Method for judging next-time mining damage of high-pressure gas pipeline due to influence of coal mining

Abstract

The invention discloses a method for judging the influence of coal mining on next-time mining damage of a high-pressure gas pipeline, and relates to the technical field of pipeline safety. Comprising the following steps: acquiring basic general situation data and actual measurement data of a research area in which a to-be-measured sub-high-pressure gas pipeline is laid; determining a predicted direction according to the direction relationship between the measured data of the research area and the general situation of the research area; the predicted direction is compared with the mining direction of the working face general situation, and the coal seam mining direction of the research area is determined; performing multi-angle subsidence prediction on the earth surface around the sub-high-pressure gas pipeline to be measured through the prediction model to obtain an earth surface movement deformation value; fourier fitting is carried out on the surface movement deformation value, boundary conditions of the research area are input into a fitting function, and a failure criterion of the to-be-tested sub-high pressure gas pipeline is obtained; and determining the mining damage of the to-be-detected secondary high-pressure gas pipeline according to the failure criterion. Whether the secondary high-pressure gas pipeline is in the safe state or not can be quickly judged, and the safety and stability of the coal mining process are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline safety, and in particular to a method for determining the impact of coal mining on the mining damage of a high-pressure gas pipeline. Background Art

[0002] With the development of the coal industry, the contradiction between coal resource development and the protection of buried pipeline safety has become increasingly prominent, and the protection of pipeline safety is of vital importance. The root cause of the impact of mining on buried pipelines is the deformation of the surface soil caused by underground mining. Coal mining will cause the surface soil to deform, which in turn affects the buried pipelines and causes them to deform or be damaged. This phenomenon is actually the result of the interaction between the buried pipeline and the surrounding soil. Research on the interaction between buried pipelines and soil layers mainly focuses on engineering fields such as earthquakes, landslides, fault activities, excavation of soil layers near pipelines (foundation pits and tunnel excavations), and urban foundation settlement, while research on the mechanical deformation of pipelines in goaf areas is relatively rare.

[0003] In the prior art, numerical simulation methods are used as the main research tools, and computer software and mathematical models are used to simulate the interaction between buried pipelines and soil. The stress-strain state of buried pipelines under different mining conditions and different burial conditions is deeply analyzed. Combined with various working conditions, the stress-strain state of pipelines under the influence of mining at corresponding positions of different deformations, combined with the allowable stress-strain value of the pipeline, it is judged whether the pipeline is in a safe state, and pipeline prevention and control technologies and measures are proposed.

[0004] The defects of the above-mentioned existing technology are: the allowable stress value and the allowable surface deformation value given by the safety evaluation method are fixed values, but the pipeline can withstand values ​​in different mining areas, different materials, different burial conditions, depths, soil properties, etc. are different. The existing numerical simulation method does not take into account the difference in the pipeline's tolerable values ​​during the simulation process, resulting in the predicted pipeline deformation position being inaccurate, and unable to ensure the safety and stability of the coal seam mining process. Summary of the invention

[0005] Based on this, it is necessary to provide a method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage in response to the above technical issues.

[0006] The embodiment of the present invention provides a method for determining whether coal mining affects the next mining damage of a high-pressure gas pipeline, including:

[0007] Obtain basic profile data and measured data of the study area where the sub-high pressure gas pipeline to be tested is laid; the basic profile data includes the study area profile, working face profile and boundary conditions;

[0008] According to the directional relationship between the overview of the study area and the measured data, the expected direction of the numerical simulation of the sub-high pressure gas pipeline to be tested is determined; the expected direction is compared with the mining direction reflected by the overview of the working face to determine the mining direction of the coal seam in the study area;

[0009] Construct a prediction model, which is used to characterize the influence of mining damage on the surface around the sub-high pressure gas pipeline to be tested in the direction of coal seam mining; use the prediction model to predict the subsidence of the surface around the sub-high pressure gas pipeline to be tested at multiple angles, and obtain the surface movement deformation value of the sub-high pressure gas pipeline to be tested along the direction of coal seam mining;

[0010] Perform Fourier fitting on the ground surface movement deformation value to obtain a fitting function, which is used to determine the stress condition of the sub-high pressure gas pipeline after it is damaged by mining;

[0011] The boundary conditions of the study area are input into the fitting function to obtain the failure criterion of the sub-high pressure gas pipeline to be tested, and the mining damage of the sub-high pressure gas pipeline to be tested is determined according to the failure criterion.

