Evaluation of the reliability of hydraulic structures: Fid-Bau Portal

Evaluation of the reliability of hydraulic structures

Lyatkher, V. M. / Zolotov, L. A. / Ivashchenko, I. N. / Yancher, V. B.

Conclusions The variability of the characteristics of external effects and parameters of the initial state typical of hydraulic structures determines the prospects of using methods of reliability theory for finding optimal solutions with respect to the design, construction, and operation of hydraulic structures.The current construction standards insufficiently successively realize the probabilistic approaches. The probabilities of deviation of the characteristics of the properties of materials and loads from the average (standard) values and also the probabilities of various combinations of loads and characteristics of materials are taken into consideration in the standards by means of a system of assigned coefficients. Such an approach does not take into account the diversity of real working conditions of hydraulic structures and therefore both an overestimation and underestimation of the necessary reliability of the structure, which is especially essential for large hydraulic structure, are possible.The successive use of the apparatus of reliability theory makes it possible to obtain the most economical design, to avoid unfounded margins and unjustified losses by minimizing the total cost of constructing the structure and loss calculated with consideration of the probability of damages and failures.The reliability evaluation method being developed, the basic principles of which we presented, is aimed precisely at such an approach.Complete realization of methods of reliability theory is not always possible both owing to their insufficient development and as a consequence of the lack of initial information on the statistical characters of the load and properties of the materials and also of data on possible less. In the first stage it is advisable to use simpler methods utilizing, for example, the regulated value of the permissible probability of failures (or damage) during the year established on the basis of generalizing the operating experience of constructed hydraulic structures of various types. It is suggested to consider permissible the annual probability of failure of the most important structure not higher than $ 10^{−5} $−$ 10^{−4} $. As society develops the requirements imposed on reliability will probably increase.It is advisable to use the developed method simultaneously with methods regulated by the existing construction specifications and regulations (SNiP) both for mutual checking and particularly for refining the possible value of the coefficients of SNiP indirectly taking into account the probabilistic character of the phenomena.