When more than one time-varying load act on a strucutre, the maximum intensity of the combination during the reference peirod needs to be considered. This paper first presents the theoretical expressions of the cumulative distribution function (cdf) of the maximum intensity of the combination. Numerical examples show that the theoretical expression of the cdf provides fairly good estiamte regardless of the statistical characteristics of the load intensity and stochastic processes. To avoid considering time-dependency in determning the design point, it is proposed to consider the intensities of the laod processes at the time when the combination takes its maximum value. The theoretical expression of the processes at the time when the combination takes its maximum value. The theoretical expression of the joint probability density function (pdf) of these intensities is presented. The design point is located as the most likelihood point of the joint pdf on the limit state surface.
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