CN111027240B - Buried pipeline safety assessment method and related equipment - Google Patents

Abstract

The embodiment of the present invention discloses a buried pipeline safety assessment method and related equipment. After establishing the pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, the corresponding relationship between the pipeline stress influencing parameters and the pipeline stress under different working conditions is established. The training set, in which, the pipeline stress corresponding to the pipeline stress influencing parameters of different working conditions is obtained through the finite element numerical simulation method, which is more accurate and convenient than the theoretical calculation method; and because the neural network has a strong nonlinear processing ability, it can be used The training set is trained with the neural network to obtain the pipeline stress prediction model. When calculating the structural reliability of the buried pipeline according to the pipeline structure reliability calculation algorithm, the pipeline stress prediction model can be used to quickly obtain the pipeline stress, while ensuring the accuracy of the calculation results. Under the premise, the calculation time required for pipeline stress is reduced, the calculation efficiency of the structural reliability of buried pipelines is improved, and the safe operation management and technical level of buried pipelines are improved.

Description

Buried pipeline safety assessment method and related equipment

technical field

The invention relates to the technical field of pipelines, in particular to a buried pipeline safety assessment method, a buried pipeline safety assessment device, a terminal device and a computer storage medium.

Background technique

During the service process of the buried pipeline, due to the leakage of the pipe body, rain erosion, construction disturbance and other factors, part of the soil around the pipeline is hollowed out, and erosion pits are formed around the pipeline (the loss of part of the soil support of the pipeline section can also be called pipeline Under the action of overlying soil load and traffic load, a certain bending deformation or nozzle rotation will eventually lead to pipeline damage and instability. This is an irreversible and difficult to judge slow catastrophe process, which will cause huge economic losses to the society. and adverse effects. Therefore, it is urgent to solve this technical problem.

Contents of the invention

The embodiment of the present invention provides a buried pipeline safety assessment method and related equipment, which can assess the structural reliability of the buried pipeline, and further improve the safe operation management and technical level of the buried pipeline.

On the one hand, an embodiment of the present invention provides a buried pipeline safety assessment method, including:

Establish a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits;

The training set is established according to the corresponding relationship between the pipeline stress influence parameters and the pipeline stress in different working conditions, wherein, the finite element simulation analysis is carried out according to the pipeline stress influence parameters and the pipe-soil three-dimensional nonlinear finite element model, and the buried The pipeline stress of the ground pipeline, the parameters affecting the pipeline stress include erosion pit parameters;

Using the training set to carry out network training to obtain a pipeline stress prediction model;

The structural reliability of the buried pipeline is obtained according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm.

Optionally, the pipeline structure reliability calculation algorithm includes a second-order moment method, a Monte Carlo method, and a response surface method.

Optionally, the acquiring the structural reliability of the buried pipeline according to the pipeline stress prediction model and the calculation algorithm of the pipeline structure reliability includes:

Random sampling is carried out according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and N groups of sampling values about the pipeline stress influencing parameters are obtained;

Acquiring N pipeline stresses according to the sampling values and the pipeline stress prediction model;

Obtaining N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline;

Obtaining the number M of the bearable stress less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength;

The structural reliability P of the buried pipeline is calculated according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N.

Optionally, the method for determining the number of times of random sampling includes:

Obtaining a preset reliability, a preset allowable error, and a preset structural failure probability of the buried pipeline;

The number of times of random sampling is obtained according to the preset reliability, the preset allowable error, and the preset structural failure probability.

Optionally, the pipeline stress influence parameters also include more than one of pipeline parameters, soil property parameters, environmental parameters, and load parameters.

On the other hand, an embodiment of the present invention provides a buried pipeline safety assessment device, including:

A model building module, which is used to establish a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits;

The training set acquisition module is used to establish a training set according to the corresponding relationship between the pipeline stress influencing parameters and the pipeline stress in different working conditions, wherein the finite element Through simulation analysis, the pipeline stress of the buried pipeline is obtained, and the parameters affecting the pipeline stress include erosion pit parameters;

A model training module, configured to use the training set to perform network training to obtain a pipeline stress prediction model;

An evaluation module, configured to obtain the structural reliability of the buried pipeline according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm.

Optionally, the pipeline structure reliability calculation algorithm includes a second-order moment method, a Monte Carlo method, and a response surface method.