[0012] Optionally, the prediction model includes a geometric model and a constitutive model;

[0013] The geometric model includes a pipeline geometric model representing the size of the sub-high pressure gas pipeline and a soil geometric model representing the terrain around the pipeline;

[0014] The constitutive model includes pipeline constitutive model and soil constitutive model;

[0015] The pipeline constitutive model is a linear elastic model, which is used to reflect the strain of the sub-high pressure gas pipeline to be tested in the elastic stage, yield stage, strengthening stage and necking stage of the pipeline strain and stress relationship curve;

[0016] The soil constitutive model includes: for the elastic part of the soil, the linear elastic model is used as the soil constitutive model; for the plastic part of the soil, the Mohr-Coulomb model is used as the soil plastic model and also as the soil constitutive model.

[0017] Alternatively, the Mohr-Coulomb model is a mathematical model used to describe the response of brittle materials under shear stress and normal stress, and its expression is:

[0018] Draw Mohr circles representing the failure state on the maximum principal stress plane and the minimum principal stress plane. The expression of the contact line between the two Mohr circles is:

[0019]

[0020] Among them, τ max is the maximum shear stress, σ mis the average principal stress, c is the cohesion of the material, is the internal friction angle of the material.

[0021] Optionally, the influence of mining damage on the ground surface around the sub-high pressure gas pipeline in the coal seam mining direction, wherein the influencing factors are divided into pipeline laying factors and underground factors;

[0022] Pipeline laying factors include: pipeline materials and working surface conditions;

[0023] Pipeline materials include: strength, stiffness, toughness and diameter-to-thickness ratio;

[0024] Working surface conditions include working surface dimensions;

[0025] Downhole factors include: site conditions, mining conditions and burial methods;

[0026] Site conditions include soil mechanical parameters and backfill properties;

[0027] Mining conditions include dip, direction and velocity;

[0028] The burial method includes the laying method and the burial depth.

[0029] Optionally, the predicted model is used to predict the subsidence of the ground around the sub-high pressure gas pipeline to be tested at multiple angles, specifically including the prediction of subsidence of the sub-high pressure gas pipeline to be tested at 0°, 15°, 45°, 60°, 75° and 90° to the coal seam mining direction.

[0030] Optionally, Fourier fitting is performed on the ground surface movement deformation value, which specifically includes:

[0031] The east-west, north-south and vertical displacement distribution curves of the sub-high-pressure gas pipeline to be tested are obtained by fitting the surface deformation values ​​of the east-west, north-south and vertical directions of the sub-high-pressure gas pipeline to be tested during mining through the expansion formula of the Fourier eight-parameter series.

[0032] The expansion formula of the Fourier eight-parameter series is:

[0033]

[0034] Among them, a0, a n and b n is the Fourier coefficient, x is the position of the point, and N is the order of expansion;

[0035] The east-west displacement distribution curve, the north-south displacement distribution curve and the vertical displacement distribution curve are used as boundary conditions, and the stress, strain distribution and force conditions of the sub-high pressure gas pipeline to be tested are calculated according to the boundary conditions.

[0036] Optionally, the east-west displacement distribution curve and the north-south displacement distribution curve of the sub-high pressure gas pipeline to be tested are used to reflect the horizontal movement of the ground surface around the sub-high pressure gas pipeline to be tested;

[0037] The vertical displacement distribution curve of the sub-high pressure gas pipeline to be tested is used to characterize the vertical subsidence or uplift of the ground surface around the sub-high pressure gas pipeline to be tested.

[0038] Optionally, the failure criteria of the sub-high pressure gas pipeline to be tested include surface displacement distribution, stress distribution and pipeline deformation.

[0039] The above-mentioned method for determining the damage of the next high-pressure gas pipeline caused by coal mining provided by the embodiment of the present invention has the following beneficial effects compared with the prior art:

[0040] The present invention obtains basic profile data and measured data of the study area, the basic profile data includes: pipeline profile, working face profile and study area profile; the study area profile is combined with the measured data to obtain predicted parameters, and the predicted parameters are combined with the working face profile to obtain the coal seam mining direction; the subsidence of the sub-high pressure gas pipeline to be tested at multiple angles with the coal seam mining direction is predicted by a predicted model to obtain the surface movement deformation value; Fourier fitting is performed on the surface movement deformation value to obtain a fitting function, and the boundary conditions of the study area are input into the fitting function to obtain the failure criterion of the sub-high pressure gas pipeline to be tested; and the mining damage of the sub-high pressure gas pipeline to be tested is judged according to the failure criterion.

