The article is considered the wall stability of a steel cylindrical pre-stressed granary, compressed by the friction forces of grain and shell, taking into consideration the influence of the grain internal pressure, its elastic resistance from the inside and the elastic resistance of the pre-stressed shell outside. In this case, the initial and subcritical deflection of the shell is assumed to be axisymmetric, and the loss of the shell stability occurs with the formation of asymmetric deflection. The given solution of the problem allows to determine the magnitude of the critical efforts taking into consideration the influence of the grain internal pressure, its elastic repulsion, the magnitude of the initial deflections and the ratio of shell dimensions.

Keywords: stability calculation, wall stability, prestressing, internal lateral pressure, elastic rebound

The article provides materials for research and assessment of the effect of reservoir hydro-systems on the environment. A detailed analysis of the causes and parameters of the influence of hydroelectric small hydropower stations on the hydrobtological resources of rivers. The results of the study and the assessment of the pollution level of the bottom sediments of the head node of the Kashkhatau HPP are given, which confirmed a slight excess of the permissible concentration level in terms of the content of cadmium and oil products. The main factors influencing the low-pressure reservoirs on the natural environment and on the restoration of fish river resources of small rivers are determined. According to the results of engineering and environmental studies, a comparative characteristic of soil pollution by oil products in relation to the permissible level was established, analyzing the results obtained, it was concluded that the content of oil products in the collected soil samples is within the established standards. A comprehensive assessment of pollution of water resources and soils of coastal water protection zones is given.

Keywords: reservoir waterworks, small hydropower plant, aquatic and biological resources, solid runoff, river pollution, flood waters, background concentrations, heavy metals, hydraulic structures

The paper describes the sele-dangerous zones of the North Caucasus and Kabardino-Balkaria. More detail marked selevye problems of the river Gerhozhansu - the most dangerous river in the regions of SK. The results of the descent of powerful mudflows along the gerhozhansu river in 2000-2017, which had disastrous consequences for the city of Tyrnyauz, are presented. Made a study of the results of years of research the authors conducted in mudflow dangerous rivers of the CBD. Based on field field field studies in the river basin. Gerhozhansu revealed a self-regulating natural mechanism that forms naturally when the mudflow converges the most suitable profile of the transit section of the channel, which ensures the passage of the maximum possible mudflow at minimum energy costs. According to the results of analytical studies of the causes of destruction and the reliability of the work of existing structures and saleprovides antimud slide protection facilities. Developed and proposed more efficient design and technological solutions in designing mud and saleprovides structures combined structures that are protected by patents for inventions and useful models. In conclusion, the main results of the research carried out in the work are noted.

Keywords: mudflow dangerous areas; debris flows; transit station; cone-removal; mud dam; saleprovides tray; conveying ability; antimud slide protection facilities; effective design

In the article an accent is done on the problem of fightagainst erosive processes in the regions of North Caucasus. It is marked that earth of recreational zones is windero dedand broken by economic activity of man. And the ant erosion actions and constructions used at the same time are inefficient, need improvement andecologization. Mountain earth is most subject to water erosion, inconnection with the abundant sinking and flow of the meltedwaters. By results of researches erosive processes on slope lands develop more intensively. The substantiation of the need for more effective erosion control measures. Based on the conducted studies the authors have developed more efficient technical solutions to combat water erosion and restoration of disturbed lands. The most effective designs of ant erosion constructions, author's development are offered. Which was found constructive and technological decisions on construction of erosion control structures of food-grade, biodegradable design to restore the ravines and pits of erosion.

Keywords: erosive process, recreational zone, biopositiv product, antierosion construction, ravine, washout pit

The article presents the analysis and safety assessment of hydraulic structures in the upper-Balkar small hydroelectric power plant. This is done for a project for the suspension and preservation of hydraulic structures Verhnebakansky of a small hydropower plant on the river Cherek in Kabardino Balkar-Balkar Republic. A detailed analysis of causes and factors of external impact of natural and man-made disasters on structures. Determined that most dangerous mountain of the construction site are the physical and geological processes. Established that the level of safety of hydraulic structures Verhnebakansky Small hydropower plant at the time of the survey can be assessed as normal. The values of all controlled parameters do not exceed the established safety criteria. Developed and implemented design solutions for the period of the suspension of construction and the stage of preservation provide strength, stability and safety of structures. Object safe for people and the environment.

Keywords: hydraulic structure, small hydro power plant, free-flow diversion tunnel, a sump, diversion tray, physico-geological processes, risk assessment, hazard ratio, possible crash damage, quantification of risk, negligible risk