COMBINATION OF CORRELATED LOAD EFFECTS AND STRUCTURAL RELIABILITY ANALYSIS

The reliability of structure is related to the extreme values of loads acting on the structure during its lifetime. But it is rare that all the loads reach their maxima simultaneously. Thus, from economical point of view, load effect combination should be made in structural design. Most relevant studies assume that the load effects are mutually independent. But it is not true in some situation, for the load effects may be correlated because of the influence of common random sources. The present paper reveals that the practical load combination rules, such as Turkstra rule, cannot be used directly to cope with this problem. With the clustering characteristics of correlated loads and the introduction of an equivalent effect of the loads, an approach for the combination correlated load effects is developed. Illustrative examples show that the correlation between the load effects has a great influence on the reliability of structure. It is necessary to consider the correlation of load effects in design.