Heat consumption for temporary heating of underground stations under construction

Introduction. During construction of underground facilities, architectural, finishing and installation works begin before the completion of the main structures. At that time, there is no permanent heating network connection and therefore temporary heat sources must be used to ensure compliance with the works technology. The lack of specific information about the required capacity of such sources makes it impossible to forecast the financial costs, which is essential for contractors. The purpose of the study is to determine the specific value of heat energy consumption for heating underground stations, construction of which is carried out by open method, depending on different outdoor temperatures, construction completion, depth of station installation, as well as the construction volume of the station. Materials and methods. Heat flows have been calculated by means of mathematical modelling of a stationary thermal regime. Analyses of calculation results and normative data have been performed in accordance with the provisions of probability theory and mathematical statistics. Calculation of coefficients and loads are carried out according to generally accepted equations and laws of heat and mass exchange. Climatic data and material parameters are taken according to current normative documents. Results. The values of specific thermal performance of open-cut metro stations depending on space-planning and design solutions, composition of external envelopes, as well as the stage of construction completion (including the presence or absence of backfill) are calculated. Estimated rate of heat energy consumption for temporary heating of open cut metro station is 3.87 Gcal/(1,000 m 3 · month). Conclusions. Temporary heating norms (amount of heat energy) for open-circuit metro stations have been proposed. Heat costs for ensuring the specified air parameters, referred to a unit volume and required for construction and installation works inside the stations during the heating period, are determined.