PROBABILISTIC ASSESSMENT OF THE RELIABILITY OF PASSIVE

Abstract

. The introduction of probabilistic methods for assessing the reliability of building structures is governed by modern design standards. When constructing engineering facilities, the task is to construct the structural elements using passive anchors. This work is aimed at creating and testing an algorithm of probabilistic assessment of passive anchors, which determines its relevance. The work’s objective is to develop an algorithm of probabilistic assessment of the reliability of passive anchors by the criteria of loss of reliability, which are possible during the operation of the anchor– concrete system, taking into account the random nature of the material properties and load. The input deterministic parameters of the algorithm were: basic anchorage length; a cross-sectional area of the anchor; Poisson’s ratio of concrete; concrete modulus of elasticity. Random inputs were: axial tensile strength and compression strength; tensile resistance of rebar; axial and shear forces. The calculation is performed by the method of statistical tests N times. The number of tests, in which the rod is considered unreliable, refers to the total number of tests and determines the risk for the steel anchor of reaching its boundary conditions for its entire service life, followed by calculation of the annual risk for the anchor of reaching its boundary conditions. According to the results of probabilistic calculations, the risk for the anchor of reaching its boundary conditions for the assigned service life is Р = 1.87 10 -2 year -1 , the annual risk for the anchor of reaching its boundary conditions is Р r = 3.77 10 -4 year -1 , which does not exceed its permissible value of Р і ех = 5 10 -4 year -1 , provided for by the design standards for structures of CC2 consequences (responsibility) class for the estimated lifetime of T ef = 50 years.