ANALYSIS OF RANDOM BUCKLING BEARING CAPACITY OF SUPER-LARGE COOLING TOWERS CONSIDERING THE VARIATION OF THE PROPERTY OF CONCRETE

Based on the formal solutions of the buckling eigen equation, the probability density evolution equation for the random buckling eigenvalue is derived. By assuming that the elastic modulus of concrete follows normal and logarithm normal distributions respectively, the probability density function (PDF), mean, standard deviation and reliability of the buckling bearing capacity for a super-large cooling tower are analyzed. The results indicate that the mean buckling bearing capacity based on normal assumption is very close to the one with the deterministic parameter, and its variation is the same as the elastic modulus of concrete. For the logarithm normal assumption, however, the PDF of buckling bearing capacity deviates normal distribution, while the corresponding mean and variation increase but the reliability decreases. The safety factor for the overall buckling of cooling towers required in the design standard is relatively conservative.