Optionally, the evaluation module includes:

The sampling sub-module is used to perform random sampling according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and obtain N groups of sampling values about the pipeline stress influencing parameters;

A stress acquisition sub-module, configured to acquire N pipeline stresses according to the sampling value and the pipeline stress prediction model;

The bearable stress acquisition sub-module is used to obtain N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline;

The number calculation sub-module is used to obtain the number M of the loadable stress less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength;

The reliability calculation sub-module is used to calculate the structural reliability P of the buried pipeline according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N.

On the other hand, an embodiment of the present invention provides a terminal device, including: a processor and a memory;

The processor is connected to a memory, wherein the memory is used to store program codes, and the processor is used to invoke the program codes to execute the buried pipeline safety assessment method.

On the other hand, an embodiment of the present invention provides a computer storage medium, the computer storage medium stores a computer program, the computer program includes program instructions, and when the program instructions are executed by a processor, execute the embedded Earth pipeline safety assessment method.

In the embodiment of the present invention, after establishing the pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, the training set is established according to the corresponding relationship between the pipeline stress influencing parameters and the pipeline stress in different working conditions, wherein, according to the pipeline stress influencing parameters and the pipeline- The 3D nonlinear finite element model of the soil is used for finite element simulation analysis to obtain the pipeline stress of the buried pipeline; and then the network training is used to obtain the pipeline stress prediction model. According to the pipeline stress prediction model and the pipeline structure reliability calculation algorithm, the buried pipeline can be obtained. The structural reliability of the pipeline; the pipeline stress in the training set data is obtained through the finite element numerical simulation method, which is more accurate and convenient than the theoretical calculation method; and because the neural network has a strong nonlinear processing capability, the training set can be used for neural network analysis. Network training to obtain the pipeline stress prediction model. When calculating the structural reliability of the buried pipeline according to the pipeline structure reliability calculation algorithm, the pipeline stress prediction model can be used to quickly obtain the pipeline stress. On the premise of ensuring the accuracy of the calculation results, reduce The calculation time required for the pipeline stress improves the calculation efficiency of the structural reliability of the buried pipeline, and then improves the safe operation management and technical level of the buried pipeline.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. Ordinary technicians can also obtain other drawings based on these drawings on the premise of not paying creative work.

Fig. 1 is a schematic flow chart of a buried pipeline safety assessment method provided by an embodiment of the present invention;

Fig. 2a, Fig. 2b and Fig. 2c are schematic diagrams of a pipe-soil three-dimensional nonlinear finite element model of a buried pipeline safety assessment method provided by an embodiment of the present invention;

Fig. 3 is a schematic flow chart of a buried pipeline safety assessment method provided by an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of a buried pipeline safety assessment device provided by an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a buried pipeline safety assessment device provided by an embodiment of the present invention;

Fig. 6 is a schematic structural diagram of a terminal device provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

It should be understood that the terms "comprising" and "having" and any variations thereof in the description, claims and drawings of the present application are intended to cover a non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally further includes For other steps or units inherent in these processes, methods, products or apparatuses.

It is known that the safety and reliability of buried pipelines cannot be evaluated in the prior art, especially for the situation where there are pipelines suspended in the air. Therefore, the method of the embodiment of the present invention is proposed to realize the evaluation of the structural reliability of buried pipelines . Specifically, please refer to FIG. 1 , which is a schematic flowchart of a buried pipeline safety assessment method provided by an embodiment of the present invention; the buried pipeline safety assessment method includes:

Step S101, establishing a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits;

Specifically, with the application of finite element technology in many fields, it can define the nonlinear parameters of materials for structural static calculation, contact calculation, stress-strain calculation, etc.; when solving problems, different load steps and convergence criteria can be defined , which provides great convenience for the solution of the nonlinear finite element, therefore, the embodiment of the present invention builds the finite element model of the buried pipeline; and in order to reflect the impact of the erosion pit on the performance of the buried pipeline, when establishing the model, it is necessary Introduce erosion pits to establish a virtual model of buried pipelines and soil, that is, a pipe-soil three-dimensional nonlinear finite element model with erosion pits, refer to Figure 2a, Figure 2b, and Figure 2c, and Figure 2a, Figure 2b, and Figure 2c are A schematic diagram of a pipe-soil three-dimensional nonlinear finite element model of a buried pipeline safety assessment method provided by an embodiment of the present invention, wherein the buried pipeline 22 is inside the soil 21, and the erosion pit 23 is generally located at the lower part of the buried pipeline 22 .

