CN114636496B - Method for monitoring and early warning stress of buried pipeline of natural gas station under foundation settlement effect - Google Patents
Method for monitoring and early warning stress of buried pipeline of natural gas station under foundation settlement effect Download PDFInfo
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- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0047—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes measuring forces due to residual stresses
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Abstract
The invention provides a stress monitoring and early warning method for buried pipelines of a natural gas station under the action of foundation settlement, which is characterized in that the stress distribution condition of the buried pipelines of the station is determined through finite element simulation, the stress monitoring and foundation settlement monitoring are implemented on the pipeline sections with higher stress level by combining engineering experience, the collected data are transmitted to a control room terminal through a signal base station, long-term real-time monitoring is realized, data processing is carried out, pipeline stress, pipeline working internal pressure and foundation settlement regression expression are established, foundation settlement data are predicted through a gray prediction model, the stress state of the pipelines is further predicted, and finally, the result can be visualized through a program, so that a pipeline manager can conveniently and timely process, the pipeline safety is ensured, long-period continuous real-time monitoring can be realized, and the monitoring integrity is ensured.
Description
Technical Field
The invention belongs to the technical field of safety operation monitoring and early warning of natural gas pipelines, and particularly relates to a method for monitoring and early warning the safety state of a buried pipeline under the effect of non-uniform settlement of a foundation.
Background
Natural gas stations in coastal areas of China are mostly built on coastal areas, lakeside areas, river coastal areas and the like, geological conditions are mostly soft soil foundations with low strength and higher compressibility, uneven settlement is easy to generate due to rheological property and non-uniformity, and site movement caused by the uneven settlement often causes additional stress and deformation of buried natural gas pipelines, and disasters are caused when serious.
The method for monitoring the structural integrity and stress state of the natural gas pipeline is more, wherein the resistance strain method is the most common pipeline stress monitoring method due to low cost, high measurement precision and wide application range. The resistance strain gauge is stuck on the pipeline, the pipeline generates strain under the load of external force, and the strain can be transmitted to the resistance strain gauge to cause the change of the resistance strain gauge.
At present, as Zhihao and the like provide in the Chinese published invention patent CN112924061A for a wireless real-time monitoring system and method for non-uniform settlement stress of a natural gas pipeline, the main steps for monitoring the safety state of a buried natural gas pipeline by adopting a stress strain monitoring technology are as follows: (1) determining the position of the high-risk pipe section according to engineering experience; (2) excavating soil filled above the monitoring pipe section, treating the surface of the cleaning pipe section, arranging strain gauges, generally arranging along the axial direction and the circumferential direction of the pipeline, connecting wires and sealing the strain gauges; (3) and after backfilling earthwork, connecting a strain data acquisition system, and periodically monitoring after balance adjustment of the initial state of the system to obtain the stress state of the pipeline. From the above, the prior art has the following drawbacks:
1. the monitoring points are blind. The high risk area of the pipeline is determined, the scientific basis is lacked according to engineering experience generally, and hidden danger pipe sections are easily ignored.
2. The periodic monitoring can only reflect the stress state of the pipeline in a certain time period, the stress change of the pipeline in the whole process cannot be provided, and the stress abrupt change node is easy to ignore, so that the pipeline hidden danger can be discovered timely by pipeline management staff.
3. The monitoring data and the processing are too single, the influence caused by the pipeline working pressure is ignored, and the pipeline sedimentation stress cannot be distinguished.
4. The monitoring data lacks of subsequent processing, only can master the current state, the subsequent change cannot be predicted, and the change cannot be mastered in advance.
Disclosure of Invention
According to the method for monitoring and early warning the stress of the buried pipeline of the natural gas station under the foundation settlement effect, the key position of the pipeline for carrying out stress monitoring can be determined, the effective real-time monitoring can be carried out, meanwhile, the stress change trend of the pipeline can be predicted, and the safe operation of the pipeline is ensured.
