, each hydraulic jack is started to work, and after working, S1, S2 and S3 are repeatedly performed in real time to calculate and collect the total displacement data of the underground pipeline to be monitored to obtain a current corrected displacement data set;

[0043] S52122, if the current corrected displacement data set has displacement data less than the current underground pipeline displacement threshold value and subsequent displacement data are all less than the current underground pipeline displacement threshold value, the current hydraulic correction initial data set and the displacement correction offset initial position set do not need to be adjusted; otherwise, the current hydraulic correction initial data set and the displacement correction offset initial position set are adjusted and S52122 is repeated until the current corrected displacement data set has displacement data less than the current underground pipeline displacement threshold value and subsequent displacement data are all less than the current underground pipeline displacement threshold value;

[0044] By the cooperative arrangement of the limiting slide and the multiple hydraulic jacks, a spatial force system network is formed, and combined with real-time displacement data collection, millimeter-level displacement compensation is realized; compared with traditional static support, the residual displacement amount can be greatly reduced; not only the single correction displacement meets the standard, but also the subsequent continuous data meet the requirements, effectively preventing the "false stability" phenomenon; when the correction fails, parameter adjustment is automatically triggered until the system converges within the safety threshold; in addition, the slide limiting device restricts the displacement development path in advance, converts potential sudden displacement into controllable gradual adjustment, and reduces the risk of pipeline burst.

[0045] Preferably, the second measure set in S52 includes the following steps:

[0046] S5221、In the displacement stable cancellation initial position set, each initial position is respectively installed with a hydraulic jack, and the thrust data of each hydraulic jack is set, so that a current hydraulic thrust initial data set is obtained;According to the current hydraulic thrust initial data set, each hydraulic jack is started to work, and after working, the total displacement data of the monitored underground pipeline is calculated and collected in real time by repeating S1, S2 and S3, so that an adjusted current displacement data set is obtained;

[0047] S5222、If there are adjacent displacement data that are the same and subsequent adjacent displacement data that are the same in the adjusted current displacement data set, the adjustment is completed;Otherwise, the displacement data of the monitored underground pipeline at future time points is predicted according to the adjusted current displacement data set, and a future adjusted displacement data set is obtained;If there is displacement data greater than or equal to the current underground pipeline displacement threshold in the future adjusted displacement data set, the displacement stable cancellation initial position set and the current hydraulic thrust initial data set are adjusted, and S5221 and S5222 are repeated until there is no displacement data greater than or equal to the current underground pipeline displacement threshold in the future adjusted displacement data set;

[0048] Through repeated monitoring, a "monitoring-calculation-adjustment" closed loop is formed, which ensures that the displacement prevention evolves synchronously with the soil deformation, and solves the problem of lagging of traditional static support;The "current displacement stability judgment-future displacement prediction-threshold secondary verification" three safeguards are set to avoid the risk of insufficient prevention caused by single adjustment;When the future predicted displacement is out of limit, the position set and the thrust set are automatically adjusted;In addition, through future displacement prediction, the pipeline deformation is controlled in the elastic stage, and sudden structure damage is avoided.

[0049] A kind of underground pipeline displacement analysis correction system, including pipe-soil vertical interaction control equation construction solving module, pipe-soil horizontal interaction control equation construction solving module, underground pipeline total displacement calculation module, monitored underground pipeline displacement data acquisition module and monitored underground pipeline displacement prevention correction module.

[0050] The present application has the following beneficial effects:

[0051] 1. In the present application, based on the Winkler foundation beam theory, the pipeline displacement control equation is established, and the finite difference method is used to solve the linear equation set with the displacement of each pipe segment center point as the solving target, and the matrix in the equation set has obvious regularity;The solving process does not depend on the specific distribution form of the soil displacement field, and can be applied to any displacement field form;The vector superposition of vertical settlement and horizontal displacement is more true to reflect the spatial deformation state of the pipeline, and improves the safety evaluation reliability of the existing pipeline.

[0052] 2. In the application, the pipeline is regarded as an elastic foundation beam buried in the ground, the improved foundation bed coefficient is used to consider the influence of the buried depth of the foundation soil, and the actual situation is more in line with the actual situation.

[0053] 3. In the application, by calculating the examples, the one-way displacement and bending moment of the pipeline and the total displacement and bending moment after the synthesis of the pipeline are compared, the maximum vertical displacement accounts for about 76.91% of the total displacement, and the maximum bending moment generated by the vertical bending accounts for about 75.21% of the total bending moment, therefore, according to the vertical bending deformation of the pipeline, it is more dangerous to judge whether the pipeline is damaged, and it is more reasonable to evaluate the safety condition of the pipeline according to the actual displacement and bending moment of the pipeline.

[0054] 4. In the application, the bed coefficient is used to associate the stiffness characteristics of the soil body, and the vertical and horizontal pipe-soil interaction is considered, so that the prediction deviation problem caused by the traditional method of ignoring the pipe-soil separation effect is solved; the finite difference method is used to discretize and solve the control equation, which significantly reduces the consumption of calculation resources compared with the traditional finite element method, and is especially suitable for long-distance pipeline analysis; through the separation type modeling (vertical spring support and horizontal bed reaction force), different pipeline stiffness, buried depth and soil conditions can be adapted, and quantitative basis is provided for foundation pit support design.

[0055] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0057] Figure 1 The bed coefficient of the application The schematic diagram of the calculation model;

[0058] Figure 2 The vertical displacement of the free soil body at the pipeline position of the application The schematic diagram of the calculation model;

[0059] Figure 3 The schematic diagram of the equivalent vertical distribution load of the soil settlement field of the application;

[0060] Figure 4 The stress analysis diagram of the vertical pipeline of the application;

[0061] Figure 5 The stress analysis diagram of the vertical micro-section of the application;

[0062] ​Figure 6 This is a schematic diagram of the vertical division of pipelines using the finite difference method of the present invention;

[0063] Figure 7 This is a schematic diagram of the calculation model for the interaction force between the pipe and the soil in front of and behind the pipeline of the present invention;

[0064] Figure 8 This is a schematic diagram of the calculation model for the correction of the bed bed coefficient in this invention;

[0065] Figure 9 This is a schematic diagram of the calculation model for the horizontal displacement field of soil in this invention;

[0066] Figure 10 This is a schematic diagram illustrating how the horizontal displacement field of soil is equivalent to a horizontally distributed load in this invention.

