| Steel pipelines are the most economical and efficient mode of transporting oil and natural gas. When buried pipelines pass through discontinuous permafrost regions in Canadian north, local buckling appears in the pipe wall due to extremely high stresses generated by frost heave, slope moment and thaw settlement of the soil. Several wrinkles have been found in Norman Wells line in Northwest Territory since 1998.; The common rehabilitation method is to replace the wrinkled section of the pipe with unwrinkled one. This method is extremely expensive. Another method is to provide external steel sleeve on the wrinkled portion of the pipe however studies have revealed that this method is not effective in the long run.; This research program is designed to develop optimum repair techniques using fibre reinforced polymer (FRP) composites. Experiments and finite element analysis (FEA) have been used. The effects of several repair techniques on the behaviour of the pipe are discussed and effective repair techniques are developed. |
