This paper presents the preliminary idea for the “effective random dimension” (d’), which quantifies the equivalent number of random variables that significantly affect the variability of the limit state (G) of concern. It is shown through simple examples that there might be a nearly unique relationship between d' and the quantile position (η) required to achieve a prescribed reliability level. This conference paper only presents the basic idea of this new concept of d’. The detailed study of this new concept will be presented elsewhere.
Keywords: Effective random dimension, Reliability-based design, Reliability analysis, QVM.