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Frequency spectrum method-based stress analysis for oil pipelines in earthquake disaster areas.

Wu X, Lu H, Huang K, Wu S, Qiao W - PLoS ONE (2015)

Bottom Line: To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis.Feasible project enhancement suggestions based on the analysis results are proposed.The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan, China; School of Civil Engineering and Architecture, Southwest Petroleum University, Chengdu, Sichuan, China.

ABSTRACT
When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

Show MeSH
Distribution of displacement in axial, longitudinal and transverse directions of static pipeline.
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pone.0115299.g006: Distribution of displacement in axial, longitudinal and transverse directions of static pipeline.

Mentions: Figs. 6–9 shows the axial, longitudinal and transverse displacement distributions along the pipeline under static conditions and earthquake activity, respectively. The displacement during earthquake activity is calculated using the SRSS (Square Root of the Sum of the Squares) method [53–60] (This is one of the many types of modal combination method. This method assumes that events involved in data processing are completely independent of each other. When the difference between natural vibration states of a structure or between the natural vibration frequencies is large, it can be approximately considered that the vibration of each mode is independent of each other, so that a better result can be obtained, but the symbol of the vibration model cannot be displayed.). All calculated values are positive, which indicates the pipeline’s maximum distance at a certain moment but does not show the movement direction; therefore, the static displacement situation has been presented separately. Fig. 10 displays the distribution of stress ratios along the pipeline under static conditions and earthquake activity. Based on Figs. 6–10, the following can be concluded:


Frequency spectrum method-based stress analysis for oil pipelines in earthquake disaster areas.

Wu X, Lu H, Huang K, Wu S, Qiao W - PLoS ONE (2015)

Distribution of displacement in axial, longitudinal and transverse directions of static pipeline.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4334484&req=5

pone.0115299.g006: Distribution of displacement in axial, longitudinal and transverse directions of static pipeline.
Mentions: Figs. 6–9 shows the axial, longitudinal and transverse displacement distributions along the pipeline under static conditions and earthquake activity, respectively. The displacement during earthquake activity is calculated using the SRSS (Square Root of the Sum of the Squares) method [53–60] (This is one of the many types of modal combination method. This method assumes that events involved in data processing are completely independent of each other. When the difference between natural vibration states of a structure or between the natural vibration frequencies is large, it can be approximately considered that the vibration of each mode is independent of each other, so that a better result can be obtained, but the symbol of the vibration model cannot be displayed.). All calculated values are positive, which indicates the pipeline’s maximum distance at a certain moment but does not show the movement direction; therefore, the static displacement situation has been presented separately. Fig. 10 displays the distribution of stress ratios along the pipeline under static conditions and earthquake activity. Based on Figs. 6–10, the following can be concluded:

Bottom Line: To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis.Feasible project enhancement suggestions based on the analysis results are proposed.The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan, China; School of Civil Engineering and Architecture, Southwest Petroleum University, Chengdu, Sichuan, China.

ABSTRACT
When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

Show MeSH