Methods of Surveying the Inlet and Outlet Channels of the Spillway Dam at the Hydroelectric Power Plant

Abstract

The paper deals with methods of the hydroacoustic survey of the outlet, inlet channels of the spillway dam at the Zhigulevskaya hydroelectric power plant and waters adjacent to the earth-fill dam. The survey of underwater parts of hydraulic structures and the bottom of the Zhigulevskaya hydroelectric power plant was carried out with the help of the hydroacoustic method and included full coverage of all surfaces of underwater parts. All deformations of the surveyed surfaces and all foreign objects on them, the size of which exceeded 0.5 m in height, were recorded. The survey of the waters was carried out with tacks of basic coverage based on a system of parallel tacks oriented in parallel and perpendicular to the axis of the structures. The devices used for the survey allowed obtaining coordinate increments in the plan and along the height at the distances of the surveyed waters with an accuracy of not more than 0.1 m and a confidence coefficient of 95 %. When performing the set of works, it became possible to conduct the hydroacoustic survey and create a bathyorographical map for the inlet and outlet channels at the spillway dam. The hydroacoustic survey allowed making a sample-based assessment of the condition of concrete slopes of the outlet, inlet channels at the spillway dam, of the HPP as well as the condition of slope protection at the earth-fill dam in the waters of the upper pool. The analysis of the survey results helped to evaluate the dynamics of the deformation process taking place at the bottom of the outlet, inlet channels at the spillway dam, the HPP and in the waters around the earth-fill dam. As a result, measures for the operational reliability of structural elements in the outlet, inlet channels at the spillway dam, the HPP and in the waters around the earth-fill dam were developed. In addition, according to the results of the hydroacoustic survey of the outlet, inlet channels at the spillway dam of the Zhigulevskaya HPP, a new bathymetrical map was created.