A method for calculating the failure probability of a buried hydrogen-doped pipeline with defects

Abstract

The present invention discloses a method for calculating the failure probability of a buried hydrogen-doped pipeline with defects, which relates to the field of pipeline failure probability calculation, and obtains the maximum hoop stress and maximum longitudinal strain generated by the buried pipeline under the impact load; obtains the ultimate bearing capacity P of the buried pipeline in the defective hydrogen pipeline; b ; According to the ultimate bearing capacity P of the defective hydrogen pipeline b , obtain the yield stress of the buried pipeline; obtain the limit state parameters of the buried pipeline according to the maximum hoop stress, the maximum longitudinal strain and the yield stress; determine whether the buried pipeline has failed according to the limit state parameters; collect the pipeline failure data, and obtain the failure probability P1 of the buried pipeline according to the pipeline failure data. The present invention fully considers the interaction between the transport medium and soil of the defective buried hydrogen pipeline, as well as the influence of multiple factors such as external load on the failure probability of the pipeline, and can quickly and effectively analyze the failure probability of the defective buried hydrogen pipeline.

Description

Technical Field

[0001] The invention relates to the field of pipeline failure probability calculation, and in particular to a method for calculating the failure probability of a defective buried hydrogen-doped pipeline. Background Art

[0002] Due to the vast territory, complex terrain, and the earthquake-prone areas in my country, natural disasters such as earthquakes and landslides and rockfalls in complex mountainous environments always threaten the safety of long-distance pipelines. In order to meet the energy needs of various regions, long-distance gas pipelines are widely distributed in working conditions with complex geographical conditions and geological environments, and will inevitably be affected by the impact of rockfalls caused by earthquakes, landslides, etc. In the normal service of gas pipeline projects, many cases of rockfalls damaging gas pipelines have occurred in various regions at home and abroad. At the same time, the utilization rate of renewable energy has gradually increased. Among them, hydrogen energy, as a clean and efficient renewable energy, has been proposed to be mixed with natural gas for transportation as the most effective method. Compared with natural gas transportation pipelines, hydrogen will gradually adsorb on the inner wall of the pipeline, causing certain effects on the pipeline material, such as hydrogen-induced cracks, hydrogen blistering, hydrogen embrittlement and other forms of damage, thereby causing changes in pipeline performance.

[0003] Impact load is an important factor affecting pipeline safety. Traditional calculation methods do not take into account the impact of the ultimate bearing capacity pressure in the defective hydrogen pipeline. This may lead to overly conservative results. Therefore, it is necessary to determine a fast and effective technology to analyze the probability of pipeline structure failure. Studies have shown that for defective pipelines, hydrogen atoms tend to gather in places such as weld defects after doping. As the pipeline pressure fluctuates during transportation, the properties of the pipeline where hydrogen atoms gather change, and the bearing stress itself also changes, thus affecting the service life of the pipeline. Therefore, it is necessary not only to fully consider the pipe-soil interaction and external load effects, but also to take into account the self-generated working state and performance state of the pipeline, and conduct pipeline reliability analysis based on the joint action of multiple factors.

[0004] However, in the prior art, the failure status assessment method and conditions for buried gas pipelines are single, and the factors considered are single. Therefore, when calculating the failure probability, the working state and performance state of the pipeline are often sacrificed to ensure the safe operation of the pipeline. Based on this, the present application provides a method for calculating the failure probability of a buried pipeline based on the combined effect of multiple factors under the action of an external load. Summary of the invention

[0005] The present invention provides a method for calculating the failure probability of a defective buried hydrogen-doped pipeline, aiming at fully considering the failure probability analysis of the buried pipeline under the combined effects of multiple factors such as the transport medium-soil interaction and external load.

