Coupled Characterization of Stratigraphic and Geo-Properties Uncertainties and Evaluation of the Influences on Geotechnical Performance

Theprimary purpose of site characterization is to characterize the subsurface stratigraphic configuration and the associated geo-properties. Due to the inherent spatial variability of geological bodies and limited site investigation efforts, uncertainty is often unavoidable in the derived subsurface stratigraphic configuration and the associated geo-properties. In previous studies, substantial research has been undertaken to address geo-properties uncertainty and evaluate its effects on the performance and design of geotechnical systems. In contrast, characterization of the stratigraphic uncertainty and analyses of its impact on the predicted performance of geotechnical systems have been relatively limited. Further, the literature has hardly reported the studies on a coupled characterization of stratigraphic and geo-properties uncertainties. The authors have recently developed a conditional random field approach for the coupled characterization of stratigraphic and geo-properties uncertainties to fill this technology gap. In thiscoupled approach, the spatial correlation of the stratum existence between different subsurface elements and that of geo-properties are captured by two independent autocorrelation functions; and, the coupling between the stratigraphic configuration and the spatial distributionof geo-properties is realizedby updating the autocorrelation matrix and statistics of geo-properties in non-borehole elements based on the sampledstratigraphic configuration. This paper reviews the key components of the coupled characterization approach, including methodology and implementation procedure.Then, the effectiveness of this characterization approach is demonstrated through a series of examples, and the superiorities over the existing characterization approaches are discussed. Finally, case studies are undertaken to examine the influences of the stratigraphic and geo-properties uncertainties on the geotechnical performanceevaluation.

Keywords: Site Characterization, Stratigraphic Uncertainty, Geo-properties Uncertainty, Random Field, Geotechnical Performance.