Study on the calculation method and structural dynamic response of buried pipeline subjected to external explosion...

Area of Science:

• Geotechnical Engineering
• Mechanical Engineering
• Computational Fluid Dynamics

Background:

• Buried pipelines are vulnerable to external explosion loads, potentially causing significant stress and deformation.
• Understanding pipeline response to explosions is critical for infrastructure safety and integrity.

Purpose of the Study:

• To establish and validate a multiphase coupled numerical model for analyzing buried pipeline responses to external explosions.
• To investigate the influence of pipeline content (oil vs. gas) and internal fluid velocity on pipeline structural integrity under explosion conditions.

Main Methods:

• Development of a multiphase coupled model incorporating pipeline, soil, and internal fluid dynamics.
• Utilizing a penalty function coupling method for soil-pipeline and fluid-pipeline interactions.
• Derivation of a multiphase coupled global solution variational principle function for the soil-pipe-fluid system.
• Numerical simulation and experimental validation, achieving a maximum error of approximately 5%.

Main Results:

• The peak explosion pressure in the soil surrounding gas pipelines is higher than that for oil pipelines.
• Oil pipelines demonstrate superior structural response, with reduced maximum radial displacement (3.83 mm) and stress (3.75%) compared to gas pipelines.
• Increased internal fluid velocity (1.5 m/s vs. 1 m/s) leads to greater radial displacement (2.65 mm) and stress (5.72%) in the pipeline.

Conclusions:

• The validated multiphase coupled model accurately predicts buried pipeline behavior under external explosions.
• Oil pipelines possess inherently better deformation and explosion resistance than gas pipelines.
• Higher internal fluid velocities significantly compromise pipeline resistance to deformation and explosion impacts, highlighting operational safety considerations.