Quantile framework for simplified geotechnical reliability-based design

Abstract

This paper proposes a quantile-based framework for calibrating reliability-based design factors. The quantile framework is quite versatile: it is applicable to various design formats, such as safety factor design, partial factor design, load and resistance factor design (LRFD), and multiple resistance factor design (MRFD). The advantage of the framework is to allow a single set of design factors to maintain a more uniform reliability over a wider range of design parameters. The proposed framework does not require the capacity to be lumped as a single lognormal random variable as assumed in the LRFD format nor does it require tedious segment by segment optimization of the resistance factors in the MRFD format. The applicability and usefulness of the proposed framework are illustrated using a geotechnical design example. The results show that the proposed approach is able to maintain a uniform reliability over a wide range of design parameters with a single set of design factors. © 2011 ASCE.