In order to achieve the purpose of the invention, the method for monitoring and early warning the stress of the buried pipeline of the natural gas station under the foundation settlement effect comprises the following steps:
drawing a three-dimensional model of the buried pipeline, introducing the three-dimensional model into finite element analysis software, determining a finite element constitutive equation, establishing a finite element model, performing finite element numerical simulation to obtain a stress cloud picture, determining a pipe section with larger stress of the buried pipeline through the stress cloud picture, and determining a pipe section needing stress monitoring;
arranging a double-shaft strain gage on a pipe section needing to be subjected to stress monitoring, wherein the double-shaft strain gage is used for monitoring additional circumferential and axial strain of the pipe section caused by foundation settlement;
setting a settlement monitoring device on the surface of the monitoring pipe section, and carrying out pipeline additional strain monitoring and foundation settlement monitoring to obtain additional circumferential and axial strain data and foundation settlement data;
outputting the monitored additional circumferential and axial strain data into the pipeline additional circumferential stress and the pipeline additional axial stress through a stress-strain formula;
the monitoring data is transmitted to a central control room of the natural gas station through the wireless data transmission device and the signal base station, so that real-time online monitoring is realized;
checking and calculating the current Von-Mises equivalent stress of the pipeline according to the Von-Mises yield criterion;
constructing a polynomial mathematical expression of the pipeline Von-Mises stress, the pipeline working internal pressure and the foundation settlement by using the pipeline Von-Mises stress value, the pipeline working internal pressure and the foundation settlement, and fitting a regression expression of the pipeline stress, the pipeline working internal pressure and the foundation settlement by polynomial regression;
and predicting future foundation settlement according to the monitored foundation settlement data by using a gray prediction model method, substituting the foundation settlement prediction value and the pipeline working internal pressure into a regression expression, and predicting the equivalent stress of the pipeline Von-Mises under the future settlement condition.
Further, a pipeline stress risk rating is established to evaluate the current pipeline stress level, wherein the pipeline stress risk rating comprises grading the stress level of the whole pipeline through Von-Mises equivalent stress, and evaluating the settlement additional stress by adopting the maximum value of the pipeline circumferential additional stress and the axial additional stress obtained in stress monitoring, so as to obtain the risk rating.
Further, the method can also realize data visualization through program codes, and output monitoring data, calculation data, prediction data and pipeline risk level through a computer program window.
Furthermore, the buried soil information of the natural gas station is required to be collected before the three-dimensional model of the buried pipeline is drawn, and the physical parameters of the pipeline and the buried soil physical parameters are acquired.
Further, the physical parameters of the pipeline comprise pipe diameter, pipe thickness, density, poisson ratio and tensile strength, and the physical parameters of the buried soil comprise uniaxial tensile strength, triaxial tensile strength, density, internal friction angle and cohesive force.
Further, the stress-strain formula is:
in sigma hc Adding stress to the circumferential direction of the measured pipeline; sigma (sigma) zc Axially adding stress to the measured pipeline; e is the elastic modulus of the pipeline; μ is poisson's ratio of the pipeline; epsilon h Circumferential strain for the measured pipe; epsilon z Is the measured axial strain of the pipe.
Further, if a pressure regulating process occurs in the pipeline operation, the internal pressure of the pipeline is changed to cause the stress change of the pipeline, and the stress-strain formula is as follows:
in sigma hc Adding stress to the circumferential direction of the measured pipeline; sigma (sigma) h The pipeline circumferential additional stress caused by foundation settlement is applied; sigma (sigma) zc To add stress, sigma, to the measured pipe axis z Additional stress is axially added to the pipeline caused by foundation settlement; Δp is the internal pressure change value of the pipeline, the pressure rise is positive, and D is the external diameter of the pipeline; delta is the wall thickness of the pipeline.
