Dynamic performance prediction and influencing factors analysis of buried polyethylene pipelines under subsurface localized explosion

Although polyethylene (PE) pipelines have been extensively used in engineering fields, very little effort has been devoted to their abilities against blast loads. In the present study, numerical method is used to predict the dynamic performance of buried small-diameter PE pipelines under subsurface localized explosion. The effectiveness of a numerical model was firstly evaluated to entirely replicate the experimental damage process of PE pipelines. Then, parametric studies are performed to show the dynamic response of PE pipelines under subsurface localized explosion. Finally, the main influencing factors are analyzed according to the grey system theory. The results show that the front and back faces, top and bottom of the pipelines, where facing explosive charge are the main failure positions of PE pipelines due to the local effect of blast load. The peak pressure, resultant displacement, peak effective strains, and peak vibration velocities of the PE pipelines increase with the explosive mass increasing. The peak pressures and peak vibration velocities decrease with the pipe size decreasing. Reducing the pipe size could increase the maximum effective strain of the pipe facing the explosive center, and reduce the vibration velocity of the pipe near the explosive center. The change law of peak pressure of PE pipelines caused by changing explosive mass and pipe size is different from that of peak vibration velocity of PE pipelines. As a sequence, the three influencing factors (explosive mass, pipe size and blasting distance) should also be considered to analyze the influence of subsurface explosion on the buried small-diameter PE pipelines.