Incorporating climate warming scenarios in coastal permafrost engineering design - Case studies from Svalbard and northwest Russia

Climate change is predicted to strongly affect the evolution of the Arctic coast over the coming decades. The continuous warming trend observed in Svalbard and northwest Russia since the 1980s are creating concerns related to the stability and durability of existing infrastructure on permafrost and uncertainties related to the design of new structures and infrastructure in the region. An increase in ground temperatures may reduce the bearing capacity and increase settlement rates and subsidence of foundations, and stability of natural and engineered slopes. The effect of climate warming in permafrost regions may cause unacceptable risks according to existing engineering design criteria. A methodology is suggested where the output from climate models can be used as input to engineering models assessing change in the ground thermal regime at site specific locations in permafrost regions. The main objective has been to determine the computed warmest ground temperature occurring during the service life time of the structure, taking climate warming scenarios into consideration. This type of information can be used in coupled thermo-dynamic and mechanical models of the local geotechnical site conditions including structural elements such as foundations, port structures, transportation systems and pipelines. Site specific data from statistical downscaling of General Circulation Models (GCMs), and soil and permafrost data from research sites in Svalbard and northwest Russia has been used in a transient geothermal model to compute possible future ground temperatures in the areas. The results show that depending on the soil conditions and current permafrost temperatures, the sensitivity to climate warming vary from small or negligible to considerable. Further development of the methodology advocates a probabilistic approach. (C) 2016 Elsevier B.V. All rights reserved.