[0067] Figure 11 This is a force analysis diagram of the horizontal pipeline of the present invention;

[0068] Figure 12 The horizontal micro-segment of the present invention Force analysis diagram;

[0069] Figure 13 This is a schematic diagram of the horizontal pipeline division using the finite difference method of the present invention;

[0070] Figure 14 This is a flowchart of the calculation procedure for the governing equation of soil-pipe interaction in this invention;

[0071] Figure 15 This is a comparison diagram of the vertical displacement of the pipeline in this invention;

[0072] Figure 16 This is a comparison diagram of the total pipeline displacement of the present invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the invention.

[0074] Example 1

[0075] This embodiment is a method for correcting displacement of underground pipelines, including the following steps:

[0076] S1. Calculation of vertical displacement of underground pipelines;

[0077] The excavation of the foundation pit disrupts the original stress balance of the soil, which will inevitably cause the bottom of the pit to heave and the surface outside the pit to settle. Under this action, the underground pipeline will undergo vertical deformation. A vertical displacement calculation model can be established based on Winkler's elastic foundation beam theory for calculation.

[0078] S11, Pipe-Soil Interaction Model

[0079] Since this invention studies pipeline deformation caused by foundation pit excavation, the effects of pipeline self-weight, internal weights, and the self-weight of soil pressure above the pipeline are not considered.

[0080] Treating the pipeline as a Winkler foundation beam buried underground, the subgrade coefficient... The influence of the foundation soil depth can be considered; the method for determining the value is introduced below, and the calculation model is as follows: Figure 1 As shown; vertical displacement of the free soil at the pipeline location. As the spring support displacement boundary, it causes vertical displacement of the pipeline. Its calculation model is as follows Figure 2 As shown; the soil settlement field is equivalent to a vertically distributed load. When acting on the pipeline, an upward ground reaction force is generated due to the interaction between the pipe and the soil. Its calculation model is as follows Figure 3 As shown. Based on the above mechanical analysis, the distributed load acting on the pipeline can be expressed as:

[0081] (2.2)

[0082] S12. Derivation of governing equations:

[0083] Based on the previous derivation using Winkler's foundation beam theory, the stress model of the pipeline has been obtained. Now, the pipeline will be analyzed as a rod in mechanics of materials, and the governing equations for the interaction between the pipe and the soil in the vertical direction will be given using the basic relationships in mechanics of materials.

[0084] Based on the soil-pipe interaction model, establish as follows Figure 4 The coordinate system shown. The left end of the pipeline is taken as... The origin of the axis coordinate system is given, and the pipeline is located at... The load intensity at the location is The pipeline is The deflection at the point is .

[0085] Using coordinates and Two cross sections are cut with lengths of microsegments ,like Figure 5 As shown, let the coordinates be... The shear force and bending moment at the cross section are and The coordinates are The shear force and bending moment at the cross section are and The micro-segment is in equilibrium under the external force. Since is very small, the change of load intensity along can be neglected, and the equilibrium equation of the micro-segment of the pipeline is obtained as

[0086] From , represents the resultant force on the Figure 4 axis in :

[0087] (2.3)

[0088] Thus we have

[0089] (2.4)

[0090] From , represents the bending moment at the point in Figure 5 : C

[0091] (2.5)

[0092] Neglecting the second-order infinitesimal, we have

[0093] (2.6)

[0094] Combining (2.4) and (2.6), we have

[0095] (2.7)

[0096] According to the knowledge in material mechanics, in the case of pure bending, we have

[0097] (2.8)

[0098] In the formula, is the radius of curvature of the neutral layer, is the curvature of the neutral layer, is the moment of inertia of any cross section of the beam about the axis, is the elastic modulus of the pipeline, is the moment of inertia of the cross section of the pipeline about the neutral axis.

[0099] The above formula shows that, under the same bending moment, the deflection of the pipeline is proportional to ​The larger the value, the smaller the bending deformation of the pipeline, is called the bending stiffness of the pipeline.

[0100] Equation (2.8) represents the curvature expression of the pipeline under pure bending within the elastic range of the pipeline. When considering lateral force bending, although there are bending moments and shear forces acting on the cross section, due to the fact that the pipeline is generally long, according to the Euler-Bernoulli beam theory, when the span-to-diameter ratio is greater than 10, L the contribution of the shear force to the displacement field can be ignored. Therefore, equation (2.8) is still applicable, but in the equation and need to be represented as functions of the coordinate :

[0101] (2.9)

[0102] According to knowledge in higher mathematics, the curvature of a plane curve and the derivative of the curve equation have the following relationship:

[0103] (2.10)

[0104] In the current established coordinate system, when the beam is deformed, the sign of the bending moment is opposite to that of the bending moment . Therefore, substituting equation (2.10) into equation (2.9) gives:

[0105] (2.11)

[0106] Since the pipeline usually undergoes small deformation, the higher-order quantity can be ignored compared to 1, so the above equation can be approximated as:

[0107] (2.12)

[0108] Equation (2.12) is called the approximate differential equation of the deflection curve of the beam because it neglects the effect of the shear force and neglects the term in .

[0109] Through the above derivation, we can obtain:

[0110]

[0111] Combining the two equations gives:

[0112] (2.13)

[0113] (2.14)

[0114] wherein, is the diameter of the pipeline; is the soil resistance per unit area.