[0006] To achieve the above-mentioned purpose, the present invention provides a method for calculating the failure probability of a buried hydrogen-doped pipeline containing defects, comprising the following steps: S1, obtaining the maximum hoop stress σ1 and the maximum longitudinal strain σ2 generated by the buried pipeline under the impact load;

[0007] S2, obtain the ultimate bearing capacity P of the buried pipeline in the hydrogen pipeline with defects b ;

[0008] S3, according to the ultimate bearing capacity P of the defective hydrogen pipeline b , obtain the yield stress σ of the buried pipeline s ;

[0009] S4, based on the maximum hoop stress σ1, maximum longitudinal strain σ2 and yield stress σ s Obtain the limit state parameter σ of buried pipeline t ;

[0010] S5, according to the limit state parameter σ t Determine whether the buried pipeline has failed;

[0011] S6, repeat S1-S5, count the pipeline failure data, and obtain the failure probability of the buried pipeline based on the pipeline failure data .

[0012] Among them, the damage caused by the impact of falling rocks to the structure is mainly studied by studying the impact force calculation method and the dynamic response of the structure during the impact process.

[0013] At the same time, although high-purity hydrogen is not corrosive to pipelines, the original corrosion defects that may exist in natural gas pipelines when transporting hydrogen must be considered, because for steel pipelines, inner wall corrosion is almost an inevitable phenomenon. Corrosion defects will cause the pipe wall to become thinner, thereby weakening the bearing capacity of the pipeline. Once the internal pressure of the transmission reaches the ultimate bearing capacity of the defective hydrogen pipeline in the corroded pipeline, it may cause serious accidents such as leakage and explosion.

[0014] Combined with the rockfall impact and the failure assessment method of the defective hydrogen pipeline, the present invention combines the rockfall impact and the failure assessment of the defective hydrogen pipeline to obtain the yield stress σ of the pipeline. s , further ensuring the safe and reliable operation of the hydrogen pipeline.

[0015] Specifically, according to the maximum hoop stress σ1, the maximum longitudinal strain σ2 and the yield stress σ s Obtain the limit state parameter σ of buried pipeline t , where the yield stress σ of the buried pipeline is s The calculation formula is as follows:

[0016] ;

[0017] Among them, P b It is the ultimate bearing capacity of the hydrogen pipeline with defects.

[0018] Obtain the limit state parameter σ t The calculation formula is as follows:

[0019] ;

[0020] in, is the design coefficient.

[0021] The yield stress σ of the existing buried pipeline s Compared with the calculation formula of s is a constant, and the present invention combines the rockfall impact and the failure assessment of the defective hydrogen pipeline to calculate the yield stress σ of the buried pipeline. s The calculation formula is improved to obtain a failure probability analysis of buried pipelines under the combined action of multiple factors such as transmission medium-soil interaction and external loads, which can quickly and effectively analyze the failure probability of buried hydrogen pipelines with defects.

[0022] Among them, the calculation formula of the maximum hoop stress σ1 is as follows:

[0023] ;

[0024] Where, E is the elastic modulus of the pipeline, k is the bending coefficient, K is the base coefficient, s is the pipeline wall thickness, P is the pipeline working pressure, ρ is the soil density; D is the pipeline diameter, H is the pipeline burial depth, and g is the gravity acceleration; when grooving is used, k=0.108, K=0.235; when drilling is used, k=0.096, K=0.157.

[0025] q1 is the vertical force on the buried pipeline under the impact load. The calculation formula of q1 is as follows:

[0026] ;

[0027] Among them, F is the impact load and f is the penetration coefficient.

[0028] The method for obtaining the maximum longitudinal strain σ2 includes the following steps:

[0029] Obtain the normal force F on the buried pipeline under the impact load N The calculation formula is as follows:

[0030] ;

[0031] Where D is the pipe diameter, h is the soil thickness, ρ is the soil density, a is the width of the load, b is the length of the load, μ D is the load dynamic coefficient, H is the buried depth of the pipeline, and F is the impact load;

[0032] Obtain the lateral load q of the buried pipeline L The calculation formula is as follows:

[0033]

[0034] in, is the friction angle of the soil, s is the pipe wall thickness, and g is the gravitational acceleration;

[0035] The calculation formula for obtaining the maximum bending moment M of the buried pipeline is as follows:

[0036]

[0037] The calculation formula for obtaining the maximum longitudinal strain σ2 is as follows:

[0038] ;

[0039] Where P is the pipeline working pressure.