Step S102, establish a training set according to the corresponding relationship between pipeline stress influencing parameters and pipeline stress in different working conditions, wherein, perform finite element simulation analysis according to the pipeline stress influencing parameters and the pipe-soil three-dimensional nonlinear finite element model, and obtain The pipeline stress of the buried pipeline, the pipeline stress influencing parameters include erosion pit parameters;

Specifically, the pipeline stress influence parameter refers to a parameter that has influence on the stress of the buried pipeline, and may be a single pipeline stress influence parameter or multiple different pipeline stress influence parameters. Modify the parameters of the pipe-soil three-dimensional nonlinear finite element model according to the influence parameters of pipeline stress in different working conditions, and then perform simulation analysis on the pipe-soil nonlinear three-dimensional finite element model after parameter modification to obtain the pipeline stress of the buried pipeline; by changing the pipeline The specific values of the stress-influencing parameters and the simulation of different working conditions of the buried pipeline can obtain the pipeline stress corresponding to different working conditions. Finally, the training set is established according to the corresponding relationship between the pipeline stress-influencing parameters and the pipeline stress in different working conditions.

Step S103, using the training set to perform network training to obtain a pipeline stress prediction model;

Specifically, the neural network is trained according to the obtained training set to obtain a well-trained pipeline stress prediction model.

Step S104, obtaining the structural reliability of the buried pipeline according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm.

Specifically, structural reliability refers to the probability of completing a predetermined function within a specified time and under specified conditions.

From the above, it can be seen that the pipeline stress in the training set data is obtained by the finite element numerical simulation method, which is more accurate and convenient than the theoretical calculation method; because there is a nonlinear correlation between the pipeline stress influencing parameters and the pipeline stress, and the neural network With a high degree of non-linear mapping capability, the pipeline stress prediction model that can predict pipeline stress can be obtained by using the training set obtained by finite element technology for model training, which can be used to approximately replace the original finite element simulation analysis and effectively save the stress on buried pipelines Analysis time; when calculating the structural reliability of buried pipelines according to the pipeline structure reliability calculation algorithm, the pipeline stress prediction model can be used to quickly obtain the pipeline stress, and reduce the calculation required for the pipeline stress on the premise of ensuring the accuracy of the calculation results It improves the calculation efficiency of the structural reliability of buried pipelines, and then improves the safe operation management and technical level of buried pipelines.

Further, in addition to erosion pit parameters, the pipeline stress influence parameters also include more than one of pipeline parameters, soil property parameters, environmental parameters, and load parameters. Referring to Fig. 2b and Fig. 2c, the erosion pit parameters include the axial length Vd, the lateral depth Vl, and the circumferential angle θ of the erosion pit 23; the pipeline parameters refer to various specific parameters of buried pipelines, including pipeline material types (pipe material types, such as PVC-polyvinyl chloride pipe, DI-cast iron pipe), pipe outer diameter, wall thickness, pipe length, elastic modulus, ultimate strength, Poisson's ratio, expansion coefficient, etc.; and soil property parameters include soil type (such as protoplasm soil, backfill), soil density, elastic modulus, Poisson's ratio, friction angle, cohesion, etc.; while environmental parameters include buried pipeline depth, temperature, pipeline internal pressure, etc.; load parameters include ground traffic load , frost heave load, etc.

The concrete realization process of described step S101, step S102 is described in detail below:

Step S101, establishing a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits;

Specifically, according to the structural design of the buried pipeline and the actual construction drawings, use the ABAQUS finite element software (also FLAC3D, ANSYS and other finite element software), and comprehensively consider the specific conditions (the conditions of the buried pipeline to be evaluated) The deformation characteristics of the soil, the elastic-plastic constant of the soil, the tangential friction between the pipe and the soil, the stiffness of the pipe itself when the force is applied, and the response of the surrounding soil when the pipe undergoes structural deformation, adopt the finite element analysis method of the pipe-soil nonlinear contact , according to the length, cross-section, density, Poisson's ratio, elastic modulus of the buried pipeline and the density, Poisson's ratio, elastic modulus, friction angle, and cohesion of the soil, a preliminary pipe-soil three-dimensional nonlinear finite Meta-model; referring to the installation method of pipeline embankment filling in the actual construction project, five analysis steps are established in the model to simulate the construction process in stages. According to the stress design requirements of the pipeline, the corrosion pit existing around the pipeline is introduced by the life-death unit technology, and the size of the erosion pit is defined, including the axial length, lateral depth, and circumferential angle of the erosion pit, and finally the establishment of the erosion pit with the erosion pit is completed. Pipe-soil three-dimensional nonlinear finite element model, the size data of the erosion pit defined here can be the size data of the virtual erosion pit, or the size data of the erosion pit obtained by real measurement.

