Cryogenic issues of operating railway embankments in the eastern section of the Baikal-Amur Mainline and deformation development scenarios

   To ensure the reliable and safe operation of embankments on the Eastern section of the Baikal-Amur Mainline (BAM), including after modernization or repair, it is essential to eliminate or minimize cryogenic deformations of the structures. This goal is facilitated by improving the effectiveness of anti-deformation measures through an objective assessment of existing cryogenic issues, as well as the systematic analysis and forecasting of scenarios for further deformation development in the embankments of the studied section.
   Based on the historical aspects of the construction and operation of BAM, current cryogenic problems within this section have been summarized and formulated. Eight potential scenarios for the development of cryogenic deformations in embankments on the Eastern section of BAM have been outlined and categorized. For the probabilistic forecasting of deformation development scenarios and to determine priority directions for developing effective stabilization solutions for the “embankment – foundation” system, a survey of embankments on this section was conducted.
   The results of the survey on embankments across five intervals revealed specific characteristics of their current condition and deformation patterns. The embankments on the Eastern section of BAM not only reflect the consequences of past degradation of permafrost in their foundations, but they also possess a potential for deformation under continued operation, including post-modernization and repairs. These deformations may occur with particular characteristics and according to various scenarios.
   The probabilistic forecast of cryogenic deformation scenarios indicated that the most likely deformation scenario for embankment sections on this stretch is the subsidence of structures due to permafrost degradation in the foundation during thaw periods. The probability of other scenarios is relatively low (up to 15 %), though they do exist and must be considered in future modernization or repair activities. A significant portion of the forecasted scenarios (up to 30 %) combine multiple cryogenic issues simultaneously. Against this background, further research and theoretical justification of complex thermal stabilization solutions become increasingly relevant.

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