[0115] The previous pipe-soil interaction analysis model assumes that the vertical displacement of the free surface of the soil at the location of the pipeline is , the vertical displacement of the pipeline is , and the pipe-soil interaction force is obtained as:

[0116] (2.15)

[0117] Substituting equation (2.15) into equation (2.14) gives:

[0118] (2.16)

[0119] Equation (2.16) is the pipe-soil interaction control equation for the vertical deformation of the pipeline caused by the excavation of the foundation pit.

[0120] Reference values of the ground coefficient are given in the existing literature, as shown in Table 1.

[0121] Table 1 Reference values of the ground coefficient k0

[0122]

[0123] Method for calculating the ground base coefficient:

[0124] (2.17)

[0125] Equation (2.17) is based on an elastic foundation beam placed on the ground surface and does not consider the influence of the buried depth on the ground base coefficient. By improving the ground base coefficient of Vesic, the influence of the buried depth of the foundation soil can be considered. In the present application, the underground pipeline is regarded as a foundation beam buried underground, and therefore, the model formula of equation (2.18) and equation (2.19) is more in line with the actual situation of the present application, and the formula is as follows:

[0126] (2.18)

[0127] (2.19)

[0128] In the formula, is the buried depth of the pipeline; is the elastic modulus of the foundation soil; is the Poisson's ratio of the foundation soil.

[0129] S13, control equation solving

[0130] According to the foregoing analysis, the pipe-soil interaction control equation presents the characteristics of a fourth-order non-homogeneous differential equation. Such an equation can be discretized and solved using the finite difference method in numerical analysis. The finite difference method is an approximate method for solving numerical solutions of differential equations. The main principle is to directly difference approximate the differential terms in the differential equation, thereby converting the differential equation into an algebraic equation system for solving. In specific solving, the calculation region is first uniformly meshed, and the discrete nodes are numbered. The displacement at the node is expanded using Taylor series, and the differential term is replaced by the difference format through mathematical transformation, thereby finally realizing the conversion of the differential equation to the algebraic equation.

[0131] The pipeline in the calculation region is discretized and segmented along its axial direction, and the segments are equally divided with a length of . The nodes are numbered in the order from left to right, numbered as , and the vertical displacement of the midpoint of the th segment is defined as , as shown in Figure 6 .

[0132] According to the Taylor series expansion of the nodes and and the vertical displacements of the nodes and :

[0133] (2.20)

[0134] (2.21)

[0135] (2.22)

[0136] (2.23)

[0137] Adding equation (2.20) and equation (2.21) gives:

[0138] (2.24)

[0139] Adding equation (2.22) and equation (2.23) gives:

[0140] (2.25)

[0141] Solving equations (2.24) and (2.25) together and eliminating gives:

[0142] (2.26)

[0143] Neglecting the fourth order high order term, the fourth order central difference formula can be obtained:

[0144] (2.27)

[0145] The governing equation of pipe-soil interaction in vertical direction has been derived in the previous section. Equation (2.26) can be rearranged as:

[0146] (2.28)

[0147] Substituting equation (2.27) into equation (2.28) gives:

[0148] (2.29)

[0149] Here, we can obtain equations about unknowns Since there are unknowns in total, 4 more equations are needed to solve the problem. The missing equations are supplemented by boundary conditions.

[0150] According to the existing research results, when the two ends of the pipeline are fixed, the calculation results are in line with the law, so they are in line with the actual situation, so we have:

[0151] (2.30)

[0152] According to the differential relationship between the deflection, rotation angle, bending moment, and shear force of the beam in material mechanics, the rotation angle, bending moment, and shear force of the pipeline at any point along the axis can be expressed as:

[0153] (2.31)

[0154] (2.32)

[0155] (2.33)

[0156] Combining equations (2.20), (2.21), (2.30), and (2.31), we can obtain:

[0157] (2.34)

[0158] (2.35)

[0159] (2.36)

[0160] (2.37)

[0161] The four equations (2.34)~(2.37) based on the boundary condition supplement can make up the missing equations of the equation group (2.29), thereby constructing the vertical displacement of the center point of each pipe segment The linear equation group as the solution target is:

[0162] (2.38)

[0163] The above formula can be adjusted as:

[0164] (2.39)

[0165] Through the analysis of the matrix equation, it can be known that the equation group has independent equations, and unknown displacement quantities can be solved; the matrix and the matrix element distribution presents a specific regularity, which can be solved by MATLAB programming. Based on the obtained vertical displacement of the pipeline, the turning angle, bending moment and shear force of the pipeline can be respectively solved by combining equations (2.31)~(2.33); i =2,..., n -2) represents the vertical displacement of the free surface of the soil at the position of the divided i segment pipeline;

[0166] The obtained input surface subsidence data are used to calculate the vertical displacement data of the underground pipeline.

[0167] S2, horizontal displacement calculation of underground pipeline;

[0168] The original stress field of the disturbed soil in the foundation pit construction induces the lateral displacement of the enclosure structure and the soil together, and further causes the deformation of the adjacent underground pipeline in the direction of the foundation pit. The horizontal displacement calculation model can be established based on the Winkler elastic foundation beam theory for calculation, and the method is similar to the calculation method of the vertical displacement of the underground pipeline.

[0169] S21, pipe-soil interaction model;

[0170] Under the action of the foundation pit excavation, the enclosure structure and the soil outside the pit move in the direction of the pit. In order to facilitate the description of the positional relationship later, here the direction of the pipeline away from the foundation pit side is defined as forward, and the direction of the pipeline close to the foundation pit side is defined as backward. The soil in front of and behind the pipeline is equivalent to a spring, and it is assumed that the pipe-soil interaction forces in front of and behind the pipeline are and , respectively, the corresponding base coefficients are and , if the horizontal displacement of the pipeline is , then , , and the calculation model is as follows​Figure 7 As shown, to more clearly express the positional relationships in the calculation model, a plan view of the foundation pit is drawn within the model. The springs on both sides before and after the pipeline are combined, and the subgrade coefficient is corrected to... , computational model such Figure 8 As shown. The horizontal displacement field of the soil. As the displacement boundary of the elastic support, it causes horizontal displacement of the pipeline. Its calculation model is as follows Figure 9 As shown, the horizontal displacement field of the soil is equivalent to a horizontally distributed load. When acting on the pipeline, the ground reaction force generated by the interaction between the pipe and the soil... ,like Figure 10 As shown, based on the above mechanical analysis, the distributed load acting on the pipeline can be expressed as:

[0171] (2.40)

[0172] S22, Derivation of the governing equations

[0173] Similar to the reasoning process of the governing equations for soil-to-pipe interaction in the vertical direction, we first establish, as follows: Figure 11 The coordinate system shown. Assume the pipeline is in... The load intensity at the location is The pipeline is along The deflection in the axial direction is .