From the above, it can be seen that the pipe-soil three-dimensional nonlinear finite element model with erosion pits is established according to the pipe stress influence parameters of buried pipes.

Step S102, establish a training set according to the corresponding relationship between pipeline stress influencing parameters and pipeline stress in different working conditions, wherein, perform finite element simulation analysis according to the pipeline stress influencing parameters and the pipe-soil three-dimensional nonlinear finite element model, and obtain The pipeline stress of the buried pipeline, the pipeline stress influencing parameters include erosion pit parameters;

Specifically, in order to simulate different working conditions of buried pipelines, the control variable method is used to generate multiple sets of different pipeline stress influence parameters. Different sets of pipeline stress influence parameters, the number of parameters in the pipeline stress influence parameters is the same as that of the pipeline stress influence parameters used in the original model building, for example, suppose the pipeline stress influence parameters include erosion pit parameters, pipeline parameters, soil mass There are five types of characteristic parameters, environmental parameters, and load parameters, you can modify the value of one of the five parameters, or modify the value of two of the five parameters, or modify three of the five parameters, so as to By analogy, the influence parameters of pipeline stress in various working conditions can be obtained. The parameters in the original model are replaced by the pipeline stress influencing parameters of different working conditions, and the pipeline stress of the buried pipeline can be obtained by using the finite element analysis software. The pipeline stress includes longitudinal stress, hoop stress and radial stress. Finally, a database is established according to the corresponding relationship between pipeline stress influencing parameters and pipeline stress in different working conditions. Among them, the pipeline stress influencing parameters of a working condition correspond to a pipeline stress, and the database is used as the training set of the neural network.

It can be seen from the above that due to the powerful modeling function of finite element software, convenient modeling, and more accurate than theoretical calculation, the pipeline stress in the training set data obtained by finite element numerical simulation is more accurate than theoretical calculation. convenient.

Taking the longitudinal stress of the pipeline as an example, the calculation process of the longitudinal stress of the pipeline is illustrated by modifying the values of the three parameters: pipeline parameters, environmental parameters and load parameters:

When the soil support under the buried pipeline is lost and the pipeline is partially suspended, the pipeline under the action of the erosion pit is approximately regarded as a partially suspended beam, and certain bending deformation occurs under the upper load. Under the action of erosion pit, the pipeline produces longitudinal stress, hoop stress and radial stress under various loads. The longitudinal stress of the pipeline is the sum of the longitudinal stress caused by the horizontal tension and the longitudinal stress caused by the internal pressure of the pipeline, uniform load and temperature difference. The calculation formula of the longitudinal stress of the pipeline is:

In the formula, D is the outer diameter of the pipe, t is the wall thickness of the pipe, P is the internal pressure of the pipe, M(x) is the bending moment of the pipe section, W is the bending section coefficient of the pipe, N is the horizontal tensile force of the pipe, and S is the pipe wall Cross-sectional area, E is the elastic modulus of the pipe, and Δt is the temperature difference.

Further, the specific implementation process of step S103 is:

The neural network is trained according to the training set to establish a neural network that can correctly map the input (pipeline stress influencing parameters) and output (pipeline stress), that is, the pipeline stress prediction model. In the embodiment of the present invention, the pipeline stress is simulating the pipeline longitudinal stress as an example, and the pipeline stress prediction model predicts the pipeline longitudinal stress.

Further, in step S104, the pipeline structure reliability calculation algorithm includes a second-order moment method, a Monte Carlo method, and a response surface method. The first second moment method is a reliability analysis method to calculate the structural reliability based on the mean value and variance of variables. The basic principle of the Monte Carlo method is a reliability analysis and design method that uses random sampling for reliability calculation statistics, so the Monte Carlo method is also called random sampling method. The response surface method is based on statistics, and can be used to solve the relationship between the random input and the random response of the system. Sometimes the random input and random output function relationship of the structure is not easy to obtain. At this time, the response surface can be used. approach to approximate simulation. The specific theoretical guidance of the response surface method is to use a limited number of experiments, construct a polynomial with a clear expression form to approximate the structure-function function that cannot be expressed by an explicit function, and in an explicit form, and then use the Jc method (equivalent normalization method) to calculate the reliability of the structure, this calculation method can greatly improve the calculation efficiency.

