Design and construction of a large-diameter crude oil pipeline in Northeastern China: A special issue on permafrost pipeline

The design and building of a pipeline in permafrost regions challenge engineers and scientists in many regards, and the geohazards resulting from the (differential) frost heaving and thaw settlement of the pipeline foundation soils present one of the most daunting tasks. The China–Russia Crude Oil Pipeline, a spur line from the Siberia–Pacific Pipeline System, presented unique scientific and engineering problems because of: 1) extensive presence of the more ice-rich permafrost in boreal forests and swamps; 2) an insistence on a buried construction mode because of concerns about the potential for frequent forest fires and other safety issues; 3) great uncertainties in the temperatures of oil being transported although the given estimated oil temperature of − 6.4 to + 3.6 °C entering the Moʹhe Pump Station, and the estimated oil temperatures could vary from about − 6 to + 10 °C along the southward pipeline route; 4) the limited lead time for detailed surveys on engineering geology along the pipeline routes and for engineering design; 5) very much limited investment and a limited number of engineers experienced in designing and building a major pipeline in an area where about one-half of its length would be impacted by generally warm (− 3 to 0 °C) permafrost. Nevertheless, the pipeline engineers and permafrost scientists strived to economically build and satisfactorily operate the first major crude oil pipeline in the boreal ecosystem in China. The major results on the formation mechanisms and mitigative measures for the (differential) frost heave and thaw settlement were presented in the eight papers in this special issue on permafrost pipeline, and one additional paper on the Golmud–Lhasa Oil Products Pipeline on the Qinghai–Tibet Plateau was also included. They may provide insights to the understanding of pipeline–permafrost interactions and benefit the future design and construction of pipelines in similar northern environments.