[0041] Compared with the existing technology, the above technical solution predicts the subsidence of the surface around the sub-high-pressure gas pipeline to be tested from multiple angles through the prediction model, takes into account the problem of multiple spatial intersections between the working face layout and the pipeline, and determines the surface movement deformation value of the sub-high-pressure gas pipeline along the coal seam mining direction; then Fourier fitting is performed on the surface movement deformation value to obtain the fitting function, and the boundary conditions of the study area are input into the fitting function to obtain the failure criterion of the sub-high-pressure gas pipeline to be tested, and the mining damage of the sub-high-pressure gas pipeline to be tested is determined according to the failure criterion. Therefore, it is possible to quickly determine whether the sub-high-pressure gas pipeline is in a safe state, ensuring the safety and stability of the coal seam mining process. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention is a flow chart of a method for determining whether coal mining will affect the next mining damage of a high-pressure gas pipeline provided in an embodiment. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] In one embodiment, a method for determining whether coal mining will affect the next high-pressure gas pipeline mining damage is provided, such as Figure 1 As shown, the method includes:

[0045] 1. Obtain the basic overview data and measured data of the study area where the sub-high pressure gas pipeline to be tested is laid. The basic overview data includes the overview of the study area, the overview of the working surface and the boundary conditions, and the measured data characterizes the properties of the sub-high pressure gas pipeline to be tested.

[0046] 2. According to the relationship between the direction of the study area profile and the measured data, determine the expected direction of the numerical simulation of the sub-high pressure gas pipeline to be tested. Compare the expected direction with the mining direction reflected by the working face profile to determine the coal seam mining direction in the study area.

[0047] 3. Construct a prediction model, and use it to predict the subsidence of the surface around the sub-high-pressure gas pipeline to be tested at multiple angles, and obtain the surface movement deformation value of the sub-high-pressure gas pipeline to be tested along the coal seam mining direction.

[0048] 3.1 The impact of mining damage on the surface around the high-pressure gas pipeline in the direction of coal seam mining. The influencing factors are divided into pipeline laying factors and underground factors.

[0049] Pipeline laying factors include: pipeline material and working surface conditions. Pipeline material includes: strength, stiffness, toughness and diameter-thickness ratio, and working surface conditions include working surface size.

[0050] Underground factors include: site conditions, mining conditions and burial methods. Site conditions include soil mechanical parameters and backfill properties, mining conditions include inclination, direction and speed, and burial methods include laying methods and burial depth.

[0051] 3.2 The prediction model is used to characterize the influence of mining damage on the surface around the sub-high pressure gas pipeline to be tested in the direction of coal seam mining, which specifically includes: geometric model and constitutive model.

[0052] The geometric model describes the physical shape and spatial structure of an object and is the basis for constructing the computational domain in numerical analysis. The geometric model usually includes basic elements such as points, lines, surfaces, and bodies, and these basic elements and their combinations are used to represent the geometric shape of the actual object.

[0053] The constitutive model describes the stress-strain relationship of a material under external forces and is a mathematical model that simulates the mechanical behavior of a material. Different materials exhibit different mechanical properties under different stress states, such as elasticity, plasticity, creep, fracture, etc. The constitutive model is used to capture these properties.

[0054] (1) Geometric model construction

[0055] The length of the pipeline model is set to 2000m, and the buried depth of the pipeline is set to 3m. The size of the soil model (length × height × width) is: 2000m × 6m × 6m. The construction of the pipeline geometry model and the soil geometry model is all achieved by stretching the solid unit.

[0056] (2) Construction of constitutive model

[0057] The pipe-soil interaction in the subsidence soil is mainly the constitutive relationship between the buried pipeline and the soil around the pipeline, that is, setting accurate and reasonable material properties for the pipeline and soil components. The buried pipeline is generally a homogeneous material, and its constitutive relationship is relatively simple. The soil around the pipe is a non-homogeneous anisotropic material, and its constitutive relationship is relatively complex.

[0058] A. Pipeline constitutive model

[0059] The relationship curve between pipeline strain and stress goes through four stages: elastic stage, yield stage, strengthening stage and necking stage. In these stages, the pipeline shows obvious elastic-plastic and yield hardening phenomena. The linear elastic model is used to characterize the strain of the sub-high pressure gas pipeline to be tested in multiple stages.