When the calculation algorithm for the reliability of the pipeline structure is the Monte Carlo method, it is necessary to first establish the limit state equation of the pipeline, that is, the calculation equation of the loadable stress of the buried pipeline. After determining the ultimate strength of buried pipelines, for pipelines subjected to various loads under the influence of erosion pits, the safety factor is an important indicator for judging whether the pipeline is reliable or not. When the stress of the pipeline exceeds the ultimate strength of the pipeline, it is determined that the pipeline fails , the embodiment of the present invention takes the longitudinal stress of the pipeline as an example, and when the longitudinal stress of the pipeline exceeds the ultimate strength of the pipeline, it is determined that the pipeline fails. Let X ₁ , X ₂ ,..., X _n be n random variables that affect the structural reliability of the pipeline (namely, parameters affecting pipeline stress), for example, random variables X ₁ , X ₂ , ..., X _n are the geometric dimensions of the pipeline, soil Body characteristic parameters, external environmental factors, etc. According to the ultimate strength theory, the limit state function of the pipeline under the action of erosion pits can be expressed as:

Z=σ _s -σ(X ₁ ,X ₂ ,…X _n ),

Where: σ _s is the ultimate strength of the pipeline, and σ(X ₁ ,X ₂ ,…X _n ) is the longitudinal stress of the pipeline under the action of random variables.

When Z>0, the structure of the buried pipeline has the specified function, that is, it is in a reliable state;

When Z<0, the structure of the buried pipeline loses its specified function, that is, it is in a failure state;

When Z=0, the structure of the buried pipeline is in a critical state or called a limit state.

Continuing to refer to FIG. 3, FIG. 3 is a schematic flowchart of a buried pipeline safety assessment method provided by an embodiment of the present invention, and the step S104 includes:

Step S301, performing random sampling according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and obtaining N groups of sampling values about the pipeline stress influencing parameters;

Specifically, the probability distribution of pipeline stress influencing parameters includes uniform distribution and normal distribution, and N times random sampling is performed according to the probability distribution of pipeline stress influencing parameters to obtain N groups of specific values about pipeline stress influencing parameters.

Step S302, obtaining N pipeline stresses according to the sampled values and the pipeline stress prediction model;

Specifically, N pipeline stresses can be obtained by inputting the sampled values into the pipeline stress prediction model. Here, the N pipeline longitudinal stresses are obtained as an example.

Step S303, obtaining N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline;

Specifically, N loadable stresses can be obtained according to the N pipeline stresses and the pipeline limit state equation, and N Z can be obtained when the pipeline stress is the pipeline longitudinal stress.

Step S304, obtaining the number M of the loadable stresses less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength;

Specifically, the preset value can be adjusted according to the evaluation requirements for the reliability of the pipeline structure, and can be set to any value between the ultimate strength and 0. The preset value of the embodiment of the present invention is 0 as an example, and the obtained loadable stress is less than or equal to The number M of 0, that is, to obtain the number of Z less than or equal to 0.

Step S305, calculating the structural reliability P of the buried pipeline according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N.

Specifically, M/N is the failure probability of buried pipelines, that is, the possibility of failure of buried pipelines, and the structural reliability P of buried pipelines is 1-M/N. According to P, the structural reliability of buried pipelines can be evaluated In order to improve the safety management and operation level of buried pipelines.

Wherein, the determination method of the number of times N of described random sampling comprises:

Step A1, obtaining a preset reliability, a preset allowable error, and a preset structural failure probability of the buried pipeline;

Specifically, the specific values of the preset reliability and the preset allowable error can be set according to needs, and the preset structural failure probability of the buried pipeline is the pre-estimated structural failure probability of the buried pipeline, which is generally relatively small.

Step A2, obtaining the number of times of random sampling according to the preset reliability, the preset allowable error, and the preset structural failure probability.

Specifically, taking the preset confidence level of 95% as an example, after setting the preset allowable error, the calculation formula of the error ε is:

Among them, P _f is the failure probability of the preset structure, and N is the number of random sampling, so the larger N is, the smaller the error ε is. It can be seen that the number of random sampling is related to the calculation accuracy of the final structural reliability, and only when the Monte Carlo When the number of Luo simulations is large enough, the accuracy of the structural failure probability tends to be stable, that is, the accuracy of the structural reliability tends to be stable. N needs to satisfy the following formula:

N≥100/P _f ,

Assuming that the failure probability of the preset structure is below 0.1%, the number of random sampling must reach more than 100,000 times.

For the process of calculating the reliability of the pipeline structure by using the first-order second-order moment method and the response surface method, reference can be made to the calculation process in the prior art, and details will not be repeated here.

