关键词: 靠椅状滑坡, 位移阶跃, 变形特征, 滑坡阈值, 八字门滑坡, 三峡库区

Abstract: The evolution history of chair-shaped soil landslide is long and the landslide itself is relatively stable. However, under the influence of periodic rise and fall of water level in the Three Gorges Reservoir, the monitoring deformation curve of this kind landslide shows stepped displacement every year, which seriously affects the early warning and forecast of the landslide. Taking the Bazimen Landslide as an example, combining multi-year field investigation and 15-year monitoring data, the deformation mechanism of the landslide was analyzed and summarized, and the landslide response law was quantitatively analyzed from the perspective of threshold value. The results showed that: ①the statistics of landslide threshold was directly affected by deformation characteristics of this kind landslide. ②through the quantitative analysis on automatic monitoring data, the landslide failure threshold value affected by the reservoir water level declining rate was obtained: stage i,0.2 m/d and lasting about 20 days; stage ii,0.4 m/d and lasting about 30 days.

Key words: chair-shaped soil landslide, stepped displacement, deformation characteristics, landslide failure threshold, Bazimen Landslide, Three Gorges Reservoir area