Buckling of HDPE liners under external uniform pressure

Lining of underground pipeline networks with deformed/reformed high-density polyethylene (HDPE) liners is a trenchless technique frequently specified for rehabilitation. According to the current design practice, a liner can b e structurally designed as a flexible pipe, rigid pipe, or composite pipe, depending on installation conditions. One of the most important design cons iderations of a confined liner is its buckling under a uniform pressure sim ilar to that exerted by ground water seeping through the deteriorated host pipe. Because long-term testing of a lining system is both time-consuming a nd expensive, it becomes extremely important to establish a design criteria for long-term conditions more quickly and economically. In the reported st udy, over 200 short-, medium- and long-term tests were performed to examine the effects of the diameter, thickness, and deformities on the buckling ch aracteristics of a HDPE liner pipe. Based on the findings of the study, som e recommendations were proposed for the design and testing of plastic liner s under short- and long-term loading conditions.