Planar sliding is a typical failure mode of dip slops, in which an unstable rock block slides along a weak plane, resulting in a rapid movement. Based on the previous studies, the friction coefficient of the sliding plane varies with the velocity. To reflect the velocity-dependent friction behavior, this study proposes a particulate interface model (PIM) of the particulate DEM to simulate the planar sliding behavior. To validate the performance of the proposed model, the results of a DEM simulation of the planar sliding of a rigid block are compared with the analytical dynamic solution. The results reveal that the PIM simulation is consistent with the analytical dynamic solution with or without consideration of the velocity-dependent friction law. The ordinary contact model does not accurately reflect the theoretical dynamics owing to the high resistance. With respect to the deposition distribution, the different interface models yielded the various velocities before impact, and therefore various failure patterns of the block and appearances of the deposition. The block velocity significantly influences the number of cracks. The results of the analysis reveal that the PIM can capture the planar sliding and deposition behavior of dip slope failure.
Planar sliding is a typical failure mode of landslides, in which an unstable rock block slides along an internal weak plane, resulting in the rapid movement of rocks; it often occurs in cases of dip slope failure, and makes lots of catastrophic disaster. For example, the Tsaoling and Chiufenerhshan regions in Taiwan were destroyed by dip slope failure during the Chi-Chi earthquake in 1999. The influenced range of dip slope failure is larger than other landslide such as circular failure because of the friction of sliding surface is weakening due to high-velocity shearing. Therefore, to develop a method to evaluate the stability and velocity-dependent friction behavior of dip slope failure is essential.
Traditionally, the dip slope stability can be analysis by theory of infinite slope stability, and the influenced area can be evaluated by empirical equation. However, these two methods are difficult to merge together and are also hard to consider the velocity-dependent friction behavior of sliding planes. In recent years, the used of numerical analysis has been widely adopted in the investigation of landslide. However, a method to consider both dip slope stability and velocity-dependent friction behavior is rare.