Abstract
In reliability-based limit state design, the performance level of a structure can be controlled by differentiating load and resistance factors. In order to take fully the advantage, Draft Recommendation of Limit State Design by AIJ proposes a practical method for evaluating the factors. This paper investigates its accuracy and applicability using numerical examples. It was found that a large error could be observed, depending on the statistical characteristics of load intensities, due to mainly improper approximation of non-lognormal random variable to lognormal. An improved method for the approximation is proposed taking the target reliability level into account.
