TGS geotechnical lecture: Robust geotechnical design-Methodology and applications

In this paper, the authors present the concept of robust geotechnical design, a new design methodology used to make the response of a geotechnical system insensitive to, or robust against, the variation of uncertain geotechnical parameters (called noise factors herein). By carefully adjusting the design parameters (those that can be controlled by the designer), this methodology is realized through a multi-objective optimization, in which all the design requirements such as safety, robustness, and cost are explicitly considered. The results of such optimization are often expressed as a Pareto Front, a collection of optimal designs that collectively define a trade-off relationship between cost and robustness, whereas the safety requirement is met. The Pareto Front enables the engineer to make an informed design decision according to a target cost or robustness. The significance and versatility of new design methodology are illustrated with several geotechnical applications including design of shallow foundations, drilled shafts and braced excavations.