Reliability Comparative Analysis of Codes for the Design of Cantilever Sheet Pile Walls: Basis for Studying the Principles of International Standards

In geotechnical engineering, the design of cantilever sheet pile walls is one of the most important and complex tasks due to the use of different limit equilibrium design methodologies to estimate the depth of embedment. In some countries, official codes do not fully cover cantilever sheet pile wall design, so designers tend to adopt foreign codes and manuals generally calibrated to the local conditions. In this paper, the performance of several combinations of limit equilibrium design methodologies from international codes and manuals are evaluated using a proposed multiphase Monte Carlo simulation-based probabilistic design procedure. The results show that the direct implication of the safety factors and soil/wall friction on D/H is related to a significant change of the relative degree of conservatism of codes and manual design methodologies from high to small probability levels. It is found that even when the results of several codes and manuals methodologies agree, their implementation does not produce a design with a low risk of failure, especially for those methodologies that involve the European limit state design (LSD) approach. It is evidenced that for methodologies with unfactored passive pressures, the uncertainty in the response may not be calculated in a mechanically consistent way through reliability analysis. Finally, it is determined that the effect of soil variability in the depth of embedment is not linear when an increment of uncertainty is incorporated into the design, especially for the design combination constituted by the Hansen method and the North American LSD approach.