一、引言 工程结构构件或截面的安全度(即承载能力的可靠度)的研究,近年来已得到了迅速发展,但多着重于安全指标β的计算,用来校核已知构件的安全度,而另一方面的问题,即按照可以接受的失效概率P_f或安全指标β直接设计结构构件的截面的研究还进行 I. INTRODUCTION The study of the safety of structural members or sections of the engineering structure (ie, the reliability of bearing capacity) has been rapidly developed in recent years, but focuses on the calculation of the safety index β to check the safety of known components. On the other hand, the study of directly designing the cross section of the structural member according to the acceptable failure probability P_f or the safety index β is also conducted.