Efficient evaluation of run-out distance of slope failure under excavation

The run-out distance (RoD) of slope failure is an important indicator for the quantitative risk assessment of landslides. In recent studies, many attempts have been made to estimate RoD by numerical methods for large deformation analyses (e.g., material point method (MPM)). In spite of the research works, the geotechnical profession is slow to adopt the large deformation analyses to geotechnical design, mainly due to the complex modelling process and large computational effort in the numerical methods. To enable the efficient evaluation of RoD in practice, this note proposes a chart method, referring to the idea of Taylor's stability chart, and focusing on the slopes under excavation. The RoD design charts are established based on the results obtained by MPM, where various slope toe excavation distances are incorporated. The accuracy of the chart method is checked through numerical analyses, and it is found that the proposed chart method can produce accurate RoD estimates with the advantage of efficient computation. The results of this study reveal that the idea of the chart method can be a way to facilitate the application of large deformation analyses in geotechnical design.