Axial Elongation and Contraction of Buried Pipe due to Change in Temperature and Pressure

A method to estimate the maximum axial displacement at the free ends of unanchored buried pipe due to changes in temperature and pressure is necessary, among other things, to evaluate connections, develop slip or deformable couplers, and apply couplers in design. The problem is represented by a simple one-dimensional model in which thermoelastic pipe slips through embedment as it elongates or contracts axially due to temperature and pressure change. Axial movement is resisted only by stick-slip frictional resistance at the pipe-embedment interface. Dimensional analysis suggests that buried pipe maximum axial displacement for long pipe might be described using four dimensionless parameters. A relationship between the dimensionless products is discussed. The results advance understanding of buried pipe behavior and provide a basis for additional research. Experimentation needed to evaluate the hypothesized relationship is discussed.