Slope reliability analysis using the geotechnical random field method

Abstract

Inherent soil variability, measurement errors and transformation uncertainty are the three primary geotechnical uncertainties. Random field theory (RFT) is the most versatile and practical tool utilised in reliability analyses. RFT has conventionally been considered to model the inherent variability, with other geotechnical uncertainty sources usually ignored, although some degree of measurement error is incorporated in geotechnical test measurements. In addition, RFT induces a series of non-geotechnical uncertainties during simulation, including correlation function errors and uncertainty in statistical parameters. In this paper, a geotechnical random field algorithm is introduced for the evaluation of slope reliability considering different geotechnical uncertainty sources. Accordingly, a drained c–ϕ slope was considered for reliability analysis considering geotechnical uncertainties. It was shown that, by adding measurement error and transformation uncertainty to the inherent variability, the probability of failure is noticeably increased. Slope reliability analyses using the algorithm proved to give conservative results in comparison with approximate, stationary and non-stationary stochastic methods in the face of inherent soil variability.