Further, the calculation formula of Von-Mises equivalent stress is:
in the method, in the process of the invention,
representing the Von-Mises equivalent stress of the pipeline and MPa; sigma (sigma) H 、σ Z 、σ J The principal stresses in the axial, annular and radial directions are indicated.
Further, since the pipe satisfies the thin-wall feature, the radial principal stress σ J Far less than the stresses in the other two directions, negligible, 0, and axial principal stress sigma H And principal stress sigma in the circumferential direction Z The calculation formula of (2) is as follows:
σ H ＝σ h +σ pH
σ Z ＝σ z +σ pZ
in the method, in the process of the invention,
wherein sigma pH Is the hoop stress of the pipeline caused by the internal pressure; sigma (sigma) pZ The axial stress of the pipeline caused by the internal pressure is the working internal pressure of the pipeline; d is the outer diameter of the pipeline; delta is the wall thickness of the pipeline.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention determines the stress condition of the buried pipeline under the foundation settlement effect through simulation and combines engineering experience, thereby accurately arranging the stress monitoring pipeline section.
2. The invention transmits the monitoring data to the terminal through the wireless transmission technology, can realize continuous real-time monitoring in a long period and ensures the monitoring integrity.
3. According to the invention, the wireless device is added to connect the monitoring system with the processing terminal, so that long-time real-time monitoring is realized, and the monitoring empty period in periodic monitoring is filled.
4. The invention establishes a pipeline risk matrix, which comprises pipeline stress risk levels caused by foundation settlement on one hand and pipeline total stress risk levels on the other hand. By establishing the pipeline risk matrix, the main factors influencing the stress of the pipeline can be judged so as to take corresponding countermeasure measures.
5. The invention can also provide data visualization processing, and data such as stress monitoring data, sedimentation data change trend, pipeline stress level, predicted pipeline future stress change and the like are output by programming.
Drawings
Fig. 1 is a flowchart of steps of a method according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of the invention at the point of measurement of strain gauge in a pipe arrangement.
FIG. 3 is a schematic diagram of an embodiment of the present invention.
FIG. 4 is a schematic diagram showing the analysis of the correlation between the pipeline stress and the pipeline working internal pressure and the foundation settlement according to the invention.
FIG. 5 is a graph showing stress monitoring curves of various measuring points obtained in the examples of the present invention.
Fig. 6 is a schematic diagram of foundation settlement data obtained by monitoring in the embodiment of the present invention.
FIG. 7 is a schematic illustration of Von-Mises stress curves for various stations obtained in an example of the present invention.
FIG. 8 is a diagram showing the results of the present invention in data visualization.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
As shown in fig. 1 to 5, the method for monitoring and early warning the stress of the buried pipeline of the natural gas station under the foundation settlement effect comprises the following steps:
and step 1, collecting and consulting natural gas pipeline data of the natural gas station according to a natural gas station design drawing and a construction scheme, wherein the natural gas pipeline data comprises pipeline size parameters and physical parameters related to soil burying.
In some embodiments of the invention, the pipe dimension parameters include pipe strike, pipe burial depth, and pipe physical parameters (pipe diameter, pipe thickness, density, poisson's ratio, tensile strength, etc.), and the yard burial soil related physical parameters include uniaxial tensile strength, triaxial tensile strength, density, internal friction angle, cohesion, etc.
And 2, drawing a three-dimensional model of the buried pipeline, importing the three-dimensional model of the buried pipeline into finite element analysis software, determining a finite element constitutive equation, establishing a finite element model, including a buried finite element model and a pipeline finite element model, setting physical parameters of pipeline materials, simulating the stress state of the pipeline under the foundation settlement effect through the finite element analysis software, outputting a stress cloud picture, determining a pipeline section with larger stress of the buried pipeline based on the stress cloud picture, and carrying out stress monitoring in a larger area of the buried pipeline section by combining engineering experience.