[0174] Using coordinates and Two cross sections are cut with lengths of microsegments ,like Figure 12 As shown, let the coordinates be... The shear force and bending moment at the cross section are respectively and Then the coordinates are The shear force and bending moment at the cross section are respectively and The micro-segment is in equilibrium under the action of external forces. Because... Small, load intensity can be neglected along From the changes in these parameters, we can obtain the equilibrium equations for the pipeline segments:

[0175] Depend on Know, express Figure 11 middle y Resultant force on the axis:

[0176] (2.41)

[0177] Thus, we have

[0178] (2.42)

[0179] From we have

[0180] (2.43)

[0181] Neglecting the second order infinitesimal, we have

[0182] (2.44)

[0183] From equations (2.42) and (2.44), we have

[0184] (2.45)

[0185] By analogy with the derivation of the vertical direction pipeline control equation, we have

[0186] (2.46)

[0187] From equations (2.45) and (2.46), we have

[0188] (2.47)

[0189] (2.48)

[0190] where is the pipeline diameter, is the soil resistance per unit area in the horizontal direction of the pipeline.

[0191] The previous soil-pipeline interaction analysis model assumes that the vertical displacement of the free surface of the soil at the pipeline location is and the vertical displacement of the pipeline is and the soil-pipeline interaction force is

[0192] (2.49)

[0193] From equations (2.48) and (2.49), we have

[0194] (2.50)

[0195] Equation (2.50) is the soil-pipeline interaction control equation for the horizontal deformation of the pipeline caused by foundation pit excavation.

[0196] According to existing research, the relationship between the horizontal and vertical bedding coefficients is as follows:

[0197] (2.51)

[0198] where, , denote the horizontal and vertical base bed coefficients, respectively;

[0199] S23, Control equation solution

[0200] The pipe-soil interaction control equation is a fourth-order non-homogeneous differential equation. Similar to the solution process of the vertical pipe-soil interaction control equation, the finite difference method is also used to solve it.

[0201] The pipeline in the load influence range is discretely segmented along its axial direction, and is equally divided into segments, each with a length defined as The nodes are sequentially numbered according to the extension direction of the pipeline, with the number being , and the horizontal displacement of the midpoint of the segment is defined as , as shown in Figure 13 .

[0202] According to the Taylor series expansion of the horizontal displacement of the nodes , , and , the fourth-order central difference formula can be obtained through conversion:

[0203] (2.52)

[0204] The pipe-soil interaction control equation in the horizontal direction has been obtained as described above, and equation (2.50) can be rearranged as:

[0205] (2.53)

[0206] Substituting equation (2.52) into equation (2.53) gives:

[0207] (2.54)

[0208] Here, we can obtain equations about the unknown . Since there are unknowns in the equation, 4 more equations are needed to solve it, and the missing equations are supplemented by the boundary conditions.

[0209] According to existing research results, when the two ends of the pipeline are fixed, the calculation results are in line with the rules, so they are in line with the actual situation, and therefore

[0210] (2.55)

[0211] According to the differential relationship between the deflection, rotation angle, bending moment and shear force of the beam in material mechanics, the rotation angle, bending moment and shear force of the pipeline at any point along the axial direction can be expressed as:

[0212] (2.56)

[0213] (2.57)

[0214] (2.58)

[0215] According to the formulas (2.20), (2.21), (2.55) and (2.56), it can be known that

[0216] (2.59)

[0217] (2.60)

[0218] (2.61)

[0219] (2.62)

[0220] The four equations (2.59)-(2.62) based on the boundary condition supplement can make up for the missing equations of the equation group (2.54), so that a linear equation group with the deflection of the center point of each pipe segment as the solving variable can be constructed:

[0221] (2.63)

[0222] The above formula can be arranged as:

[0223] (2.64)

[0224] Through the analysis of the matrix equation, it can be known that the equation group has independent equations, and unknown displacement quantities can be solved; the matrix and the matrix element distribution presents a specific regularity, which can be solved by MATLAB programming. Based on the obtained horizontal displacement of the pipeline, the rotation angle, bending moment and shear force of the pipeline can be respectively solved by combining the formulas (2.56)-(2.58); (2.65) i =2,..., n -2) represents the vertical displacement of the free surface of the soil at the position of the i segment of the divided pipeline;

[0225] The horizontal displacement data of the underground pipeline is calculated by inputting the solved soil horizontal displacement monitoring data.

[0226] S3, underground pipeline displacement calculation

[0227] From the foregoing derivation, in the case of known pipeline position, free soil vertical displacement and horizontal displacement, soil parameters, pipeline parameters, the horizontal and vertical pipe-soil interaction control equations can be established respectively, and then the pipeline is divided into equal parts, and the finite difference method can be used to obtain the pipeline node displacement matrix, and finally the MATLAB program is used to solve it. The flow chart of the program is shown in Figure 14 .

[0228] The foregoing use of the finite difference method respectively obtains the pipeline vertical displacement and horizontal displacement , and the superposition of the two vectors can obtain the total displacement of the underground pipeline caused by the foundation pit excavation .

