RELIABILITY-ANALYSIS OF CREEP AND SHRINKAGE EFFECTS

This paper deals with the analysis of uncertain creep and shrinkage effects, and in particular the computation of the probability o serviceability failure for a reinforced concrete structure subjected to stochastic loadings. A sustained load of uncertain magnitude, a stationary Gaussian loading process, and a Poisson loading process are considered. To model the creep and shrinkage phenomena. Bazant-Panula model is employed. The resulting time-variant reliability problem is an upcrossing problem in stochastic process theory that is, in general, difficult or computationally demanding to solve. The problem can be simplified to allow prediction at end of a given time period, using the so-called time-independent reliability theory (e.g., the first-order second-moment method). However, this can be achieved only once the statistics of the load effects have been obtained by Monte Carlo simulation, but is considerably less demanding than a complex Monte Carlo solution. A numerical example is given to illustrate the method, and the results are compared with simulation results.