The following is an example of water supply pipes (including PVC and DI pipes, taking PVC pipes as an example) to illustrate the calculation process of the reliability of the entire structure:

Step S1, establish the pipe-soil three-dimensional nonlinear finite element model according to the parameters affecting the pipe stress in Table 1. Taking the pipe longitudinal stress as an example, there are many parameters affecting the pipe longitudinal stress. In this example, the pipe diameter, wall thickness, The effects of burial depth, pipeline internal pressure, soil properties, and erosion pit size on the longitudinal stress of the pipeline. The finite element software can calculate the longitudinal stress of the pipeline by using these influencing parameters.

Table 1

Step S2, modifying the specific values of the above-mentioned influencing parameters to obtain the influencing parameters of the pipeline stress for simulating different working conditions, and using the finite element analysis software to obtain the corresponding pipeline longitudinal stress.

Step S3, since there is a nonlinear implicit relationship between the influencing parameters and the longitudinal stress of the pipeline, the neural network is used to train the data of the finite element simulation analysis (the influencing parameters of the pipeline stress under different working conditions and the corresponding longitudinal stress of the pipeline) to obtain the pipeline stress predictive model.

Step S4, consulting the data to determine the ultimate strength of the PVC pipe. Establish the pipeline limit state equation (safety margin expression).

Step S5, according to the main parameters affecting the longitudinal stress of the pipeline, such as pipe diameter, wall thickness, buried depth, soil elastic modulus, internal pressure of the pipeline, and length of the erosion pit, determine the probability distribution of each parameter, as shown in Table 2. According to the probability distribution of each parameter, the random sampling method is used to conduct 10 ⁵ samples to obtain the corresponding data of 10 ⁵ ×6, which are substituted into the pipeline stress prediction model to obtain 10 ⁵ limit function values Z.

Table 2

Step S6, according to the law of large numbers, calculate the structural reliability of the pipeline, and finally calculate the structural reliability of the pipeline to be 0.963.

Based on the description of the embodiment of the buried pipeline safety assessment method above, the embodiment of the present invention also discloses a buried pipeline safety assessment device, referring to Fig. 4, which is a buried pipeline safety assessment device provided by the embodiment of the present invention The structural schematic diagram of the buried pipeline safety assessment device includes a model building module 401, a training set acquisition module 402, a model training module 403, and an evaluation module 404; wherein:

The model building module 401 is used to establish a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits;

The training set acquisition module 402 is used to establish a training set according to the corresponding relationship between pipeline stress influencing parameters and pipeline stress in different working conditions, wherein the limited The element simulation analysis obtains the pipeline stress of the buried pipeline, and the parameters affecting the pipeline stress include erosion pit parameters;

A model training module 403, configured to use the training set to perform network training to obtain a pipeline stress prediction model;

The evaluation module 404 is configured to obtain the structural reliability of the buried pipeline according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm.

For the implementation of specific functions of the model building module 401 , the training set acquisition module 402 , the model training module 403 , and the evaluation module 404 , refer to steps S101 - S104 in the above-mentioned embodiments, and will not be repeated here.

Further, the simulated pipeline stress influence parameters also include more than one of pipeline parameters, soil property parameters, environmental parameters, and load parameters. The pipeline structure reliability calculation algorithm includes a second-order moment method, a Monte Carlo method, and a response surface method.

Further, referring to FIG. 5, FIG. 5 is a schematic structural diagram of a buried pipeline safety evaluation device provided by an embodiment of the present invention; the evaluation module 404 includes a sampling sub-module 501, a stress acquisition sub-module 502, a loadable stress acquisition sub-module Module 503, number calculation sub-module 504, reliability calculation sub-module 505, wherein:

The sampling sub-module 501 is used to perform random sampling according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and obtain N groups of sampling values about the pipeline stress influencing parameters;

A stress acquisition sub-module 502, configured to acquire N pipeline stresses according to the sampling value and the pipeline stress prediction model;

The bearable stress acquisition sub-module 503 is used to obtain N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline;

The number calculation sub-module 504 is used to obtain the number M of the loadable stress less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength;

The reliability calculation sub-module 505 is used to calculate the structural reliability P of the buried pipeline according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N.

Among them, the specific function implementation of the sampling sub-module 501, the stress acquisition sub-module 502, the loadable stress acquisition sub-module 503, the number calculation sub-module 504, and the reliability calculation sub-module 505 can refer to step S301-step in the above-mentioned embodiment S305, which will not be repeated here.

