Thermoplastic Pipe Deep Burial Study in Ohio: Further Analysis of Field Performance Data

Abstract

In 2002, the Ohio Research Institute for Transportation and the Environment completed one of the most comprehensive field studies ever undertaken on thermoplastic pipes, involving 18 instrumented test pipes in a variety of installation conditions and subjected to either 6.1-m (20-ft) or 12.2-m (40-ft) high soil cover loading for a prolonged period of time. The ORITE researchers will continue to monitor the field performance of the test pipes for up to five years beyond the end of construction. The field performance data obtained during the initial phase of the project were recently reevaluated. The extensive volume of the data was analyzed further to gain additional insights into the field performance of thermoplastic pipes subjected to relatively deep soil fill. Particular attention was paid to the circumferential shortening behavior of the pipes, which has been rarely monitored by previous researchers. This paper presents the findings made while reviewing their field data. On the basis of these latest findings, a suggestion is made on how a better estimate of the vertical deflection of the buried thermoplastic pipe may be made, especially when the pipe is installed under relatively deep soil fill.