[0040] Furthermore, in S5, when σ t = 0, the pipeline is in the limit state; when σ t <0, the pipeline has not failed; when σ t When >0, the pipeline fails.

[0041] In S6, the failure probability The calculation formula is as follows:

[0042]

[0043] Where N is the total number of repetitions of S1-S5, and m is σ t >0 number of occurrences.

[0044] Furthermore, the calculation formula of the impact load F is as follows:

[0045]

[0046] Among them, m1 is the mass of the rockfall, E1 and E2 are the elastic moduli of the rockfall and soil respectively, μ1 and μ2 are the Poisson's ratios of the rockfall and soil respectively, r1 is the radius of the rockfall, and v is the rockfall velocity.

[0047] The calculation formula of rockfall velocity v is as follows:

[0048]

[0049] or,

[0050] Among them, h1 is the initial height of the rockfall, g is the acceleration of gravity, v0 is the initial velocity of the rockfall, f1 is the sliding friction coefficient, and b1 is the inclination angle of the slope.

[0051] Corresponding to the method in the present invention, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for calculating the failure probability of a defective buried hydrogen-doped pipeline are implemented.

[0052] Corresponding to the method in the present invention, the present invention also provides a storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the above-mentioned method for calculating the failure probability of a defective buried hydrogen-doped pipeline are implemented.

[0053] One or more technical solutions provided by the present invention have at least the following technical effects or advantages: the present invention fully considers the interaction between the transport medium and soil of a defective buried hydrogen pipeline, as well as the influence of multiple factors such as external loads on the failure probability of the pipeline, and can quickly and effectively analyze the failure probability of a defective buried hydrogen pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0055] Figure 1 The figure is a flow chart of a method for calculating the failure probability of a buried hydrogen-doped pipeline with defects. DETAILED DESCRIPTION

[0056] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0057] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those within the scope of this description. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0058] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0059] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0060] Example 1

[0061] Please refer to Figure 1 , Figure 1 The present invention provides a method for calculating the failure probability of a buried hydrogen-doped pipeline containing defects, and the method comprises:

[0062] S1, the impact load in this application is the impact load under the action of falling rocks;

[0063] S11, when the motion mode of the falling rock is free fall, the calculation formula of the falling rock velocity v is as follows:

[0064]

[0065] Among them, h1 is the initial height of the rockfall, and g is the acceleration due to gravity.

[0066] Or, when the motion mode of the falling rock is sliding, the calculation formula of the falling rock velocity v is as follows:

[0067]

[0068] Among them, v0 is the initial velocity of the falling rock, f1 is the sliding friction coefficient, and b1 is the inclination angle of the inclined plane.

[0069] S12, calculate the impact load F according to the rockfall velocity v. The calculation formula of the impact load F is as follows:

[0070]

[0071] Among them, m1 is the mass of the rockfall, E1 and E2 are the elastic moduli of the rockfall and soil respectively, μ1 and μ2 are the Poisson's ratios of the rockfall and soil respectively, r1 is the radius of the rockfall, and v is the rockfall velocity.

[0072] S13, calculate the vertical force q1 on the buried pipeline under the impact load of falling rocks according to the impact load F. The calculation formula of the vertical force q1 is as follows:

[0073]

[0074] Where D is the pipe diameter, H is the buried depth of the pipe, F is the rockfall impact load, and f is the penetration coefficient.

[0075] S14, calculate the maximum hoop stress σ1 based on the vertical force q1. The calculation formula of the maximum hoop stress σ1 is as follows:

[0076]

[0077] Where, E is the elastic modulus of the pipeline, k is the bending coefficient, K is the base coefficient, s is the pipeline wall thickness, P is the pipeline working pressure, ρ is the soil density; D is the pipeline diameter, H is the pipeline burial depth, and g is the gravity acceleration; when grooving is used, k=0.108, K=0.235; when drilling is used, k=0.096, K=0.157.

