The complex establishing process of numerical model of landslide under three-dimensional condition using discrete element analysis (DEA) was presented. Particle flow code (PFC3D) based on DEA was utilized to explore the numerical landslide models which derived from two different resolutions of digital elevation model (DEM) from real topographical map located in Taiwan. Possible scenario of post-failure of kinematic runout behavior and deposition process of the landslide, considering influenced parameters (i.e. ball friction coefficient and wall friction coefficient, respectively) were also investigated. The constitutive model used was linear parallel bond contact model in which the uniaxial compression test was carried out as the calibration approach to obtain the micro-properties in PFC3D. The construction of landslide model requires two main components, the slip surface (modelled by wall elements) and sliding mass (modelled by ball elements), respectively. Two different DEM resolutions of 5 meters (finer) and 20 meters (coarser) were then carried out to simulate the slip surface. The wall elements of the slip surface generated from finer DEM model were approximately 16 times greater than those in the coarser DEM model. The BFM (brick filling method) logic was also utilized to estimate the capacity of sliding mass. The progressive process of landslide movement showed different behavior during deposition process with the same set real-time for both finer and coarser models. As the results, landslide model with coarser DEM could faster fit the deposition area within 468 seconds than using finer DEM model. A good agreement was shown by smaller wall and ball friction in which this circumstance show that decreasing the wall and ball friction coefficient would result the sliding mass to easily slide down along the slip surface and resulted particles to reach farer position of deposition area. In conclusion, the comprehensive analysis and results suggest that considering finer resolution of DEM model might be conducted in terms of more distributed area required, more realistic and fit the deposition area better compared to real post-event investigation but require longer of computational time. Coarser resolution of DEM model might perform kinematic energy less, less of computational time. However, the selection of which DEM resolution was probably dependent on the how large the investigated area was, considering the affected area, etc. The study demonstrates that a difference of 5M and 20M DEM resolution can be used to investigate the different behavior on kinematic runout and deposition process of the numerical model of landslide together with the influenced parameters also lead to satisfactory agreement with the related studies.

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