Analysis of jointed HDPE pipe

For long-term service, it is difficult to ensure that the surrounding backfill environment will remain uniform along the pipe as in the installation stage. The backfill modulus can also vary along the pipe because of the degree of saturation and the density of backfill soil changing with time. Also, improper installation of the pipe and backfill soil can cause non-uniformity. Therefore, a need was identified to evaluate the long-term performance of the pipe, buried in non-uniform backfill conditions. This was addressed by an investigation of jointed pipes with the joints at the interfaces of two different soil media, simulating non-uniformity of the backfill. Jointed and soil-embedded high-density polyethylene pipe subjected to live loading was studied in soil chamber for the level of the maximum service loading, and, the problem was modelled by finite element method, in this study. Field measurements and Finite Element results were evaluated by ASTM standard. It seems to be the governing failure criterion, but no creep-rupture had been observed during the experiment.