Robust design of rock slopes with multiple failure modes: modeling uncertainty of estimated parameter statistics with fuzzy number

Changjie Xu, Lei Wang, Yong Ming Tien, Jian Min Chen, C. Hsein Juang

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

The variability of shear characteristics of rock discontinuities is often difficult to ascertain. Thus, even with the reliability-based design (RBD) approach, which allows for consideration of the uncertainty of input parameters, the design of a rock slope system may be either cost-inefficient (overdesign) or unsafe (under-design), depending on whether the variation of input parameters is overestimated or underestimated. The uncertainty about the variation of input parameters is a critical issue in a RBD. This paper presents a feasible approach to addressing this problem using robust design concept. First, the uncertainty of the estimated statistics of input parameters (such as rock properties) is represented by fuzzy sets, which requires only the knowledge of lower and upper bounds of the estimated statistics. Then, the robust design concept is implemented to ensure that the final design is insensitive to, or robust against, the uncertainty of the estimated statistics of input parameters. The design methodology is demonstrated with an application to the design of a rock slope system with multiple failure modes. This design methodology, termed robust geotechnical design (RGD), aims to achieve a certain level of design robustness, in addition to meeting safety and cost requirements. In this paper, the RGD framework is realized through a multi-objective optimization, as it involves three requirements, safety, cost, and robustness. The significance of the design methodology is demonstrated with an example of rock slope design.

Original languageEnglish
Pages (from-to)2957-2969
Number of pages13
JournalEnvironmental Earth Sciences
Volume72
Issue number8
DOIs
StatePublished - 1 Oct 2014

Keywords

  • Failure probability
  • Fuzzy sets
  • Optimization
  • Reliability
  • Robust design
  • Rock slope
  • Uncertainty

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