[0060] B. Soil constitutive model

[0061] In addition to its elastic properties, soil also undergoes certain plastic deformation when subjected to stress and deformation. Therefore, in the construction of soil constitutive model engineering, it is necessary to define the elastic and plastic properties of soil separately.

[0062] For the elastic part of the soil, a linear elastic model is used, which is described by the Poisson's ratio and elastic modulus of the soil.

[0063] For the plastic part of the soil, the Mohr-Coulomb model is used as the soil plasticity model, which is suitable for granular materials under monotonic loading.

[0064] The Mohr-Coulomb model is a mathematical model used to describe the response of brittle materials (such as concrete or rubble) under shear stress and normal stress. The model assumes that the damage is caused by the maximum shear stress, which is related to the normal stress. That is, the Mohr circles representing the damage state are drawn on the maximum principal stress plane and the minimum principal stress plane. The expression of the contact line between the two Mohr circles is:

[0065]

[0066] Among them, τ max is the maximum shear stress, σ mis the average principal stress, c is the cohesion of the material, is the internal friction angle of the material.

[0067] 3.3 When predicting the subsidence of the ground around the sub-high pressure gas pipeline to be tested through the prediction model, multiple angles are included, specifically including the subsidence prediction when the sub-high pressure gas pipeline to be tested is at 0°, 15°, 45°, 60°, 75° and 90° to the coal seam mining direction.

[0068] (1) The displacement deformation of the pipeline in the mining subsidence area is simulated by applying displacement load. Since the mining depth of the working face is as high as 970m, it can be considered that the movement deformation law of the soil on the surface and within 3 meters of the surface is consistent with the settlement deformation value, that is, the settlement deformation of the surface and the deformation of the underground pipeline obtained by calculation are roughly the same as the soil deformation 3 meters underground.

[0069] (2) Treat the pipeline as a simple linear elastic model. Ignore the pipeline joints. For pipelines connected by welding, hot melt or rigid bolts, the strength and stiffness of the joints are at least the same as the pipeline itself. This type of pipeline can be regarded as a continuous beam.

[0070] (3) Since the transport medium is natural gas, its own weight can be ignored.

[0071] (4) The soil within the model calculation range is regarded as a single homogeneous soil, and the influence of soil stratification is not considered.

[0072] 4. Perform Fourier fitting on the ground movement deformation value to obtain a fitting function, which is used to determine the stress condition of the sub-high pressure gas pipeline after being damaged by mining.

[0073] Fourier fitting is a common method for mathematical analysis. The basic idea is to represent the value and the mapping value as a linear combination of a set of sine and cosine functions. The surface displacement deformation values ​​in the east-west, north-south and vertical directions of the surface during mining are fitted by the Fourier eight-parameter fitting method to obtain the corresponding displacement distribution curve. The detailed process of Fourier eight-parameter fitting in MATLAB is as follows:

[0074] (1) East-west and north-south displacement curves: These curves will reflect the horizontal movement of the ground around the sub-high pressure gas pipeline to be tested, which may appear as a wave or sinusoidal curve. Due to the impact of mining activities on the strata, the displacement may appear to gradually increase to a certain extreme value and then gradually decrease.

[0075] (2) The expansion formula of the Fourier eight-parameter series is:

[0076]

[0077] Among them, a0, an , b n is the Fourier coefficient, x is the position of the point, and N is the order of the expansion.

[0078] (3) Displacement curve in the vertical direction (y direction): This part of the curve shows the subsidence or uplift of the ground around the sub-high pressure gas pipeline to be tested. The vertical displacement curve may appear as a typical "U" or "V" shape, reflecting the subsidence or uplift of the ground at different locations.

[0079] When performing numerical simulation in Abaqus, the displacement distribution curve obtained by Fourier eight-parameter fitting can be applied to the analytical field as an initial condition or boundary condition. That is, these displacement curves are used as boundary conditions, and Abaqus will calculate the stress and strain distribution in the model, as well as the corresponding surface deformation according to these displacement conditions. The simulation results will reflect the deformation morphology of the surface in the horizontal and vertical directions. The displacement and stress distribution obtained by simulation will be consistent with the Fourier fitting curve in morphology, but the numerical simulation will further consider complex factors such as material properties, boundary conditions, loading conditions, etc., so as to obtain a more accurate displacement and stress field distribution.

[0080] 5. Input the boundary conditions of the study area into the fitting function to obtain the failure criterion of the sub-high pressure gas pipeline to be tested.