[0078] S15, obtain the lateral load q of the buried pipeline L , lateral load q of buried pipeline L The calculation formula is as follows:

[0079]

[0080] in, is the friction angle of the soil, s is the pipe wall thickness, and g is the gravitational acceleration;

[0081] S16, obtaining the maximum bending moment M of the buried pipeline. The calculation formula of the maximum bending moment M of the buried pipeline is as follows:

[0082]

[0083] Where D is the pipe diameter, h is the soil thickness, ρ is the soil density, a is the width of the load, b is the length of the load, μ D is the load dynamic coefficient, H is the buried depth of the pipeline, and F is the impact load;

[0084] S17, obtain the maximum longitudinal strain σ2, the calculation formula of the maximum longitudinal strain σ2 is as follows:

[0085] ;

[0086] Among them, P is the working pressure of the pipeline and a is the width of the load.

[0087] S2, obtain the ultimate bearing capacity P of the buried pipeline in the hydrogen pipeline with defects b ;

[0088] Based on the current situation of large-scale construction of hydrogen pipelines, it is of great significance to establish a prediction formula for the ultimate bearing capacity and a failure assessment method for corroded hydrogen pipelines containing defects, including hydrogen damage factors.

[0089] S21, the calculation formula of the ultimate bearing capacity Pb ​​in the defective hydrogen pipeline is as follows:

[0090]

[0091] Among them, σ flow is the rheological stress, i.e. the yield limit of the complete hydrogen pipeline under certain conditions. represents the corrosion width, d represents the corrosion depth, Y represents the corrosion length, s represents the pipe wall thickness, D represents the pipe diameter, Ds represents the product of the pipe wall thickness and the diameter, and a1-a8 represents the dimensionless ultimate bearing capacity P b / (2σ flow s / D) and the coefficients in the relationship curves of the four dimensionless parameters. flow s / D is the ultimate bearing pressure of the complete hydrogen pipeline.

[0092] The four dimensionless parameters are corrosion length, corrosion width, corrosion depth, and pipeline diameter-to-thickness ratio.

[0093] Among them, the relationship change curve is the existing fitting curve. Generally speaking, the ultimate bearing capacity Pb ​​and yield stress σ in the defective hydrogen pipeline s For existing data.

[0094] S3, according to the ultimate bearing capacity P of the defective hydrogen pipeline b , obtain the yield stress σ of the buried pipeline s ;

[0095] Yield stress σ of buried pipeline s The calculation formula is as follows:

[0096] .

[0097] S4, based on the maximum hoop stress σ1, maximum longitudinal strain σ2 and yield stress σ s Obtain the limit state parameter σ of buried pipeline t ;

[0098] Obtain the limit state parameter σ t The calculation formula is as follows:

[0099] ;

[0100] in, is the design coefficient.

[0101] S5, according to the limit state parameter σ t Determine whether the buried pipeline has failed;

[0102] When σ t =0, the pipeline is in the limit state;

[0103] When σ t When <0, the pipeline has not failed;

[0104] When σ t When >0, the pipeline fails.

[0105] S6, repeat S1-S5, count the pipeline failure data, and obtain the failure probability of the buried pipeline based on the pipeline failure data .

[0106] S61, failure probability The calculation formula is as follows:

[0107]

[0108] Where N is the total number of times S1-S5 are repeated, and m is σ t >0 number of occurrences.