In some embodiments of the invention, after determining a pipe section with larger stress according to the stress cloud chart, the pipe section needing stress monitoring is selected by combining engineering experience (such as an elbow, a tee joint, the vicinity of a welding line and the like).
In some embodiments of the invention, the finite element analysis software is ANSYS software.
In some embodiments of the invention, the constitutive equation selected when the buried finite element model is built is a Dracker-Prager constitutive equation, and the constitutive equation selected when the pipeline finite element model is built is a Ramberg-Osgood constitutive equation.
And 3, digging buried soil, arranging a double-shaft strain gauge on a pipe section needing stress monitoring, wherein the double-shaft strain gauge is provided with sensitive grids in two directions of 0 DEG and 90 DEG and is used for monitoring circumferential and axial strain.
In some embodiments of the present invention, as shown in fig. 2, 12, 3, 6 and 9 points of the pipe section are selected as measuring point areas, and three strain gauges are arranged in each measuring point area, so that the validity of data is ensured, and meanwhile, monitoring interruption caused by failure of the strain gauges is avoided.
In some embodiments of the invention, strain monitoring is performed when backfilling the earth after the buried pipeline is provided with strain gages. Because the earthwork backfill can cause disturbance, the strain gauge can be damaged, strain monitoring is needed, the strain gauge is guaranteed not to be damaged in the construction process, and data acquisition is guaranteed not to be disconnected.
Step 4: and backfilling buried soil, setting a settlement monitoring device on the surface of the monitoring pipe section, debugging equipment, recording the working internal pressure of the pipeline by adopting a pipeline working valve table after the strain monitoring system displays the zero balance of strain gauge monitoring data, starting to monitor the pipeline strain and the foundation settlement, writing a program, calculating the circumferential stress and the axial stress of the pipeline caused by the foundation settlement according to the pipeline strain monitoring data and a stress-strain formula, and outputting the calculated pipeline ring, axial additional stress data and foundation settlement data.
In some embodiments of the invention, the stress-strain formula is:
in sigma hc Adding stress to the measured circumferential direction, and MPa; sigma (sigma) zc For the measured axial additional stress, MPa, the measured circumferential additional stress and the measured axial additional stress are the measured corresponding forces after the system is zeroed; e is the elastic modulus of the pipeline and MPa; μ is poisson's ratio of the pipeline; epsilon h Is the measured hoop strain; epsilon z Epsilon for the measured axial strain h And epsilon z All measured by biaxial strain gages.
In some embodiments of the invention, the monitoring is a stress result relative to the initial pipe pressure, the data is continuously optimized in acquisition and processing, if a pressure regulating process occurs in the pipeline operation, the pipeline stress change caused by the pipeline working internal pressure change is considered, and part of the strain monitoring data is caused by the internal pressure change, and the stress caused by the corresponding pipeline working internal pressure is subtracted from the initial pipe pressure. Of course, the amount of the monitoring data is continuously increased, a large amount of data can be used for training and verification, and then the polynomial return model can be continuously corrected.
If the internal pressure of the pipeline is adjusted during the pipeline stress monitoring process, the internal pressure change also causes the pipeline strain change, the strain change is recorded by strain monitoring, the recorded strain change comprises two factors of foundation settlement and internal pressure change, the part of the internal pressure needs to be subtracted to influence caused by the foundation settlement, the calculation modes of the measured annular additional stress and the measured axial additional stress are as follows, and the axial additional stress of the pipeline after pressure adjustment is calculated by the following formula:
in sigma hc Adding stress to the measured hoop; sigma (sigma) h The pipeline circumferential additional stress caused by foundation settlement is applied; Δp is the internal pressure change value of the pipeline, the pressure rise is positive, D is the external diameter of the pipeline, and mm; delta is the wall thickness of the pipeline, and mm; sigma (sigma) zc For the measured axial additional stress, σ z And adding stress to the axial direction of the pipeline caused by foundation settlement.
In some embodiments of the invention, the sedimentation monitoring device is a hydrostatic level.
