The effect of real records of several earthquakes on polymer pipeline vibrations are studied and analyzed in the paper. Longitudinal vibrations of straight end section of the underground pipeline are considered using the Kelvin-Voigt model. To solve the equation, the method of finite differences of the second order of accuracy is used. An algorithm has been compiled and on its basis a software product has been developed for the numerical calculation of an underground polymer pipeline under the effect of real seismograms recorded in different cities of the world. The stress-strain state (SSS) of polymer pipelines is determined under various boundary conditions.

The article presents the results of the tests on cavitation-abrasive wear of pumps, depending on their operation modes. And also, in the work, the issues of the appearance of cavitation in hydro abrasive flows, which can lead to rather complex phenomena, which presents difficulties for understanding the essence of the process, are considered. To date, the wear of the working bodies of centrifugal and axial pumps, depending on the mode of their operation, has not been sufficiently studied and a methodology for choosing operating modes that takes into account the wear of their parts has not been developed. Also, the work presents the results of comprehensive laboratory and field studies to research the wear rate of the elements of the flowing part of centrifugal and axial pumps. An alternating pulsating load leads to an increase in the force of interaction of the hydro abrasive flow with the surface of the chamber and increases its wear by 10%, and also reduces the productivity of the pump unit to 9%. It is recommended that the operating modes and the geometric height of the suction of the pumps be selected based on cavitation characteristics constructed from erosion tests.

This paper reports on the results obtained the priority recommended strategy for carrying out reconstructive work aimed of the reliability control and safety of Jizzakh main pumping station. It has been established that the safe operation level of Jizzakh main pumping station is supported under the following conditions: The watermark in the pump station forebay are not lower than 314.55 and watermark in the headpond is not higher than 337.80 and not lower than 336.90 for the main units. At the station, no more than 5 “main” and 2 “subsidiary” units work, one “main” unit must be constantly in reserve.

This study is devoted to the assessment of the stress state and dynamic characteristics of various structures. The actual task at the design stage is to determine the parameters of a structure. In this article, a mathematical model was developed for assessing the stress state and dynamic characteristics of plane and spatial structures based on the Lagrange variational equation using the d’Alembert principle. The variational problem for the structures considered by the finite element method leads to the solution of nonhomogeneous algebraic equations or to the solution of algebraic eigenvalue problems. To assess the adequacy of the model and the accuracy of the numerical results obtained, a plane and spatial test problem with an exact solution was solved. Using the proposed model, the eigenfrequencies and modes of oscillations of the gravitational and earth dams (296 m high) of the Nurek reservoir were investigated. At that, it was revealed that in the natural modes of vibration of earth dams, the greatest displacements under low frequencies are observed at the crest part or at the middle of the slopes.