巨型古滑坡的地质力学诱因：中国金沙江上游特米事件的启示

Geomechanical triggers of a giant palaeo-landslide: insights from the Temi-event in the upper Jinsha River Basin, China

Xiangrui Huang^1,2 ,Zhuo Chen^1,2,Dakai Xu^1,2 

Abstract: This study employs the discrete element method (DEM) to simulate the dynamic processes of landslides induced by rainfall and earthquakes, with the objective of conducting a com prehensive investigation into the influencing factors, failure mechanis ms, energy transfor mation, and movement characteristics of landslides. The methodology employed involved the construction of a two-dimensional landslide model, which was utilized for simulating the instability process of the Temi landslide under conditions of rainfall and seis mic ac tivity. The primary conclusions of this study are as follows: (1) While both rainfall and seis mic events can lead to landslide instability, earthquakes are the predominant trigger for river-blocking landslides. (2) The Temi landslide event and subsequent damming of the Jinsha River occurred through five stages: seis mic-induced rock mass loosening; rear tension cracking and front shear failure; high-speed sliding; front portion crossing the riverbed and climbing the opposite bank; and finally debris accumulation forming the dam. (3) Energy transformation and dissipation are pivotal in landslide dynamics, with frictional heat being the primary energy dissipation source. (4) The evolution of kinetic energy demonstrates initial stability, a gradual increase during sliding, and an eventual decrease to zero upon cessation. The findings of this study indicate that earthquakes are relatively likely to trigger large river-blocking landslides, and the discrete element method has significant advantages in simulating complex geological phenomena, providing impor tant insights for landslide prediction and disaster prevention in earthquake-prone areas.

Keywords: Seis mic landslide; Rainfall-induced landslide; Palaeo-landslide; Two-dimensional discrete element method; Numerical simulation an alysis MatDEM 

Fig.2 a Remote sensing map of the Temi landslide b Lithology and Landslide Distribution in the Study Area

Fig.3 Cross-sectional profile of the Temi landslide

Fig.5 Linear elastic contact model

Fig.6  Process of Temi landslide deformation and failure: a 1.5 s; b 14.0 s; c 22.0 s; d 36.0 s e 64.0 s f 100.0 s g 120.0 s h 140.0 s f 195.0 s (Rainfall)

Huang X, Chen Z, Xu D. Geomechanical triggers of a giant palaeo-landslide:insights from the Temi-event in the upper Jinsha River Basin, China[J]. Natural Hazards, 2025: 1-24.