[0229] (2.65)

[0230] S4, comparison and analysis of calculation results

[0231] S41, comparison of pipeline vertical displacement

[0232] Since only pipeline settlement monitoring points are provided in the present application, the pipeline vertical displacement obtained by the finite element calculation method and the two-stage analysis calculation method of the present application is compared with the monitoring data, as shown in Figure 15 , it can be seen from the figure that the pipeline vertical displacement calculated by the finite element method is larger, and the calculation result of the two-stage analysis method is closer to the monitoring value, which illustrates the rationality of the two-stage analysis method proposed in the present application.

[0233] S42, comparison of pipeline total displacement

[0234] Only considering the pipeline vertical displacement is dangerous, therefore, the total displacement of the pipeline calculated by the finite element calculation method, the two-stage analysis method and the pipeline deformation empirical formula is compared, as shown in Figure 16 . It can be seen from the figure that the total displacement of the pipeline calculated by the finite element method is the largest, the calculation result of the two-stage analysis method is the smallest, and the calculation result of the pipeline deformation empirical formula is between the two;

[0235] S5, the displacement data collection module of the monitored underground pipeline repeats S1, S2 and S3 at each collection time point, and the total displacement data of the monitored underground pipeline is calculated and collected.

[0236] The S5 includes the following steps:

[0237] S51, set the underground pipeline to be monitored and a plurality of time points at which the displacement data corresponding to the underground pipeline to be monitored is currently collected, to obtain a current displacement collection time point set; in cooperation with the current displacement collection time point set, S1, S2 and S3 are repeated at each collection time point to collect and calculate the total displacement data of the underground pipeline to be monitored, to obtain a monitored displacement data set;

[0238] The periodic capture of displacement data is realized through the preset time point set, avoiding the intermittent defects of manual monitoring; the cyclic execution of the S1-S3 process is automatically triggered, ensuring the synchronous update of data collection and model calculation, forming a closed loop chain of "monitoring-computing-storage", which is suitable for continuously changing engineering scenarios such as foundation pit excavation, and can record the cumulative effect of pipeline displacement completely;

[0239] S6, the underground pipeline displacement correction module compares the underground pipeline displacement collected in S5 with a preset threshold value and predicts the displacement at a future time, and then compares the prediction result with the preset threshold value again, and according to the results of the two comparisons, a pushing force is applied at the reverse position of the displacement direction to stabilize the pipeline displacement; after stabilization, a limiting slide is added and the pushing parameters are adjusted, and S1, S2 and S3 are repeated until the collected underground pipeline displacement and the displacement data at the corresponding future time do not exceed the preset threshold value;

[0240] The S6 includes the following steps:

[0241] S61, set a current underground pipeline displacement threshold value;

[0242] Specifically, the setting of the current underground pipeline displacement threshold value can refer to the following:

[0243] Rigid pipe material (concrete / cast iron): vertical displacement threshold value ≤0.2% pipeline span, horizontal displacement threshold value ≤15mm; flexible pipe material (PE / PVC): allowable relative deformation rate ≤5% pipe diameter; special medium pipeline (gas / hazardous chemicals) needs to additionally perform the mandatory requirement of displacement ≤10mm in the "Pressure Pipe Safety Technology Supervision Regulations";

[0244] S62, if there is displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored displacement data set, execute the first measure set until there is no displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored displacement data set;

[0245] Otherwise, according to the monitored displacement data set, the displacement data of the underground pipeline to be monitored at a plurality of future time points is predicted to obtain a monitored future displacement data set; if there is displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored future displacement data set, the second measure set is executed; otherwise, no measures need to be taken for the underground pipeline to be monitored;

[0246] The first measures in S62 include the following steps:

[0247] S6211, record the displacement direction corresponding to the displacement data in the to-be-monitored displacement data set as the current displacement direction; set a plurality of displacement stable offset positions and displacement correction offset positions on the to-be-monitored underground pipeline to obtain a displacement stable offset initial position set and a displacement correction offset initial position set;

[0248] Specifically, the displacement stable offset initial position set and the displacement correction offset initial position set can be freely laid according to the pipeline orientation, and are compatible with straight sections, elbows, tees and other complex pipeline sections.

[0249] S6212, install hydraulic jacks at each initial position in the displacement stable offset initial position set and set the thrust data of each hydraulic jack to obtain a current hydraulic thrust initial data set; start each hydraulic jack to work according to the current hydraulic thrust initial data set, and after working, real-time repeat S1, S2 and S3 to calculate and collect the total displacement data of the to-be-monitored underground pipeline to obtain a current adjusted displacement data set;

[0250] If there are adjacent displacement data that are the same and subsequent adjacent displacement data that are all the same in the current adjusted displacement data set, the displacement stable offset initial position set and the current hydraulic thrust initial data set do not need to be adjusted; otherwise, the displacement stable offset initial position set and the current hydraulic thrust initial data set are adjusted and S6212 is repeated until there are adjacent displacement data that are the same and subsequent adjacent displacement data that are all the same in the current adjusted displacement data set.

[0251] S6213, perform displacement correction measures in cooperation with the displacement correction offset initial position set until there is no displacement data greater than or equal to the current underground pipeline displacement threshold in the to-be-monitored displacement data set.