In some embodiments of the present invention, the resulting pipeline add-on stress for each station and foundation settlement data are shown in fig. 5 and 6.
Step 5: and a wireless data transmission device is built near the monitoring pipe section, the wireless data transmission device is transmitted to a signal transfer receiver through a signal base station, then stress monitoring data and foundation settlement data are transmitted to a central control room of a natural gas station through signals, and management personnel of the central control room of the station receive the data through a terminal, so that real-time online monitoring is realized.
In some embodiments of the present invention, the wireless data transmission device may employ any of bluetooth, wiFi, and broadband.
Step 6: and checking the pipeline stress, wherein the stress value of stress monitoring is the pipeline additional stress caused by foundation settlement, the relative stress is measured, the pipeline stress is also generated by the working internal pressure of the pipeline, the stress caused by the two factors is combined and overlapped, and the current Von-Mises equivalent stress of the pipeline is checked and calculated through a Von-Mises yield criterion.
In some embodiments of the present invention, the Von-Mises equivalent stress is calculated as:
in the method, in the process of the invention,
representing the Von-Mises equivalent stress of the pipeline and MPa; sigma (sigma) H 、σ Z 、σ J The principal stresses in three directions (axis, ring, diameter) are expressed in MPa.
Wherein, the pipeline meets the thin-wall characteristic, the radial main stress sigma J Far less than the stress in other two directions, can be ignored and has the value of 0. Principal stress sigma in axial direction H And principal stress sigma in the circumferential direction Z The calculation formula of (2) is as follows:
σ H ＝σ h +σ pH
σ Z ＝σ z +σ pZ
in the method, in the process of the invention,
wherein sigma pH The circumferential stress of the pipeline caused by the working internal pressure of the pipeline is MPa; sigma (sigma) pZ The axial stress of the pipeline caused by the working internal pressure of the pipeline is recorded in the step 4, and P is the working internal pressure of the pipeline and MPa; d is the outer diameter of the pipeline, and mm; delta is the wall thickness of the pipeline, mm.
In some embodiments of the present invention, as shown in FIG. 7, von-Mises equivalent stress at each site is obtained.
Step 7: and (3) grading the stress risk of the pipeline, and grading the stress of the pipeline, so that the level of the stress of the pipeline is known conveniently, and the risk is prevented conveniently. According to the pipeline stress monitoring result and the pipeline Von-Mises stress result, the current pipeline risk condition is reflected in a combined mode, so that the influence of sedimentation and working internal pressure on the pipeline can be distinguished, which influence is dominant, and specific corresponding measures are taken.
In some embodiments of the invention, as shown in Table 1, stages I, II, III, IV are graded by Von-Mises equivalent stress, which is the stress level of the pipe as a whole; A. the B, C, D grade is the settlement additional stress to be monitored, and only the influence caused by settlement is considered according to the maximum value of the pipeline circumferential additional stress and the axial additional stress caused by foundation settlement obtained in stress monitoring as a judgment standard.
TABLE 1 pipeline stress classification
Note that: the stress monitoring stress has positive and negative values (positive represents tensile stress and negative represents tensile stress), and sigma s Is the minimum yield strength of the pipeline material.
Two sets of reference factors, 4 indices each, form a 4 x 4 risk matrix.
TABLE 2 pipeline risk matrix
The influence of foundation settlement is shown by a stress monitoring value, the total stress of the pipeline is shown by Von-Mises equivalent stress, the pipeline stress is influenced by the internal pressure of the pipeline and the foundation settlement, the influence of the pipeline is serious can be identified by establishing a risk matrix, and a targeted countermeasure, such as A III level, is adopted, the pipeline stress is larger, but the influence caused by settlement is smaller, which indicates that the pipeline is greatly influenced by the internal pressure of the pipeline, and the pipeline stress can be reduced by adjusting the internal pressure of the pipeline.
