Elastic Properties of Pipe Materials during Hydraulic Transients

Abstract

The effect of hydraulic transients on water and sewage pipes is studied by measuring the pressure and the strain in pipes simultaneously during field conditions. Both the axial and circumferential strains were recorded for several different pipe materials including cast iron, stainless steel, and polyvinyl chloride (PVC) plastic. Measurements are also performed by exposing a buried pipe and recording the pipe response during transient loading with and without full soil load. In most cases investigated, an assumption of plane strain in the pipe is valid since the pipes were axially restrained from moving. The pipe response during hydraulic transients is generally well described using linear‐elastic theory with a modulus of elasticity corresponding to static loading. A soil load enhances the strength of the pipe, which is indicated by a lower measured strain for a certain pressure in comparison with measurements for cases without soil load, thus having an effect similar to an increase in the modulus of elasticity.