The aim of research is to obtain a calculated dependence for determination of the filtration flow through small damages of concrete in the form of hair cracks, using the experiment planning theory (Greek-Latin square). The reasons for their formation are the aging and destruction of concrete lining, dynamic loads that arise during the operation of structures, the impact of water flow, as well as the temperature drop. All these phenomena lead to the formation of hair cracks which expand from water at negative temperatures in winter season. The gradually expanding cracks increase in height spreading inward and subsequently become through, so an important task is to prevent the formation of through cracks that contribute to the structure destruction as a whole. The studies performed are based on the application of the experiment design theory which took into account 10 independent factors that exert the greatest influence on the filtration flow through the crack. According to the results of the research, a multifactorial semiempirical dependence is obtained, which allows to determine the flow through small, crooked damages (hair cracks), with an acceptable accuracy for preliminary estimates. The adequacy of the theoretical studies carried out is confirmed by the author's verification of the initial factors according to the F-criterion of Fisher, and the significance by the Student's t-criterion. Data processing was performed by the least-squares method using the recommendations and methodology of L. Z. Rumshinsky. The graphs of filtration expenditures obtained in the work show the results of the experiment, and preliminary calculations based on the semiempirical dependence obtained show that the filtration flow through the cracks of the concrete linings is 0.189 square meters per day; the calculations give the result close to that obtained by Yu. M. Kosichenko.
Keywords: experiment planning, Greek-Latin square, the concrete lining, the filtration flow rate, crack, filtration.
