Quantification of stratigraphic boundary uncertainty from limited boreholes and its effect on slope stability analysis

Due to a limited number of boreholes commonly available in geotechnical practice, the subsurface strata interpreted from borehole data unavoidably contain uncertainty, which can affect the subsequent geotechnical analysis, such as slope stability analysis. This paper proposes an integrated framework to quantify the stratigraphic boundary uncertainty (SBU) from limited borehole data and to investigate its effect on slope stability analysis. The fundamental principles and detail steps of the proposed framework are explained for the SBU quantification and simulation and the subsequent SBU-based slope stability analysis. The framework is illustrated and validated by real data from a real estate project site and a slope site from literature. Then, the effect of borehole number on SBU and slope stability analysis are examined using the framework. Results show that the mean value of factor of safety (FS) of the slope approaches gradually to the real FS value with the increase of borehole number, while the standard deviation of FS decreases as the number of boreholes increases.