Experience with creation of a modern methodological base for evaluation of the state of lower pools on large-scale hydroprojects

Conclusions

Use of the above-indicated basic positions of a single methodological base for the organization of planimetric surveys of the lower pools of hydroprojects makes it possible to obtain reliable information on their actual conditions, which is required for a safety declaration of the water-development works. Positive experience gained from the complex survey of the lower pools at the Volga-Lenin and Saratov hydroelectric power plants may also find application on other hydroprojects, when it is required to evaluate the condition of the underwater portions of structures.

In adopting solutions concerning repair-restoration work, the causes of scouring and component failures that have occurred in channel stabilization on the basis of study retrospective of the conditions under which drawdown flows are released during operation of the hydroproject, including changes in the relation between the flows and levels in the lower pool, should be analyzed. Results of field investigation of the velocity field on the flow under various operating conditions at a hydroproject, and analysis of hydraulic conditions during the passage of design (basic and verified) flow rates provide the basis for substantiation of the design of repair-restoration work and the development of recommendations for continued service, including rules governing the maneuvering of the gates and spillway structures.