Step 8: constructing a polynomial mathematical expression of the pipeline Von-Mises stress, the pipeline working internal pressure and the foundation settlement by using the pipeline Von-Mises stress value, the pipeline working internal pressure and the foundation settlement, and fitting a regression expression of the pipeline stress, the pipeline working internal pressure and the foundation settlement by polynomial regression;
and selecting polynomial regression prediction, randomly dividing the monitored data set into a training set and a verification set, fitting the data of the training set into an optimal pipeline stress prediction relational expression through stepwise regression, and checking through the data of the verification set.
In the oil and gas pipeline specification of China, the possible permanent load, variable load and accidental load of the pipeline are required to be considered in combination, the site buried pipeline is mainly affected by working internal pressure and foundation settlement, and the correlation between the pipeline stress and foundation settlement and the pipeline working internal pressure is analyzed through data processing software, as shown in fig. 4. According to the monitoring of pipeline stress and settlement of a certain natural gas station, the obvious correlation exists between the pipeline stress and the working internal pressure of the pipeline and the foundation settlement, and the expression of the pipeline stress, the working internal pressure of the pipeline and the foundation settlement can be fitted through polynomial regression.
Step 9: and predicting future foundation settlement according to the monitored foundation settlement data by using a gray prediction model method, substituting the foundation settlement prediction value and the pipeline working internal pressure into a regression expression, and predicting the equivalent stress of the pipeline Von-Mises under the future settlement condition, so that a pipeline manager can predict risks in advance.
The internal pressure of the pipeline work can be regulated through a pipeline operation pipe, foundation settlement cannot be controlled manually, settlement data are predicted through a gray model, and predicted future foundation settlement data and pipeline work internal pressure data are substituted into a pipeline stress regression expression fitted in the step 8, so that the predicted pipeline stress is obtained.
The stress monitoring data, foundation settlement data, pipeline Von-Mises stress, pipeline working internal pressure and pipeline prediction data are formed into a visual window by programming, and pipeline management staff can directly see the pipeline section stress change and the fluctuation condition through a computer, and predict the future stress condition of the pipeline.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limiting of the implementation method of the present invention. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Modifications, equivalents, and improvements within the spirit and principles of the present invention are intended to be included within the scope of the following claims.
Claims (8)
1. The method for monitoring and early warning the stress of the buried pipeline of the natural gas station under the foundation settlement effect is characterized by comprising the following steps of:
drawing a three-dimensional model of the buried pipeline, introducing the three-dimensional model into finite element analysis software, determining a finite element constitutive equation, establishing a finite element model, performing finite element numerical simulation to obtain a stress cloud picture, determining a pipe section with larger stress of the buried pipeline through the stress cloud picture, and determining a pipe section needing stress monitoring;
arranging a double-shaft strain gage on a pipe section needing to be subjected to stress monitoring, wherein the double-shaft strain gage is used for monitoring additional circumferential and axial strain of the pipe section caused by foundation settlement;
setting a settlement monitoring device on the surface of the monitoring pipe section, and carrying out pipeline additional strain monitoring and foundation settlement monitoring to obtain additional circumferential and axial strain data and foundation settlement data;
outputting the monitored additional circumferential and axial strain data into the pipeline additional circumferential stress and the pipeline additional axial stress through a stress-strain formula;
the monitoring data is transmitted to a central control room of the natural gas station through the wireless data transmission device and the signal base station, so that real-time online monitoring is realized;
checking and calculating the current Von-Mises equivalent stress of the pipeline according to the Von-Mises yield criterion;
