Field Performance and Analysis of Large-Diameter High-Density Polyethylene Pipe under Deep Soil Fill

This paper presents field performance of $\mathrm{1,524}\text{-}\mathrm{mm}$ $\left(60\text{-}\mathrm{in.}\right)$ diameter, corrugated high-density polyethylene (HDPE) pipes installed at the Ohio University–ORITE deep burial site. The pipes have been subjected to $6.1\text{-}\mathrm{m}$ $\left(20\text{-}\mathrm{ft.}\right)$ or $12.2\text{-}\mathrm{m}$ $\left(40\text{-}\mathrm{ft.}\right)$ high embankment fill for about $2\text{years}$ . Structural performance of each pipe was monitored with various sensors during initial backfilling, during embankment construction, and after embankment construction. The data accumulated in the field indicated that these pipes were performing satisfactorily, showing little signs of structural distress. Examination of the field data revealed some valuable insights into the large-diameter, flexible pipe performance under deep soil cover. In addition, selected analytical methods were evaluated using the field data. An improved approach based on the modified Iowa formula was generally effective in estimating the horizontal deflection. Elastic solutions showed a limited ability in describing the field performance of these large-diameter HDPE pipes. The powerful nature of the finite element computer program CANDE-89 was recognized but not fully demonstrated in numerical simulations of the field installation conditions because of a few shortcomings in CANDE-89 computer analysis.