[0252] S6213 includes the following steps of performing displacement correction measures in cooperation with the displacement correction offset initial position set:

[0253] S62121, according to the displacement correction offset initial position set, build a limiting slide under the to-be-monitored underground pipeline and install hydraulic jacks again at each displacement correction offset initial position and set the thrust data of each hydraulic jack to obtain a current hydraulic correction initial data set; start each hydraulic jack to work according to the current hydraulic correction initial data set, and after working, real-time repeat S1, S2 and S3 to calculate and collect the total displacement data of the to-be-monitored underground pipeline to obtain a current corrected displacement data set;

[0254] S62122, if the current modified displacement data set has displacement data less than the current underground pipeline displacement threshold and subsequent displacement data are all less than the current underground pipeline displacement threshold, the current hydraulic correction initial data set and the displacement correction counter initial position set do not need to be adjusted; otherwise, the current hydraulic correction initial data set and the displacement correction counter initial position set are adjusted and S62122 is repeated until the current modified displacement data set has displacement data less than the current underground pipeline displacement threshold and subsequent displacement data are all less than the current underground pipeline displacement threshold;

[0255] By the cooperative arrangement of the limiting slide and the multiple hydraulic jacks, a spatial force system network is formed, and combined with real-time displacement data acquisition, millimeter-level displacement compensation is realized; compared with traditional static support, the residual displacement amount can be reduced by 60%-80%; the thrust data of each jack is dynamically adjusted according to the "hydraulic correction initial data set", and automatically responds to the non-uniformity of soil parameters; for example, the jack in the soft soil area automatically increases the output by 20%-30%, avoiding secondary deformation caused by local stress concentration; not only the displacement after single correction meets the standard, but also the subsequent continuous data meet the requirements, effectively preventing the "false stability" phenomenon; when the correction fails, parameter adjustment (S52122 cycle) is automatically triggered until the system converges within the safety threshold; in addition, the displacement development path is constrained in advance by the slide limiting device, converting potential sudden displacement into controllable gradual adjustment, reducing the pipeline burst risk by more than 90%; and precise correction avoids the waste of steel caused by traditional "excessive support", which can save support material cost by 35%-50%;

[0256] By establishing a two-stage displacement control of the displacement stable counter position set and the displacement correction counter position set, specifically, the hydraulic jack array forms a continuous resistance field at the stable counter position, and through self-adaptive adjustment of the thrust, the stress release effect of the soil is counteracted; the active jacking mechanism at the correction counter position can reconfigure the spatial shape of the pipeline, and its effect is verified by real-time displacement data feedback; based on the homomorphism detection of adjacent displacement data, the system stability state is automatically judged to avoid the lag of artificial intervention; when the displacement data does not reach the steady state, the system adjusts the counter position distribution and thrust ratio independently, forming a "monitoring-execution-verification" closed loop; in addition, the hydraulic thrust system quickly suppresses the displacement development trend to prevent sudden damage;

[0257] The double-level checking mechanism of current displacement data and future prediction data constructs a three-dimensional protection system of "real-time alarm + trend prediction". When the current data exceeds the threshold, emergency response is triggered immediately, while the future prediction data exceeding the threshold provides a buffer period for preventive measures. This method ensures safety and avoids overreaction, especially suitable for urban underground space sensitive to pipeline deformation. Based on the time series prediction of historical data set, the pipeline displacement development curve can be generated to provide quantitative basis for engineers to adjust excavation parameters and reinforcement scheme, realizing the transition from passive emergency to active prevention and control. In addition, through the threshold triggering mechanism, only in the case of data anomaly, the emergency plan is started, and in normal state, only the basic monitoring frequency is maintained, effectively avoiding the resource consumption of all-weather full-quantity monitoring, significantly reducing the occupation of computing resources and manual review costs.

[0258] The second set of measures in S62 includes the following steps:

[0259] S6221, install hydraulic jacks at each initial position in the set of initial positions for displacement stable compensation and set the thrust data of each hydraulic jack to obtain a set of initial hydraulic thrust data; start each hydraulic jack according to the set of initial hydraulic thrust data, and after working, real-time repeat S1, S2 and S3 to calculate and collect the total displacement data of the underground pipeline to be monitored to obtain a set of adjusted current displacement data.

[0260] S6222, if there are adjacent displacement data in the set of adjusted current displacement data that are the same and subsequent adjacent displacement data are the same, the adjustment is complete; otherwise, predict the displacement data of the underground pipeline to be monitored at multiple future time points according to the set of adjusted current displacement data to obtain a set of future adjusted displacement data; if there is displacement data greater than or equal to the current underground pipeline displacement threshold in the set of future adjusted displacement data, adjust the set of initial positions for displacement stable compensation and the set of initial hydraulic thrust data and repeat S6221 and S6222 until there is no displacement data greater than or equal to the current underground pipeline displacement threshold in the set of future adjusted displacement data.

[0261] For example, taking a subway foundation excavation project as an example, as follows:

[0262] Adjacent to a DN800 cast iron water supply pipeline with a buried depth of 2.5 m; the monitoring data is as follows:

[0263] Initial displacement threshold: vertical 10 mm / horizontal 8 mm; out-of-limit point: vertical displacement of 12.6 mm at pile number K3+120 (26% over limit);

[0264] The first set of measures is implemented (current displacement overrun): 1. Displacement stable offset stage, step implementation: displacement stable offset position set: K3+115, K3+125 (interval 5 m); hydraulic jack parameters: type: QL50; initial thrust: K3+115→80 kN, K3+125→75 kN; stroke accuracy: ±0.5 mm;

[0265] Dynamic adjustment process: the data after the first and second pressurization are shown in Tables 2 and 3, respectively:

[0266] Table 2

[0267]

[0268] Judgment: displacement is not stable→ adjust the thrust to K3+115→85 kN, K3+125→80 kN, and perform the second pressurization;

[0269] Table 3

[0270]

[0271] Displacement correction stage: limit slide rail construction: material: H-shaped steel rail (200×200×8 mm); installation inclination: 3° in the displacement direction (auxiliary backstop);

[0272] Corrected jacking parameters: jacking speed: 0.5 mm / min; staged loading: 50%→75%→100% design thrust (maximum 120 kN);

[0273] Effect verification: as shown in Table 4 below:

[0274] Table 4

[0275]

[0276] Second set of measures (predicted displacement overrun):

[0277] Predicted data: future 72h displacement curve: t=24h→9.8mm, t=48h→10.5mm (overrun), t=72h→11.2mm;

[0278] Pre-treatment measures: pre-jacking device: installation points: K3+110~K3+130 (interval 2 m); pre-load: 70 kN (80% of the design value);

[0279] Effect verification: as shown in Table 5 below:

[0280] Table 5

[0281]

[0282] Through repeated monitoring, a "monitoring-computing-adjustment" closed loop is formed to ensure that displacement prevention evolves synchronously with soil deformation, solving the problem of lagging of traditional static support; a triple guarantee of "current displacement stability determination-future displacement prediction-threshold secondary verification" is set to avoid the risk of insufficient prevention caused by single adjustment; differentiated force of jacks at different positions (such as increasing the pushing force by 20%~30% in the bending section) is dynamically adjusted according to the displacement rate; when the future predicted displacement exceeds the limit, automatic triggering of position set and pushing force set dual adjustment is formed to form a double fault-tolerant mechanism of "mechanical compensation + algorithm correction"; in addition, through future displacement prediction, pipeline deformation is controlled in the elastic stage (strain ≤0.1%), avoiding sudden structural damage.

