相关荷载效应组合及结构可靠度计算

相关性是孪生性荷载的基本特征之一。本文研究了相关荷载效应的组合问题，通过引入一个综合了相关荷载效应特性的等效荷载效应，提出了基于Ｔｕｒｋｓｔｒａ规则的荷载效应实用组合方法，并给出相关荷载效应组合和可靠度分析的算例。算例分析表明，荷载效应的相关性对结构的可靠度有一定的影响，在有条件的情况下应于以考虑。

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.