[0081] In the engineering simulation software Advanced Simulation for Engineering and Sciences (ABAQUS), the fitting function input in the form of analytical field can be used to define the material properties, boundary conditions, loads, etc. that vary with spatial coordinates. The analytical field can be implemented by user-defined functions. Here, the specific steps are introduced using the Fourier eight-parameter fitting function as an example.

[0082] 1) Define the analytical field

[0083] Firstly, based on the displacement monitoring data of the mining area, the displacement distribution curves in the east-west, north-south and vertical directions were fitted using the Fourier eight-parameter fitting method.

[0084] 2) Apply boundary conditions

[0085] In order to ensure the symmetry of the non-sinking area, the segmentation boundaries of these areas are set to fixed three-dimensional degrees of freedom (the degrees of freedom in the x, y, and z directions are all set to 0). This ensures that the segmentation boundaries will not move during the sinking deformation. In order to achieve the slight horizontal movement and vertical sinking of the pipeline and soil in the sinking area, the degrees of freedom of the lateral boundaries (z and y directions) at both ends of the model are set to 0 to limit the displacement in these directions. At the same time, the degrees of freedom in the z and x directions of the bottom boundary of the model are also set to 0 to ensure the stability of the bottom of the fitting function.

[0086] 3) Apply analytical field

[0087] The fitting functions are input as analytical fields into the engineering simulation software ABAQUS. These functions are applied to the relevant parts by specifying the corresponding boundary conditions. The engineering simulation software ABAQUS will calculate the stress and strain in the model based on these displacement fields.

[0088] 4) Run the simulation

[0089] Perform numerical simulation, and the engineering simulation software ABAQUS will calculate the surface subsidence displacement and stress distribution according to the defined analytical field and boundary conditions.

[0090] 5) Simulation results

[0091] Obtain the failure criteria of the sub-high pressure gas pipeline to be tested, which specifically include:

[0092] A. Surface displacement distribution: The surface displacement distribution curves around the sub-high pressure gas pipeline to be tested in the east-west, north-south and vertical directions match the Fourier fitting curve.

[0093] B. Stress distribution: The engineering simulation software ABAQUS can also calculate the stress distribution in the soil and pipeline, especially the stress concentration in the subsidence area and the stress condition of the pipeline.

[0094] C. Pipeline deformation: By fixing the boundaries of the non-sinking area and appropriately setting the boundary conditions at both ends of the pipeline, the simulation will show the overall deformation and stress conditions of the sub-high pressure gas pipeline to be tested after being damaged by mining.

[0095] 6. Determine the mining damage of the sub-high pressure gas pipeline to be tested based on the failure criteria.

[0096] For example, take the protection of a medium-high pressure gas pipeline in a mining area. Multiple working faces in the mining area are under the buried gas pipeline. If no protective measures are taken for mining, the safe operation of the pipeline will be greatly affected. Some mining measures have caused great waste of coal resources. If the contradiction between pipeline coal pressure and coal mining is not resolved, the mining of subsequent working faces in the mining area will be seriously affected.

[0097] The engineering simulation software ABAQUS was used to establish a pipe-soil numerical model of the goaf, including geometric model, constitutive model, pipe-soil contact settings and model boundary conditions. The mechanical response of the working face mining direction and pipeline at different angles (0 to 90 degrees) was analyzed to determine the most unfavorable working face layout direction. The influence of different burial methods on the pipeline was studied to determine the most unfavorable burial conditions. The strain-based pipeline failure criterion was used to determine the critical value of surface deformation for pipeline damage. Combined with the engineering geological conditions and pipeline conditions, underground and ground coordinated management measures were proposed, including working face planning, pipeline monitoring, pipeline lifting, etc.

[0098] By studying the interaction between buried pipelines and soil in mining areas, and exploring the response mechanism and control measures of buried pipeline mining damage, we can solve the contradiction of mining in a certain mining area affecting gas pipelines, protect the operational safety of overlying gas pipelines, solve the problem of mining coal under pipelines, and further enrich and develop the theoretical system of mining damage and protection.

