Alternative environmental contours for structural reliability analysis

•Alternative methods for estimating environmental contours are proposed.•Utilizing direct Monte Carlo simulations of the environmental parameters.•This approach can be used to account for environmental loads in structural reliability analysis.

This paper presents alternative methods for constructing environmental contours for probabilistic structural reliability analysis of structures exposed to environmental forces such as wind and waves. For such structures, it is important to determine the environmental loads to apply in structural reliability calculations and structural design. The environmental contour concept is an effective, risk-based approach in establishing such design conditions. Traditionally, such contours are established by way of a Rosenblatt transformation from the environmental parameter space to a standard normal space, which introduces uncertainties and may lead to biased results. The proposed alternative approach, however, eliminates the need for such transformations and established environmental contours based on direct Monte Carlo sampling from the joint distribution of the relevant environmental parameters. In this paper, three alternative implementations of the proposed generic approach will be outlined.