The main results of the study of hydraulic losses in the suction line and mechanical damages of the impellers of pumps due to cavitation-abrasive wear are given in the article. The scientific task of using theoretical bases for justifying factors affecting the wear rate of pump parts is being solved. On the basis of these theories, a technique is proposed for calculating the wear rate of the elements of the flow-through part of the pumps. During the experimental studies, standard methods of laboratory-bench testing of pumps were used. The operating modes of pumps with minimal wear of their parts are established. Poor hydraulic flow conditions with swirl zones cause an increase in energy losses and a redistribution of flow rates across sections. Wear the parts that are flowing directly proportional to the concentration in the sediment flow, the cube of the flow velocity, the time of action on the pump units. The presence of unsteady vortex regions, especially when the effect of eddy formation increases, leads to fluctuations in the velocities and pulsations of the flow pressure. Cavitation in the pump occurs when the operating modes of the pump differ from the nominal. The increase in volumetric efficiency, the improvement of hydraulic flow conditions to the pump impeller and the reduction of cavitation wear were achieved by the authors in a new pump design that contains guide planes fixed to the throttle plate parallel to the suction nozzle axis with an elastic outer surface. In the same areas of constructive improvement of pump assemblies, it is necessary to search for ways to reduce the negative impact of cavitation and hydroabrasive erosion on the life of pumps.

The aim of the work is to develop a methodology and technique for modeling reinforced soil for further use and application in hydraulic facilities to ensure their stable operation. The objectives of the study are to substantiate the efficiency of using dams of large canals made of reinforced soil at hydraulic structures of pumping stations of the Republic of Uzbekistan, taking into account local conditions, developing recommendations for the rational design of retaining walls and dams from reinforced soil. To achieve this goal, it is necessary to solve the problems of coordinating the operating modes of the pumping station with the introduction of retaining walls and dams from reinforced soil on full-scale structures. The article discusses the implementation of the method of building them in the management of water distribution on irrigation systems in Bukhara and Kashkadarya regions. The theoretical foundations of modeling and design of test stands for the study of volumetric models of dams of large channels made of reinforced soil have been developed. Studies on volumetric models of dams made of reinforced soil were carried out in compliance with the criteria of approximate similarity, which made it possible to obtain new physical ideas about the operation of structures at the stage of destruction. The conducted studies of the models of the built-up part of the dams made it possible to estimate the bearing capacity by the value of the breaking load of the reinforced model to the value of the breaking load of the unreinforced (reference) model. The presence of reinforcement in the soil increases the bearing capacity of the model in comparison with the unreinforced one: even with the volume percentage of reinforcement μ = 0.064%, the hardening coefficient is equal to Chard = 2.60; with μ = 0.032% Chard = 1.70-2.07. With the same percentage of reinforcement μ = 0.032%, an increase in the vertical spacing of the reinforcement leads to a decrease in the bearing capacity by 12-15%. A more even arrangement of reinforcing elements in the ground (close vertical and horizontal spacing between them Sh ≈ Sv ) ensures the maximum bearing capacity of a reinforced soil structure.

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The purpose of the research was to study the hydraulic conditions of the flow supply in the new design of the curved suction pipe and to study the effect of these conditions on the pump operation. Improving the suction pipes provides a predetermined schedule of water supply, reducing unproductive losses and the cost of electricity for water lifting. Therefore, such studies are relevant. The article uses methods of physical modeling with the introduction of the obtained data on full-scale structures. The values of the dimensionless coefficients and the corresponding hydraulic gradients for various times are studied on a suction pipe model at Qmax and Qmin, over the entire range of operating parameters. The chosen method of improving the suction pipes provides an optimal water supply schedule, reducing unproductive losses and electricity costs for water lifting. During the reconstruction of pumping stations, projects for the modernization of water supply facilities were introduced with annual energy efficiency amounting to 1312 million sum for the pumping stations Kuyumazor, Kiziltepa-1 - 105 million sum.