Grant: Alliance Grants

The aim of this project is to explore and account for the soil-induced failure of pipeline coatings and subsequent corrosion of pipe material leading to loss of pressure integrity in buried pipelines. It is in the best interest of everyone to ensure that pipeline infrastructure is safe and reliable because any significant disruption to buried pipeline systems can result in undesirable impacts on the environment and the quality of life of those affected. One significant threat to buried pipeline integrity - i.e., maintaining safe pipeline operation without loss of product - arises from the failure of protective coatings and the resulting corrosion of pipe material in the soil. This is a complex engineering problem that is not well understood, and there is a need to advance the knowledge on this front through systematic research. The key outcomes to be achieved from this study are as follows: (a) elucidation of the effect of coating defects, including those caused by pipe-soil interactions, on coating degradation and the associated rate of pipe corrosion, (b) the effect of coating ageing, degradation, and relative soil movements (under different backfill soil conditions, soil stress, etc.) on the soil-coating interface, (c) development of a numerical model for simulating coating degradation under soil movement and an improved corrosion model considering time-dependent coating degradation due to soil movement and, (d) development of new design criteria or standards for engineering the pipe coating-soil interface. The outcomes from this study will enable improved pipeline design through effective selection of pipeline coatings, calculation of soil corrosion rates and development of guidelines for the properties to be used in soil-pipe interaction assessments.