Further, the device also includes a sampling number determination module, and the sampling number determination module includes:

The preset value acquisition sub-module is used to acquire the preset reliability, the preset allowable error and the preset structural failure probability of the buried pipeline;

The times calculation sub-module is used to obtain the times of random sampling according to the preset reliability, the preset allowable error, and the preset structural failure probability.

Wherein, the specific function implementation manners of the preset value acquisition sub-module and the times calculation sub-module can refer to step A1-step A2 in the above embodiment, and will not be repeated here.

It is worth pointing out that each unit or module in the buried pipeline safety assessment device shown in Fig. 4 and Fig. 5 can be respectively or all combined into one or several other units or modules to form, or one of them (some ) units or modules can also be further divided into functionally smaller units or modules, which can achieve the same operation without affecting the realization of the technical effects of the embodiments of the present invention. The above-mentioned units or modules are divided based on logical functions. In practical applications, the functions of one unit (or module) can also be realized by multiple units (or modules), or the functions of multiple units (or modules) can be realized by one unit (or module) implementation.

Based on the descriptions of the foregoing method embodiments and apparatus embodiments, embodiments of the present invention further provide a terminal device.

Please refer to FIG. 6 , which is a schematic structural diagram of a terminal device provided by an embodiment of the present invention. As shown in FIG. 6, the buried pipeline safety assessment apparatus in the above-mentioned FIGS. The terminal device 600 may further include: a user interface 603 and at least one communication bus 602 . Wherein, the communication bus 602 is used to realize connection and communication between these components. Wherein, the user interface 603 may include a display screen (Display) and a keyboard (Keyboard), and the optional user interface 603 may also include a standard wired interface and a wireless interface. Optionally, the network interface 604 may include a standard wired interface and a wireless interface (such as a WI-FI interface). The memory 605 may be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one disk memory. Optionally, the memory 605 may also be at least one storage device located away from the aforementioned processor 601 . As shown in FIG. 6 , the memory 605 as a computer storage medium may include an operating system, a network communication module, a user interface module, and a device control application program.

In the terminal device 600 shown in FIG. 6 , the network interface 604 can provide a network communication function; the user interface 603 is mainly used to provide an input interface for the user; and the processor 601 can be used to call the device control application stored in the memory 605 program to achieve:

Establish a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits;

The training set is established according to the corresponding relationship between the pipeline stress influence parameters and the pipeline stress in different working conditions, wherein, the finite element simulation analysis is carried out according to the pipeline stress influence parameters and the pipe-soil three-dimensional nonlinear finite element model, and the buried The pipeline stress of the ground pipeline, the parameters affecting the pipeline stress include erosion pit parameters;

Using the training set to carry out network training to obtain a pipeline stress prediction model;

The structural reliability of the buried pipeline is obtained according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm.

In one embodiment, the simulated pipe stress influence parameters further include more than one of pipe parameters, soil property parameters, environment parameters, and load parameters. The pipeline structure reliability calculation algorithm includes a second-order moment method, a Monte Carlo method, and a response surface method.

In one embodiment, when the processor 601 executes the acquisition of the structural reliability of the buried pipeline according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm, the following steps are specifically performed:

Random sampling is carried out according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and N groups of sampling values about the pipeline stress influencing parameters are obtained;

Acquiring N pipeline stresses according to the sampling values and the pipeline stress prediction model;

Obtaining N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline;

Obtaining the number M of the bearable stress less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength;

The structural reliability P of the buried pipeline is calculated according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N.

In one embodiment, the processor 601 is further configured to perform the following steps:

Obtaining a preset reliability, a preset allowable error, and a preset structural failure probability of the buried pipeline;

The number of times of random sampling is obtained according to the preset reliability, the preset allowable error, and the preset structural failure probability.

It should be understood that the terminal device 600 described in the embodiment of the present invention can execute the description of the safety assessment method for buried pipelines in the embodiments corresponding to FIGS. The description of the buried pipeline safety assessment device in the embodiments will not be repeated here. In addition, the description of the beneficial effect of adopting the same method will not be repeated here.

