Geotechnical Investigations for Arctic Gas Pipelines

Abstract. The sub-surface conditions encountered in the Arctic, critical to a natural gas pipeline design, construction and operation, require a comprehensive investigation and analysis of these conditions before confidence can exist that ground stability can be preserved. The paper outlines the preserved. The paper outlines the geotechnical investigations, analysis and design consideration performed by the Canadian Arctic Gas Study group in evaluating a gas pipeline to the Arctic. Programs covering photo-interpretation, soils investigations, geology, mathematical modelling are explained. The thrust of most Arcticpipeline studies is toward the delineation pipeline studies is toward the delineation and solution of problems related to permafrost. Prior to the Prudhoe Bay permafrost. Prior to the Prudhoe Bay discovery, permafrost research was viewed by many as a scientific luxury and little was known of its characteristics and behaviour. Although permafrost covers one-half of the land area permafrost covers one-half of the land area of Alaska and Canada, the engineering fraternity had demonstrated only a nominal interest into this phenomenon. The value of such information was suspect, and the hostilities of the Arctic environment was generally conceded as the major deterrent to development. our lack of knowledge of permafrost became painfully clear in 1968 and was dramatized by our urgent need for it. The problem was magnified by the public concern and pressures for public concern and pressures for environmental preservation. No longer can the designer be satisfied with are liable and economic design, he must demonstrate that environmental disturbance is maintained with inacceptable limits. The Arctic and sub-Arctic present the supreme challenge in doing present the supreme challenge in doing so. Most of the design and environmental concerns are related, directly or indirectly, to geotechnical problems arising from thermal changes to the permafrost, from any number of sources. permafrost, from any number of sources. Extensive knowledge has been gained in this field and analytical techniques developed to confront most foreseeable problems. problems. The Canadian Arctic Gas Study Limited This consortium developed from the 1972 merger and subsequent expansion of two formerly competitive groups formed to study a natural gas pipeline connection to Prudhoe Bay. By July of 1972, sponsoring companies numbered sixteen and represented production, transmission, and transportation interests.