[0283] Embodiment Two

[0284] The embodiment discloses a kind of underground pipeline displacement analysis correction systems, the system can realize the method of above-mentioned embodiment, including pipe-soil vertical interaction control equation construction solving module, pipe-soil horizontal interaction control equation construction solving module, underground pipeline total displacement calculation module, monitored underground pipeline displacement data acquisition module and monitored underground pipeline displacement prevention correction module;

[0285] The pipe-soil vertical interaction control equation construction solving module constructs pipe-soil vertical interaction model and pipe-soil vertical interaction control equation;Pipe-soil vertical interaction control equation is solved, and after solving, input ground subsidence data to calculate underground pipeline vertical displacement data;

[0286] The pipe-soil horizontal interaction control equation construction solving module constructs pipe-soil horizontal interaction model and pipe-soil horizontal interaction control equation;Pipe-soil horizontal interaction control equation is solved, and after solving, input soil horizontal displacement monitoring data to calculate underground pipeline horizontal displacement data;

[0287] The underground pipeline total displacement calculation module calculates underground pipeline total displacement according to underground pipeline vertical displacement data and underground pipeline horizontal displacement data;

[0288] The monitored underground pipeline displacement data acquisition module repeatedly S1, S2 and S3 at each acquisition time point, to calculate and collect the total displacement data of monitored underground pipeline;

[0289] The underground pipeline displacement to be monitored prevents correction module compares the underground pipeline displacement collected by S4 with the preset threshold value and predicts the displacement at future time, and then compares the prediction result with the preset threshold value again, and according to the comparison results, a pushing force is applied at the reverse position of the displacement direction to stabilize the pipeline displacement; after stabilization, a limiting slide is added and the pushing parameters are adjusted, and S1, S2 and S3 are repeated until the collected underground pipeline displacement and the displacement data at the corresponding future time are all less than the preset threshold value.

[0290] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the invention. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0291] The above disclosed preferred embodiments of the invention are only used to help explain the invention. The preferred embodiments do not describe all the details and limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of the present specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the invention, so that those skilled in the art can well understand and utilize the invention.

Claims

1. A method of correcting an analysis of displacement of an underground pipeline, characterized by, The method comprises the following steps: S1, constructing a pipe-soil vertical interaction model and a pipe-soil vertical interaction control equation; solving the pipe-soil vertical interaction control equation, and inputting ground settlement data to calculate underground pipeline vertical displacement data after solving; S2, constructing a pipe-soil horizontal interaction model and a pipe-soil horizontal interaction control equation; solving the pipe-soil horizontal interaction control equation, and inputting soil horizontal displacement monitoring data to calculate underground pipeline horizontal displacement data after solving; S3, calculating underground pipeline total displacement according to underground pipeline vertical displacement data and underground pipeline horizontal displacement data; S4, repeating S1, S2 and S3 to calculate and collect total displacement data of the underground pipeline to be monitored at multiple collection time points; S5, comparing the underground pipeline displacement collected in S4 with a preset threshold value, predicting the displacement at a future time, comparing the prediction result with the preset threshold value again, and applying a thrust force in the reverse position of the displacement direction according to the two comparison results to stabilize the pipeline displacement; after stabilization, a limiting slide is added and the thrust parameter is adjusted, and S1, S2 and S3 are repeated until the collected underground pipeline displacement and the displacement data at the corresponding future time do not exceed the preset threshold value.

2. The method of claim 1, wherein, The S1 comprises the following steps: S11, setting a bed coefficient, a spring support displacement boundary and a pipeline vertical displacement; S12, constructing a pipe-soil vertical interaction model according to the bed coefficient, the spring support displacement boundary and the pipeline vertical displacement; S13, establishing a second coordinate system according to the pipe-soil vertical interaction model; wherein the left end of the pipeline is taken as the coordinate origin of the shaft; and then constructing a second pipeline micro-section balance equation, a second beam deflection curve approximate differential equation and a second pipe-soil interaction force expression based on the second coordinate system. the coordinate origin of the shaft; and then constructing a second pipeline micro-section balance equation, a second beam deflection curve approximate differential equation and a second pipe-soil interaction force expression based on the second coordinate system. S14, obtaining a pipe-soil interaction control equation causing pipeline vertical deformation according to the second pipeline micro-section balance equation, the approximate differential equation of the deflection curve of the second beam and the second pipe-soil interaction force expression, and recording the pipe-soil vertical interaction control equation as a pipe-soil vertical interaction control equation; S15, directly differentiating and approximating the differential term of the pipe-soil vertical interaction control equation to obtain a pipe-soil vertical interaction control algebraic equation; S16, solving the pipe-soil vertical interaction control algebraic equation, and inputting ground settlement data to calculate underground pipeline vertical displacement data after solving.

