OPTIMIZATION OF GROUND WATER CUTOFF WITH A SIPHON INTAKE FROM THE DRAIN WELLS (AS IN THE CASE OF KAMYANKA-DNIPROVSKA GROUND WATER CUT-OFF)

Relevance of research.To increase the efficiency and reliability of the territory protection against flooding with the infiltration water of the Kakhovsky Reservoir, it is proposed to replace the low-performance ground water cutoff with an airlift water intake system for the protection of the Kamensky Pod's area with a groundwater cutoff with a siphon intake system from wells. That will enable to increasesignificantly the efficiency and reliability of the ground water cutoff and greatly reduce the specific costs of water pumping. The reliability of the ground water cutoff with a siphon intake system is achieved by ensuring the reliable sealing of the entire siphon collecting conduit. In case of a slightest damage, there is a loss of sealing of the pipes and the water stops flowing into a drain well. The purpose of the research. To determine the best parameters of ground water cutoff with a siphon intake system from the well, in particular: - the optimal number of wells, the distance between them; - estimated depths of each wells connected to the siphon collecting conduit; - estimated water flows from each well and the decrease in the static water table in them taking into account the hydro-geological interaction between them during their collaboration; - optimal pipe diameters on each section of the siphon collecting conduit to ensure the reliability of its operation. The research methods. The research involves the use of analytical and mathematical methods, in particular: calculations, iterations, forecasting. The research results. New approaches enabling to find an optimal variant of uniform water drawdown in the aquifer along the whole length of the siphon water conduit by reducing the depths of the intake wells towards the intake well. To optimize the ground water cutoff with the siphon intake system from the wells, it is proposed to drill drain wells of different depths and place them at different distances from each other along the entire length of the collecting conduit, determining the required depth of the well depending on its diameters and vacuum value. The conducted studies as in the case of calculating the Kamyanka-Dniprovskaground water cutoff showed that the minimum depth of drainage wells depends on the diameter of the well and the vacuum value in it, and the most efficient option of all possible ones is the option when there are drain wells with different depths and they are located at different distances from each other that provides a minimum specific cost for the construction of wells and siphon collecting water conduit.