constructing a polynomial mathematical expression of the equivalent stress of the pipeline Von-Mises, the internal pressure of the pipeline work and the foundation settlement by utilizing the equivalent stress of the pipeline Von-Mises, the internal pressure of the pipeline work and the foundation settlement, and fitting a regression expression of the pipeline stress, the internal pressure of the pipeline work and the foundation settlement by polynomial regression;
predicting future foundation settlement according to the monitored foundation settlement data by using a gray prediction model method, substituting a foundation settlement prediction value and pipeline working internal pressure into a regression expression, and predicting the equivalent stress of the pipeline Von-Mises under the future settlement condition;
wherein, the calculation formula of Von-Mises equivalent stress is:
in the method, in the process of the invention,
representing the Von-Mises equivalent stress of the pipeline; sigma (sigma) H 、σ Z 、σ J Representing the principal stresses in the shaft, ring, and radial directions, respectively;
radial principal stress sigma due to the pipe meeting the thin-wall characteristics J Far less than the other two directions, ignoring the radial principal stress sigma J The value is 0, and the axial main stress sigma H And principal stress sigma in the circumferential direction Z The calculation formula of (2) is as follows:
σ H ＝σ h +σ pH
σ Z ＝σ z +σ pZ
in the method, in the process of the invention,
wherein sigma pH Is the hoop stress of the pipeline caused by the internal pressure; sigma (sigma) pZ Is the axial stress of the pipeline caused by the internal pressure,p is the working internal pressure of the pipeline; d is the outer diameter of the pipeline; delta is the wall thickness of the pipeline.
2. The method for monitoring and early warning the stress of a buried pipeline in a natural gas yard under the action of foundation settlement according to claim 1, wherein a pipeline stress risk rating is also established to evaluate the current pipeline stress level, the pipeline stress risk rating comprises grading by Von-Mises equivalent stress to evaluate the stress level of the whole pipeline, and the method further comprises adopting the maximum value of the pipeline circumferential additional stress and the axial additional stress obtained in the stress monitoring to evaluate the settlement additional stress to obtain the risk rating.
3. The method for monitoring and early warning the stress of the buried pipeline of the natural gas station under the action of foundation settlement according to claim 1, wherein the method can also realize data visualization through program codes and output monitoring data, calculation data, prediction data and pipeline risk level through a computer program window.
4. The method for monitoring and early warning the stress of the buried pipeline of the natural gas station under the foundation settlement effect according to claim 1, wherein the buried pipeline three-dimensional model is drawn before the buried pipeline is further drawn, and the physical parameters of the pipeline and the buried pipeline are obtained by collecting buried soil information of the natural gas station.
5. The method for monitoring and early warning the stress of buried pipelines in a natural gas station under the action of foundation settlement according to claim 4, wherein the physical parameters of the pipelines comprise pipe diameter, pipe thickness, density, poisson ratio and tensile strength, and the physical parameters of the buried pipelines comprise uniaxial tensile strength, triaxial tensile strength, density, internal friction angle and cohesive force.
6. The method for monitoring and pre-warning the stress of buried pipelines of a natural gas station under the action of foundation settlement according to claim 1, wherein the stress-strain formula is as follows:
in sigma hc Adding stress to the circumferential direction of the measured pipeline; sigma (sigma) zc Axially adding stress to the measured pipeline; e is the elastic modulus of the pipeline; μ is poisson's ratio of the pipeline; epsilon h Is the measured hoop strain; epsilon z Is the measured axial strain.
7. The method for monitoring and early warning the stress of a buried pipeline in a natural gas station under the action of foundation settlement according to claim 1, wherein if a pressure regulating process occurs in the pipeline operation, the internal pressure of the pipeline is changed to cause the stress change of the pipeline, and the stress-strain formula is:
in sigma hc Adding stress to the circumferential direction of the measured pipeline; sigma (sigma) h The pipeline circumferential additional stress caused by foundation settlement is applied; sigma (sigma) zc Axially adding stress to the measured pipeline; sigma (sigma) z Additional stress is axially added to the pipeline caused by foundation settlement; Δp is the internal pressure change value of the pipeline, the pressure rise is positive, and D is the external diameter of the pipeline; delta is the wall thickness of the pipeline.