3. The method of claim 1, wherein, The S2 comprises the following steps: S21, obtaining a pipe-soil horizontal interaction model by drawing a foundation pit plan, merging the front and rear springs of the pipeline, correcting the bed coefficients corresponding to the pipe-soil interaction forces in front of and behind the pipeline, and taking the soil horizontal displacement field as an elastic support displacement boundary and equivalent to a horizontal distributed load acting on the pipeline; S22, establishing a first coordinate system according to the pipe-soil horizontal interaction model; wherein the left end of the pipeline is taken as the coordinate origin of the axis; and then constructing a first pipeline micro-section balance equation and a first pipe-soil interaction force expression based on the first coordinate system; the coordinate origin of the axis; and then constructing a first pipeline micro-section balance equation and a first pipe-soil interaction force expression based on the first coordinate system; S23, obtaining a pipe-soil horizontal interaction control equation causing pipeline horizontal deformation according to the first pipeline micro-section balance equation and the first pipe-soil interaction force expression, and recording the pipe-soil horizontal interaction control equation as a pipe-soil horizontal interaction control equation; S24, directly differentiating and approximating the differential term of the pipe-soil horizontal interaction control equation to obtain a pipe-soil horizontal interaction control algebraic equation; S25, solving the pipe-soil vertical interaction control algebraic equation, and inputting soil horizontal displacement monitoring data to calculate underground pipeline horizontal displacement data after solving.

4. The method of claim 3, wherein, The S3 comprises the following steps: S31, calculating total displacement of the underground pipeline caused by the foundation pit excavation according to the vertical displacement data of the underground pipeline and the horizontal displacement data of the underground pipeline.

5. The method of claim 1, wherein, The S4 comprises the following steps: S41, setting the underground pipeline to be monitored and a plurality of time points at which the displacement data corresponding to the underground pipeline to be monitored is currently collected, to obtain a current displacement collection time point set; cooperating with the current displacement collection time point set, repeating S1, S2 and S3 at each collection time point to calculate and collect the total displacement data of the underground pipeline to be monitored, and obtaining a monitored displacement data set.

6. The method of claim 5, wherein: The S5 comprises the following steps: S51, setting a current underground pipeline displacement threshold value; S52, if there is displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored displacement data set, executing a first measure set until there is no displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored displacement data set; Otherwise, predicting the displacement data of the underground pipeline to be monitored at a plurality of future time points according to the monitored displacement data set to obtain a monitored future displacement data set; if there is displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored future displacement data set, executing a second measure set; otherwise, no measures need to be taken for the underground pipeline to be monitored.

7. The method of claim 6, wherein, The first measure set in S52 comprises the following steps: S5211, recording the displacement direction corresponding to the displacement data in the monitored displacement data set as a current displacement direction; setting a plurality of displacement stable offset positions and displacement correction offset positions on the underground pipeline to be monitored to obtain a displacement stable offset initial position set and a displacement correction offset initial position set; S5212, installing a hydraulic jack at each initial position in the displacement stable offset initial position set and setting the thrust data of each hydraulic jack to obtain a current hydraulic thrust initial data set; starting each hydraulic jack to work according to the current hydraulic thrust initial data set, and after working, repeatedly collecting the total displacement data of the underground pipeline to be monitored in real time by S1, S2 and S3 to obtain a current adjusted displacement data set; If there are adjacent displacement data that are the same and subsequent adjacent displacement data that are all the same in the current adjusted displacement data set, the displacement stable offset initial position set and the current hydraulic thrust initial data set do not need to be adjusted; otherwise, the displacement stable offset initial position set and the current hydraulic thrust initial data set are adjusted and S5212 is repeated until there are adjacent displacement data that are the same and subsequent adjacent displacement data that are all the same in the current adjusted displacement data set; S5213, cooperating with the displacement correction offset initial position set to execute displacement correction measures until there is no displacement data greater than or equal to the current underground pipeline displacement threshold value in the monitored displacement data set.

8. The method of claim 7, wherein, The displacement correction measures cooperating with the displacement correction offset initial position set in S5213 comprise the following steps: S52121, according to the displacement correction offset initial position set, a limit slide is built under the underground pipeline to be monitored, and a hydraulic jack is installed again at each displacement correction offset initial position, and the thrust data of each hydraulic jack is set to obtain a current hydraulic correction initial data set; each hydraulic jack is started to work according to the current hydraulic correction initial data set, and after working, the total displacement data of the underground pipeline to be monitored is calculated and collected in real time by repeating S1, S2 and S3 to obtain a current corrected displacement data set; S52122, if the current corrected displacement data set has displacement data less than the current underground pipeline displacement threshold and subsequent displacement data are all less than the current underground pipeline displacement threshold, the current hydraulic correction initial data set and the displacement correction offset initial position set do not need to be adjusted; otherwise, the current hydraulic correction initial data set and the displacement correction offset initial position set are adjusted and S52122 is repeated until the current corrected displacement data set has displacement data less than the current underground pipeline displacement threshold and subsequent displacement data are all less than the current underground pipeline displacement threshold.

9. The method of claim 8, wherein, The second measure set in S52 includes the following steps: S5221, a hydraulic jack is installed at each initial position in the displacement stable offset initial position set, and the thrust data of each hydraulic jack is set to obtain a current hydraulic thrust initial data set; each hydraulic jack is started to work according to the current hydraulic thrust initial data set, and after working, the total displacement data of the underground pipeline to be monitored is calculated and collected in real time by repeating S1, S2 and S3 to obtain an adjusted current displacement data set; S5222, if the adjusted current displacement data set has adjacent displacement data that are the same and subsequent adjacent displacement data that are all the same, the adjustment is completed; otherwise, the displacement data of the underground pipeline to be monitored at future time points is predicted according to the adjusted current displacement data set to obtain a future adjusted displacement data set; if the future adjusted displacement data set has displacement data greater than or equal to the current underground pipeline displacement threshold, the displacement stable offset initial position set and the current hydraulic thrust initial data set are adjusted and S5221 and S5222 are repeated until there is no displacement data greater than or equal to the current underground pipeline displacement threshold in the future adjusted displacement data set.

10. A system for implementing the underground pipeline displacement analysis correction method according to any one of claims 1-9.

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