[0099] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage. It is characterized in that include: Obtain basic overview data and measured data of the research area where the sub-high pressure gas pipeline to be tested is laid; The basic profile data include the profile of the study area, the profile of the working face and the boundary conditions; According to the directional relationship between the overview of the study area and the measured data, the expected direction of the numerical simulation of the sub-high pressure gas pipeline to be tested is determined; the expected direction is compared with the mining direction reflected by the overview of the working face to determine the mining direction of the coal seam in the study area; Constructing a prediction model, the prediction model is used to characterize the influence of mining damage on the surface around the sub-high pressure gas pipeline to be tested in the direction of coal seam mining; using the prediction model to predict the subsidence of the surface around the sub-high pressure gas pipeline to be tested at multiple angles, and obtaining the surface movement deformation value of the sub-high pressure gas pipeline to be tested along the direction of coal seam mining; Perform Fourier fitting on the ground surface movement deformation value to obtain a fitting function, wherein the fitting function is used to determine the stress condition of the sub-high pressure gas pipeline after it is damaged by mining; The boundary conditions of the study area are input into the fitting function to obtain the failure criterion of the sub-high pressure gas pipeline to be tested, and the mining damage of the sub-high pressure gas pipeline to be tested is determined according to the failure criterion.

2. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 1, It is characterized in that The prediction model includes a geometric model and a constitutive model; The geometric model includes a pipeline geometric model representing the size of the sub-high pressure gas pipeline and a soil geometric model representing the terrain conditions around the pipeline; The constitutive model includes a pipeline constitutive model and a soil constitutive model; The pipeline constitutive model is a linear elastic model, which is used to reflect the strain conditions of the sub-high pressure gas pipeline to be tested in the elastic stage, yield stage, strengthening stage and necking stage of the pipeline strain and stress relationship curve; The soil constitutive model includes: for the elastic part of the soil, a linear elastic model is used as the soil constitutive model; for the plastic part of the soil, a Mohr-Coulomb model is used as the soil plastic model and also as the soil constitutive model.

3. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 2, It is characterized in that The Mohr-Coulomb model is a mathematical model used to describe the response of brittle materials under shear stress and normal stress, and its expression is: Draw Mohr circles representing the failure state on the maximum principal stress plane and the minimum principal stress plane. The expression of the contact line between the two Mohr circles is: Among them, τ max is the maximum shear stress, σ m is the average principal stress, c is the cohesion of the material, is the internal friction angle of the material.

4. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 1, It is characterized in that The influence of mining damage on the surface around the sub-high pressure gas pipeline in the direction of coal seam mining, and the influencing factors are divided into pipeline laying factors and underground factors; The pipeline laying factors include: pipeline materials and working surface conditions; The pipeline material includes: strength, stiffness, toughness and diameter-to-thickness ratio; The working surface conditions include working surface dimensions; The underground factors include: site conditions, mining conditions and burial methods; The site conditions include soil mechanical parameters and backfill soil properties; The mining conditions include dip, direction and velocity; The embedding method includes a laying method and an embedding depth.

5. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 1, It is characterized in that The subsidence prediction of the ground surface around the sub-high pressure gas pipeline to be tested by the prediction model includes multiple angles, specifically including subsidence prediction of the sub-high pressure gas pipeline to be tested at 0°, 15°, 45°, 60°, 75° and 90° to the coal seam mining direction.

6. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 1, It is characterized in that The Fourier fitting of the ground surface movement deformation value specifically includes: The east-west, north-south and vertical displacement distribution curves of the sub-high-pressure gas pipeline to be tested are obtained by fitting the surface deformation values ​​of the east-west, north-south and vertical directions of the sub-high-pressure gas pipeline to be tested during mining through the expansion formula of the Fourier eight-parameter series. The expansion formula of the Fourier eight-parameter series is: Among them, a 0 、a n and b n is the Fourier coefficient, x is the position of the point, and N is the order of expansion; The east-west displacement distribution curve, the north-south displacement distribution curve and the vertical displacement distribution curve are used as boundary conditions, and the stress, strain distribution and force conditions of the sub-high pressure gas pipeline to be tested are calculated according to the boundary conditions.

7. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 6, It is characterized in that The east-west displacement distribution curve and the north-south displacement distribution curve of the sub-high pressure gas pipeline to be tested are used to reflect the horizontal movement of the ground surface around the sub-high pressure gas pipeline to be tested; The vertical displacement distribution curve of the sub-high pressure gas pipeline to be tested is used to characterize the vertical subsidence or uplift of the ground surface around the sub-high pressure gas pipeline to be tested.

8. A method for determining the impact of coal mining on the next high-pressure gas pipeline mining damage as claimed in claim 1, It is characterized in that The failure criteria of the sub-high pressure gas pipeline to be tested include surface displacement distribution, stress distribution and pipeline deformation.

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