[0109] Finally, this embodiment 1 introduces a method for calculating the failure probability of a defective buried hydrogen-doped pipeline in the present invention with a specific example:

[0110] The gas pipeline in a certain place was laid through a valley. Due to the earthquake, the mountain broke and there were falling rocks concentrated above the pipeline. The average buried depth H of the pipeline was 0.9m, and the elastic modulus E of the pipeline was 155MPa. The surface load of the pipeline soil, the soil density ρ is 1830kg / m3, the elastic modulus E1 of the falling rocks is 18MPa, the Poisson's ratio μ1 is 0.25, and the friction angle of the soil is 21°. Slotting is adopted, k=0.108, K=0.235; the load range is length: 0.2m, width: 0.5m, and the design parameters in this example are taken as 0.8.

[0111] The falling rock is in free fall, with a mass m1 of 100 kg, a radius r1 of 0.5 m, and an initial height h1 of 3 m.

[0112] The soil elastic modulus E2 and Poisson's ratio μ2 vary according to the soil type. For medium-hard saturated clay, the elastic modulus E2 is 0.6 MPa and the Poisson's ratio μ2 is 0.5. The data of the pipeline are shown in Table 1.

[0113] Table 1

[0114]

[0115] A finite element model of hydrogen and natural gas pipelines with internal corrosion defects was established, and the riks method was used for nonlinear analysis. The Mises stress data of the pipeline under different internal pressure loads were extracted in the post-processing interface. The Mises stress of the hydrogen pipeline basically did not change after yielding. When the internal pressure load reached 16.26MPa, the Mises stress reached the true ultimate tensile strength of the pipeline steel in the hydrogen environment (678.43MPa). It can be seen that the ultimate bearing capacity of the hydrogen pipeline with corrosion defects is 16.26MPa.

[0116] Among them, the Riks method, also known as the arc length method, is an iterative control method widely used in structural nonlinear analysis. It is often used in finite element software to solve material nonlinearity, geometric nonlinearity, pre-buckling or unstable post-buckling response problems.

[0117] Mises stress, also known as Mises stress, is an equivalent stress that follows the fourth strength theory of material mechanics (shape change specific energy theory). For most plastic materials, this is needed for strength verification.

[0118] According to Table 1, the normal distribution function of each variable parameter is established, and 100,000 data are taken from each, that is, the calculation is repeated N=100,000 times, and each calculation is calculated according to the calculation formula in the present invention. First, the movement mode of the rockfall is determined, and the falling speed is calculated. The force of the rockfall impact load on the pipeline, the force of the soil on the pipeline, the circumferential force on the pipeline, the maximum axial stress of the pipeline, and the ultimate bearing capacity pressure of the pipeline containing defects in the hydrogen transmission pipeline are calculated respectively; based on the above data, the pipeline limit state coefficient σ is calculated. t ;Record limit state coefficient σ t >0 for m times, and finally the failure probability obtained in this embodiment is 0.33.

[0119] Based on the simulation results of finite element calculation, the yield stress σ of the buried pipeline is fitted. s The formula is proposed, and a calculation method for the failure probability of a buried hydrogen pipeline containing defects is proposed based on the interaction between the transmission medium and soil, as well as external loads and other factors.

[0120] Example 2

[0121] Based on this embodiment, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for calculating the failure probability of a defective buried hydrogen-blended pipeline are implemented.

[0122] The processor may be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0123] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the method for calculating the failure probability of a buried hydrogen-doped pipeline containing defects in the invention by running or executing the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.). In addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card, a secure digital card, a flash memory card, at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0124] Example 3

[0125] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method for calculating the failure probability of a defective buried hydrogen-doped pipeline are implemented.

