PROCEDURE OF PROBABILISTIC STRENGTH ASSESSMENT OF MONOLITHIC REINFORCED CONCRETE LINIGS OF HIGH-PRESSURE HYDROTECHNICAL TUNNELS OF HPP AND PSPP DURING THE OPERATIONAL PERIOD

Abstract

In the article, a methodology for the probabilistic assessment of the strength of monolithic reinforced concrete lining of hydraulic pressure tunnels of HPPs and PSPs during the operational period has been developed within the theory of complex technical systems reliability. Based on the analysis of the available deterministic solution to the problem of stresses in the working annular reinforcement for the considered lining, the coupling equation necessary for solving the probabilistic problem is obtained. The dividing of the parameters included in the coupling equation into random and nonrandom (deterministic) is justified. Recommendations for the selection of distribution functions types, as well as the parameters of these functions for random variables included in the obtained coupling equation are given. An algorithm for solving the posed probabilistic problem by the Monte Carlo method is proposed. Recommendations on the selection of the of statistical tests number that provide sufficient accuracy of the calculation results are given. Based on the proposed algorithm, Ukrhydroproject PJSC developed a software As a result of this software operation, the calculated probability of the tunnel lining destruction at the end of the estimated operating life, as well as the annual probability of the tunnel lining destruction, can be obtained. The calculations of the probability of destruction of the reinforced concrete lining of the supplying high-pressure tunnel of the Dniester PSP are carried out. The following results were obtained the probability of destruction of the lining of the tunnel during the estimated service life 2.42ˑ10-4 and the annual probability of destruction of the tunnel lining is 0.24ˑ10 -5 1/year.