8. The method for monitoring and early warning the stress of buried pipelines of a natural gas station under the action of foundation settlement according to claim 1, wherein the settlement monitoring device is a static level gauge.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3305705B1 (en) * | 2001-10-25 | 2002-07-24 | 住友ゴム工業株式会社 | Tire running simulation method |
| CN103258063A (en) * | 2012-02-15 | 2013-08-21 | 同济大学 | Complete water and soil coupling based land subsidence information processing method |
| CN103437318A (en) * | 2013-08-29 | 2013-12-11 | 中国水电顾问集团华东勘测设计研究院 | Method for calculating and predicating post-construction settlement of suspension seawall |
| CN109388865A (en) * | 2018-09-25 | 2019-02-26 | 武汉大学 | The shaft tower emergency early warning method for failure under operating condition is settled a kind ofly |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7363173B2 (en) * | 2004-06-01 | 2008-04-22 | California Institute Of Technology | Techniques for analyzing non-uniform curvatures and stresses in thin-film structures on substrates with non-local effects |
| US7093494B2 (en) * | 2004-10-18 | 2006-08-22 | Silverbrook Research Pty Ltd | Micro-electromechanical pressure sensor |
| JP2007205860A (en) * | 2006-02-01 | 2007-08-16 | Sekisui Jushi Co Ltd | Method for evaluating durability of existing sign pole and baseline setting method for executing durability evaluation of existing sign pole |
| JP6601762B2 (en) * | 2015-09-11 | 2019-11-06 | 株式会社日本製鋼所 | Steel heat treatment simulation method and steel heat treatment simulation program |
| CN106355002B (en) * | 2016-08-26 | 2018-07-24 | 中国石油天然气集团公司 | It is a kind of that based on pipeline, there are the method for early warning of axial direction monitor stress when pipe laying with elastic bending |
| CN106404260B (en) * | 2016-08-26 | 2018-12-25 | 中国石油天然气集团公司 | A kind of method for early warning based on pipeline axial direction monitor stress |
| CN109753670B (en) * | 2017-11-04 | 2022-06-07 | 中国石油化工股份有限公司 | Method and device for evaluating strength of non-anchored storage tank after foundation settlement |
| CN109708008B (en) * | 2019-01-23 | 2019-11-05 | 北京市燃气集团有限责任公司 | Monitoring pipeline safety and method for early warning |
| CN111307031B (en) * | 2020-03-16 | 2020-11-10 | 西南石油大学 | Buried pipeline safety state monitoring and early warning method |
| CN112016255B (en) * | 2020-10-29 | 2021-01-26 | 西南石油大学 | Method for predicting pipeline suspended failure under flood action |
| CN112924065A (en) * | 2021-01-25 | 2021-06-08 | 华南理工大学 | Measuring method for measuring residual stress of curved surface based on blind hole method |
| CN112924061A (en) * | 2021-01-29 | 2021-06-08 | 华南理工大学 | Wireless real-time monitoring system and method for non-uniform settlement stress of natural gas pipeline |
| CN113237770A (en) * | 2021-05-10 | 2021-08-10 | 浙江大学 | Device and method for testing residual strength of corroded pipeline |
-
2022
- 2022-02-24 CN CN202210178582.7A patent/CN114636496B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3305705B1 (en) * | 2001-10-25 | 2002-07-24 | 住友ゴム工業株式会社 | Tire running simulation method |
| CN103258063A (en) * | 2012-02-15 | 2013-08-21 | 同济大学 | Complete water and soil coupling based land subsidence information processing method |
| CN103437318A (en) * | 2013-08-29 | 2013-12-11 | 中国水电顾问集团华东勘测设计研究院 | Method for calculating and predicating post-construction settlement of suspension seawall |
| CN109388865A (en) * | 2018-09-25 | 2019-02-26 | 武汉大学 | The shaft tower emergency early warning method for failure under operating condition is settled a kind ofly |
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