In addition, it should be pointed out here that the embodiment of the present invention also provides a computer storage medium, and the computer storage medium stores the computer program executed by the above-mentioned buried pipeline safety assessment device, and the computer The program includes program instructions. When the processor executes the program instructions, it can execute the description of the buried pipeline safety assessment method in the embodiments corresponding to FIGS. 1 to 3 above, so details will not be repeated here. . In addition, the description of the beneficial effect of adopting the same method will not be repeated here. For the technical details not disclosed in the embodiments of the computer storage medium involved in the present invention, please refer to the description of the method embodiments of the present invention.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented through computer programs to instruct related hardware, and the programs can be stored in a computer-readable storage medium. During execution, it may include the processes of the embodiments of the above-mentioned methods. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM) or a random access memory (Random AccessMemory, RAM), etc.

The above disclosures are only preferred embodiments of the present invention, and certainly cannot limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims (10)

1. A buried pipeline safety assessment method, characterized in that, comprising: Establish a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits; The training set is established according to the corresponding relationship between the pipeline stress influence parameters and the pipeline stress in different working conditions, wherein, the finite element simulation analysis is carried out according to the pipeline stress influence parameters and the pipe-soil three-dimensional nonlinear finite element model, and the buried The pipeline stress of the ground pipeline, the parameters affecting the pipeline stress include erosion pit parameters; Using the training set to carry out network training to obtain a pipeline stress prediction model; The structural reliability of the buried pipeline is obtained according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm. 2. The method according to claim 1, wherein the calculation algorithm for the reliability of the pipeline structure includes a first-order second-order moment method, a Monte Carlo method, and a response surface method. 3. The method according to claim 1 or 2, wherein said obtaining the structural reliability of said buried pipeline according to said pipeline stress prediction model and pipeline structural reliability calculation algorithm comprises: Random sampling is carried out according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and N groups of sampling values about the pipeline stress influencing parameters are obtained; Acquiring N pipeline stresses according to the sampling values and the pipeline stress prediction model; Obtaining N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline; Obtaining the number M of the bearable stress less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength; The structural reliability P of the buried pipeline is calculated according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N. 4. method according to claim 3, is characterized in that, the determining method of the number of times of described random sampling comprises: Obtaining a preset reliability, a preset allowable error, and a preset structural failure probability of the buried pipeline; The number of times of random sampling is obtained according to the preset reliability, the preset allowable error, and the preset structural failure probability. 5. The method according to claim 1 or 2, wherein the pipeline stress influencing parameters further include more than one of pipeline parameters, soil property parameters, environmental parameters, and load parameters. 6. A buried pipeline safety assessment device, characterized in that it comprises: A model building module, which is used to establish a pipe-soil three-dimensional nonlinear finite element model of the buried pipeline, and the pipe-soil three-dimensional nonlinear finite element model includes erosion pits; The training set acquisition module is used to establish a training set according to the corresponding relationship between the pipeline stress influencing parameters and the pipeline stress in different working conditions, wherein the finite element Through simulation analysis, the pipeline stress of the buried pipeline is obtained, and the parameters affecting the pipeline stress include erosion pit parameters; A model training module, configured to use the training set to perform network training to obtain a pipeline stress prediction model; An evaluation module, configured to obtain the structural reliability of the buried pipeline according to the pipeline stress prediction model and the pipeline structural reliability calculation algorithm. 7. The device according to claim 6, wherein the calculation algorithm for the reliability of the pipeline structure includes a first-order second-order moment method, a Monte Carlo method, and a response surface method. 8. The device according to claim 6 or 7, wherein the evaluation module comprises: The sampling sub-module is used to perform random sampling according to the probability distribution of the pipeline stress influencing parameters of the buried pipeline, the number of random sampling is N, and obtain N groups of sampling values about the pipeline stress influencing parameters; A stress acquisition sub-module, configured to acquire N pipeline stresses according to the sampling value and the pipeline stress prediction model; The bearable stress acquisition sub-module is used to obtain N bearable stresses according to the difference between the ultimate strength of the buried pipeline and the stress of the pipeline; The number calculation sub-module is used to obtain the number M of the loadable stress less than or equal to a preset value, and the preset value is smaller than the value of the ultimate strength; The reliability calculation sub-module is used to calculate the structural reliability P of the buried pipeline according to the N and the number M, and the calculation formula of the structural reliability P is P=1-M/N. 9. A terminal device, comprising: a processor and a memory; The processor is connected to a memory, wherein the memory is used to store program codes, and the processor is used to call the program codes to execute the buried pipeline safety assessment method according to any one of claims 1-5 . 10. A computer storage medium, characterized in that the computer storage medium stores a computer program, the computer program includes program instructions, and when the program instructions are executed by a processor, perform any one of claims 1-5. The buried pipeline safety assessment method described in the item.

Images