Advanced Soil Pipe Interaction Research Professor Dharma Wijewickreme Department of Civil Engineering University of British Columbia Presented by: Jeremy Groves
Advanced Soil Pipe Interaction Research
Professor Dharma Wijewickreme
Department of Civil Engineering
University of British Columbia
Presented by: Jeremy Groves
Presentation Agenda
•Discuss the need to study soil-pipeline interaction,
•Provide an overview of the ASPIReTM program and
testing facility at UBC,
•Look at our current research on the topic of field
monitoring of buried polyethylene natural gas
pipelines subjected to ground movement.
What are pipelines?
•Linear structures spanning over long distances,
•Variability in soils and groundwater,
•Variability of exposure to hazards,
•Crossing of environmentally sensitive zones,
•Cost effectiveness (e.g. optimize pipe size, material type),
•Specific chemical properties of transported liquids/gas.
EVER INCREASING DEMAND TO DESIGN AND CONSTRUCT
PIPELINES WITH REDUCED RISK OF FAILURE!
Problem for pipeline safety & integrity
•Disruption due to landslides, earthquake-induced liquefaction,
stress/stretch corrosion cracking and general loss of integrity
can have significant impact on performance,
•Some quantified risk:•The average costs from significant pipeline damage due to
geotechnical incidents over the past 10 years >$400M/year (twice
that of damage from other hazards). -US Pipeline and Hazardous Materials Safety Administration
•BC’s approx. 40,000 km of pipelines.
Geotechnical hazards to buried pipelines
Liquefaction-induced ground
movementsSlow moving landslides
Rapid landslidesEarth fault movements
Specific challenges faced by geotechnical engineers
•Impact of soil forces on buried pipelines (landslides,
earthquake-induced ground movements),•Permanent relative ground deformations are the key concern in relation to
the performance of buried pipelines.
•Need to minimize soil loads on buried pipelines,•Isolate from hazards,
•Tolerate soil loads from the hazards,
•Eliminate the hazard.
•The key to all of this is to understand the soil-pipeline
interaction.
•Performance and integrity of pipe
under relative movements between
pipe and ground (e.g., landslides,
earthquakes, pipe thermal
movements),
•Predict contact pressure around
the pipe, loads/strains on the pipe.
Wijewickreme et al. (2009)
Importance of soil-pipeline interaction
One of the key purposes of our research is to help develop guidelines
and criteria to determine the amount of ground displacement
associated with the safe operational limits of buried pipelines.
Field monitoring of buried polyethylene natural gas pipelines
subjected to ground movement
•12 year long collaboration with Fortis BC pipeline integrity engineers,
•Previously two M.A.Sc. and one Ph.D. have studied on this topic,
•Developed a new analytical model to account for the soil-pipe
interaction mechanisms in buried MDPE pipes,
•Used to estimate relative ground surface movements needed for
pipe failure.
•Purpose of the current work is to provide a reliable database of
ground movement and associated pipe strain data to further validate
the new closed form solution.
Field monitoring of buried polyethylene natural gas pipelines
subjected to ground movement
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Slo
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Elapsed time (days)
Chilliwack slope movements since initial monitoring
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