Grant: Collaborative Research and Development Grants

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