Аннотация:In order to assess the condition of the linear part of the main pipeline installed on supports in the permafrost area, thermal engineering calculations of support foundation grounds are performed for main pipelines. The obtained ground temperature profile is used to determine the safe life of support structures, assign or adjust technical solutions to ensure a specified ground temperature pattern for the foundation support grounds. To ensure reliable thermal engineering calculation results (i. e. to determine necessary and sufficient conditions for correct design parameters), it is necessary to verify the compliance of the engineering survey data with the calculated operation parameters of the pipeline. To solve this problem, it is proposed to calibrate the constants (factors) included in the functions of thermal engineering calculations by changing them at each calculation stage until the intermediate calculation results match with the data obtained during engineering surveys. The aim of the article authors' is to develop the procedure for thermal engineering calculations, including calculation parameters calibration algorithm. The calculation procedure is described. Design model area grid size and intervals depending on the installation type of the pipeline and operating life of the support structures are specified. Boundary conditions have been established. Necessary and sufficient conditions for input data reliability of the calibration process have been determined.