The article presents the system approach to the stochastic assessment of the probability of failure-free operation (as an indicator of mechanical safety) of structural reinforced concrete elements during installation. The required level of reliability can be provided on all the criteria of limit states separately in the process of installation of the reinforced concrete structural element, but it is not provided when considering the process as a system (in terms of reliability theory). This reflects the advantage of mechanical safety assessment based on the probabilistic approaches rather than on the basis of the limit state method (partial safety factor). The numerical example is shown that with an increase of the coefficient of variation of steel yield strength of the lifting loop to a value of approximately 15 %, the reliability index (probability of failure-free operation) decreases sharply. The procedure of statistical quality control and confidence assessment of statistical parameters is an important component in assessing the probability of failure of the installation of load-bearing structural elements. The formulas are given for calculating the system reliability with incomplete statistical information. The approaches to the reliability calculation under incomplete statistical information based on the possibility theory, fuzzy set theory, Dempster-Schaefer theory of evidence, etc. are of special interest. The ultimate level of failure probability should be calculated individually for each case of installation of the reinforced concrete structures based on the allowable risk value. The presented approaches can be used in a comprehensive assessment of failure-free operation probability of other load-bearing structural elements in the design, manufacture, installation, operation and dismantling stages.
Read in №2 of 2020 year "Stochastic Safety Analysis of the Installation of Reinforced Concrete Structural Elements"
10 фев 2020