PIPELINE CROSSING FAULT LINE
PIPELINE CROSSING FAULT LINE
(OP)
I need some guidence on how to cope with the movement in a pipeline which transverses a fault line. We were given the movement as approximately 1 inch per year. References and personal experience will be appreciated.





RE: PIPELINE CROSSING FAULT LINE
I believe there have been numerous test and/or perhaps other installations of ductile iron piping across known fault lines over many years, and I suspect most crossings at least in recent years have employed at least some special provisions by the designers. I am not aware of any specific results of any such installations (other than I have not heard of any problems where provisions such as multiple ball joints in the area etc., have been employed). For more/better information you might wish to contact the Ductile Iron Pipe Research Association (DIPRA / dipra.org). I suspect a very strong piping with some significant flexibility built into the design may be advantageous for minimal risk, and particularly in known fault areas.
RE: PIPELINE CROSSING FAULT LINE
While I don’t think noted in Mr. Nyman's lecture, at the time this was perhaps one of the greatest if not the greatest pipeline project in history, and perhaps most significantly as noted in multiple recent publications, "More than 14 billion barrels of oil have moved" through this pipeline. I think the carrier pipe for this project was produced in Japan and American Steel Pipe (a division of ACIPCO) furnished significant other piping material for some 78,000 (most if not all) of the VSM’s for this massive pipeline project.
I believe Mr. Nyman also mentioned in his presentation that some other contemporary fault crossings at least of some more recent buried energy pipelines are now being designed buried in special wide and rather shallow trapezoidal cross-section trenches, apparently with some special (uncompacted) backfill.
RE: PIPELINE CROSSING FAULT LINE
Was the 1" per year average rate of displacement based on a creeping fault or based on a 100 year average, where primary displacements occur at significant siesmic events. I previously worked for a gas utility that had numerous pipelines crossing numerous faults, including the San Andreas. Only conventional pipeline design was used in their construction. In significant seismic events, pipe near the epicenter was unearthed and invesigated for damage. In one case nearly two miles were unearthed and the pipe allowed to spring back (up to 5 feet)into place to remove lateral earth loadings.
It is noted that as of 1980 when I left that company, no electric arc welded pipe had ever failed during a quake, although numerous failures occurred in oxy-fuel gas welds due to their inherent brittle nature.