Control of the state of the structures at the V. I. Lenin Plyavinsk hydroelectric plant (Latvian SSR)

Abstract

and V. I. BelovaMakeup and Organization of the Control of the State of the Concrete Structures. The makeup and extent of the observations on the structures during their operation were partially determined in the design stage and were finally established during construction and the initial Period of project operation. The observations include control of the seepage regimen, settlements, displacements, stress state of the reinforced-concrete elements, and temperature regimen of the water and the reinforced-concrete elements. During the design, construction, and initial operation stages the observations were conducted by personnel from the Gidroproekt Institute, who installed the controlmeasuring instrumentation (some of the piezometers were installed by the constructors).At the hydraulic shop is a group of nine men in charge of control of the state of the hydraulic structures. This group, headed by a senior engineer, is divided into two specialized groups: 1) one in charge of surveying observations consisting of an engineer, a foreman, and three workers (it carries out also surveying observations on the state of the hydraulic stzuctures at the Kegmnsk hydroelectric plant); 2) one in charge of piezome~ic observations and of observations on the stress state of the structures, made up of an engineer and three workers. The personnel at the hydraulic shop gradually acquired experience with all the observations, thanks to the technical assistance provided by the Gidroproekt Institute. The seepage observations have been conducted since 1967, the observations on the stress state of the reinforced-concrete elements since 1968, and the observations on the settlements and displacements of the structures since 1970. Of special importance in the system of structural control is the period of inundation of the pit and filling of the reservoir. To enhance the reliability of the results of the observations carried out by the shop personnel, it is necessary to complete a set of operation observations during about 1.5 years before the pit is inundated and the head on the structures is increased, which will enable the personnel to acquire sufficient knowledge about the instruments and the observation methods and to become prepared for the work.Makeup of the Control-Measuring Systems. The observations on the seepage regime of the structures are carried out by means of embedded and contact piezometers as well as devices for measuring the flows. Observations are carried out also on the penetration of sand into the deep drainage self-venting wells. A total of 317 piezometers was instaUed in the plant structures,* as follows: at characteristic points along the underground contour of the pow-I! Fig. 1. Flew-measuring tank in overall drainage wells. 1) Metal tank; 2) opening establishing the end of the measurement; 3) opening establishing the initiation of measurement; 4) valve for closing the outlet tube; 5) measuring volume; 6) drainage well. erhouse, 67 piezometers, of which 19 were embedded and 48 were contact types; in the water-holding...