Abstract:On October 10 and November 3, 2018, the Baige landslide blocked the Jinsha River twice, causing huge damage to the downstream. There are still three large-scale residual deformation bodies K1, K2, and K3 around the previous sliding source area, which may be slide and block the river again. Restricted by the natural geological conditions of the landslide area, there is little research work on the residual Baige landslide, which cannot provide support for the risk management of the Jinsha River hydropower project construction. Based on the topographic survey, deformation measurement, and deep structure detection in the deformation area, the volume, destabilization mode, and possible sliding combinations of the three residual bodies were analyzed. The scale of the unstable body entering the river was evaluated on the basis of scraping effect, motion trajectory, loose factor, etc. Based on the current valley topographic data, the previous barrier body morphology analysis and PFC3D software simulation, the future barrier body parameters were predicted for different sliding modes. The results showed that the volume of three unstable areas reached 159.3×10⁴ m³, 460×10⁴ m³, and 142×10⁴ m³ respectively; there were three types of destabilization in the residual body of Baige landslide, namely, the small-scale collapse, the large-scale unloading deformation, and the sliding; the possible and the most dangerous combination was that the four sub-zones 1–4, 2–1, 3–1, and 3–2 slide at the same time with the volume of 271×10⁴ m³; under different sliding conditions of the deformable rock, the maximum height of barrier body was 47.5 m with the ground elevation 2 937.5 m when sliding along the main chute into the river, and 28.7 m with the ground elevation 2 923.7 m when sliding along the upstream slope of the Baige landslide groove.