[0126] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, but is not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0127] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0128] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for calculating the failure probability of a buried hydrogen-doped pipeline containing defects, characterized in that: The following steps are involved: S1, obtain the maximum hoop stress σ1 and maximum longitudinal strain σ2 generated by the buried pipeline under the impact load; S2, obtain the ultimate bearing capacity P of the buried pipeline in the hydrogen pipeline with defects b ; S3, according to the ultimate bearing capacity P of the defective hydrogen pipeline b , obtain the yield stress σ of the buried pipeline s ; S4, based on the maximum hoop stress σ1, maximum longitudinal strain σ2 and yield stress σ s Obtain the limit state parameter σ of buried pipeline t ; S5, according to the limit state parameter σ t Determine whether the buried pipeline has failed; S6, repeat S1-S5, count the pipeline failure data, and obtain the failure probability P1 of the buried pipeline based on the pipeline failure data; the yield stress σ of the buried pipeline s The calculation formula is as follows: s s =0.25P b 2 +41.67P b -10.97 The calculation formula of the maximum hoop stress σ1 is as follows: Where, E is the elastic modulus of the pipeline, k is the bending coefficient, K is the base coefficient, s is the pipeline wall thickness, P is the pipeline working pressure, ρ is the soil density; D is the pipeline diameter, H is the pipeline burial depth, and g is the gravitational acceleration; q1 is the vertical force on the buried pipeline under the impact load. The calculation formula of q1 is as follows: Among them, F is the impact load, f is the penetration coefficient; The method for obtaining the maximum longitudinal strain σ2 includes the following steps: Obtain the normal force F on the buried pipeline under the impact load N The calculation formula is as follows: Where D is the pipe diameter, h is the soil thickness, ρ is the soil density, a is the width of the load, b is the length of the load, μ D is the load dynamic coefficient, H is the buried depth of the pipeline, and F is the impact load; Obtain the lateral load q of the buried pipeline L The calculation formula is as follows: in, is the friction angle of the soil, s is the pipe wall thickness, and g is the gravitational acceleration; The calculation formula for obtaining the maximum bending moment M of the buried pipeline is as follows: The calculation formula for obtaining the maximum longitudinal strain σ2 is as follows: Wherein, P is the pipeline working pressure; Ultimate bearing capacity P in hydrogen pipeline with defects b The calculation formula is as follows: Among them, σ flow is the rheological stress, i.e. the yield limit of the complete hydrogen pipeline under certain conditions. represents the corrosion width, d represents the corrosion depth, Y represents the corrosion length, s represents the pipe wall thickness, D represents the pipe diameter, Ds represents the product of the pipe wall thickness and the diameter, and a1-a8 represents the dimensionless ultimate bearing capacity P b / (2σ flow s / D) and the coefficients of the relationship curves of the four dimensionless parameters; 2σ flow s / D is the ultimate bearing pressure of the complete hydrogen pipeline.

2. The method for calculating the failure probability of a defective buried hydrogen-doped pipeline according to claim 1, characterized in that: Obtain the limit state parameter σ t The calculation formula is as follows: in, is the design coefficient.

3. The method for calculating the failure probability of a defective buried hydrogen-doped pipeline according to claim 1, characterized in that: In S5, when σ t = 0, the pipeline is in the limit state; when σ t <0, the pipeline has not failed; when σ t When >0, the pipeline fails.

4. The method for calculating the failure probability of a defective buried hydrogen-doped pipeline according to claim 1, characterized in that: In S6, the calculation formula of failure probability P1 is as follows: Where N is the total number of times S1-S5 are repeated, and m is σ t >0 number of occurrences.

5. The method for calculating the failure probability of a defective buried hydrogen-doped pipeline according to claim 1, characterized in that: The calculation formula of impact load F is as follows: Among them, m1 is the mass of the rockfall, E1 and E2 are the elastic moduli of the rockfall and soil respectively, μ1 and μ2 are the Poisson's ratios of the rockfall and soil respectively, r1 is the radius of the rockfall, and v is the rockfall velocity.

6. The method for calculating the failure probability of a defective buried hydrogen-doped pipeline according to claim 5, characterized in that: The calculation formula of rockfall velocity v is as follows: or, Among them, h1 is the initial height of the rockfall, g is the acceleration of gravity, v0 is the initial velocity of the rockfall, f1 is the sliding friction coefficient, and b1 is the inclination angle of the slope.

7. The method for calculating the failure probability of a defective buried hydrogen-doped pipeline according to claim 1, characterized in that: When grooving is used for laying, k=0.108, K=0.235; when drilling and burying is done, k=0.096, K=0.157.

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