Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2019-2020).

Pipelines play an important role in modern society through transporting liquids and gases from the source to thex000D
users. According to Natural Resources Canada, about 825,000 kilometers of oil and gas transmission, gatheringx000D
and distribution pipelines traverse Canada. Many of these pipelines pass through the areas prone to landslides.x000D
Soil movement due to landslides may cause longitudinal, transverse or combined loads on the pipelines,x000D
depending upon the orientation of the pipeline with respect to the moving ground. The existing designx000D
guidelines for structural integrity assessment of pipelines in landslide areas were developed based on thex000D
observations for rigid pipes, which may not be applicable to flexible pipes, such as Medium Densityx000D
Polyethylene (MDPE) pipes. However, flexible polyethylene pipes including MDPE pipes have been widelyx000D
used over the last few decades due to their various advantages. The design method for the assessment of thex000D
performance of MDPE pipelines subjected to landslide loading is not well-developed. Full-scale tests and finitex000D
element (FE) modelling of MDPE are also very limited. In the proposed research, a set of full-scale tests ofx000D
small diameter MDPE pipe will be conducted using the facility at Memorial University of Newfoundlandx000D
(MUN) to develop a database and an improved understanding on the behaviour of pipes under the loads fromx000D
ground movements. The test program will consists of following: i) axial pullout testing of plane pipes; ii) axialx000D
pullout testing of pipes with Tee-junctions (branched pipes); and iii) lateral pullout testing for pipes, buried inx000D
loose and dense sand. Laboratory element testing will be conducted to find geotechnical parameters andx000D
development of constitutive models for sand and the strain rate dependent behavior of MDPE pipe materials.x000D
FE modelling techniques will be developed using Abaqus FE software to simulate the observed response fromx000D
the full-scale pipe tests. The findings from this research will be useful to the Canadian pipeline industry,x000D
enabling them to assess pipeline conditions in unstable ground and thus to make more effective managementx000D
decisions to ensure structural integrity of the pipeline and minimize the risk of pipeline failure.