Buckling of HDPE liners under external uniform pressure

This paper discusses results of an experimental study of the buckling behavior of HDPE liner pipes. None of the tested liners failed structurally by rupturing or breaking. Based on the results of the experimental tests, it was determined that end effects from the testing chamber were effectively eliminated when a length-to-diameter ratio of about 10 was used. Results of the study showed that long-term loading conditions could be evaluated from short-term behavior by employing a suitable load factor. Based on 10,000 hours long-term buckling tests, the load factor was found to be approximately 1/3 for confined, circular liners. The effects of SDR, thickness, and imperfections, such as ovality, eccentricity and offset, must be considered before establishing the long-term loading conditions. A load factor of 4 is recommended for design of liners installed in extremely deformed or deteriorated host pipes.