Three-dimensional analysis of a deep-seated landslide in central Taiwan

Abstract

The unstable slope, which is located at Lushan, central Taiwan, slid when heavy rainfall occurred in recent decades, posing a threat to a nearby village. Slope stability analysis in three dimensions is more realistic and can advance comprehension of the sliding mechanism. The landslides caused by two heavy rainfall events are simulated in sequence using finite element modeling. The three-dimensional (3D) modeling is established according to the data of extensive investigations, including field reconnaissance, borehole drilling, laboratory experimentation, and monitoring of groundwater tables and displacements. In particular, it requires skills for the generation of a sliding surface and the division of the 3D model. The difference in lithology and a joint set initiated the instability of the slope, forming the fractures on the slope. The sliding surface with greatest depth over 100 m has not yet extended to the lower slope, resulting in greater displacements on the upper and middle slopes than those on the lower slope. The 3D numerical modeling not only reasonably simulates the displacements induced by the rainfall events, but also enables 3D visualization and details of the sliding mechanism. Also, it is capable of revealing the features that cannot be explained in a 2D analysis.

Study on the stability of brown coal batter with opened cracks on Maddingley brown coal mine

“…Benefiting from the rapid development of computer techniques, numerical software with function of three-dimensional (3D) model has become a more powerful tool to investigate slope instability problems. Compared to the 2D model that can only demonstrate horizontal or vertical sections, 3D numerical modelling is able to give more realistic results and conduct more comprehensive analysis of sliding mechanism, especially in such a case with non-uniform resistance distribution [16,17]. In addition, 3D model simulation enables better 3D visualization and details such as estimated sliding volume.…”

“…In addition, 3D model simulation enables better 3D visualization and details such as estimated sliding volume. From [16], their 3D analyses revealed the features that cannot be obtained in 2D analyses; for example, the sliding surface was not symmetric with the steeper portion on the east side, and the displacements around the boundary fractures were somewhat smaller than those in the middle portion. 3D model is more capable of presenting the full geometry and structures inside and outside of a slope, so it can better interpret the correlation between slope stability and its surroundings.…”

A novel hybrid integration model using support vector machines and random subspace for weather-triggered landslide susceptibility assessment in the Wuning area (China)

“…It is also observed that climate change and landslide activities have some significant relationship (Sewell et al, 2015). Some recent studies have revealed that submarine landslides and turbidity currents may become more likely due to future rapid global warming (Chang and Huang, 2015). However, some research have indicated that rapid climate change does not necessarily increase the current activity, and thus do not provide a direct evidence as a primary triggering factor (Clare et al, 2015).…”

Long-Term Monitoring of Slope Movements with Time-Domain Reflectometry Technology in Landslide Areas, Taiwan

“…The bedrock of the slope mass is mainly composed of slate with strikes of cleavage range from N10° to 40°E. The slope is defined as composed of 20-m-thick colluvium near the surface and fresh slate at bottom [24]. The Lushan formation in the area belongs to the attitude of the foliation, which influences the mass rock creep structures of foliated rocks and may experience deformation by potential landslides [25].…”