Geological origin and stability evaluation of Siwancun landslide in Luding county

作者：Deng Jianhui^*; Chen Fei; Yin Hu; Gao Mingzhong; Meng Yulin; Huang Runtai

来源：Chinese Journal of Rock Mechanics and Engineering, 2007, 26(10): 1945-1950.

• Dadu river
• Diorite
• ESR method
• Evolution
• Geological investigation
• Limit equilibrium method
• Luding county
• Luding hydropower station
• Origin
• Siwancun landslide
• Slope engineering
• Stability evaluation

Siwancun landslide locates at 1 km downstream of the dam site of Luding Hydropower Station and its stability has great influence on the dam design, construction and operation. In order to evaluate its stability, detailed geological investigation and tests are carried out;geological origin and evolution are analyzed, and a geological structural model is established. The landslide is a high-speed one induced by earthquake dated back to 17.2+2 ka B. R, i.e. the late period of Late Pleistocene by ESR method. The landslide dammed Dadu River experienced at least 3 secondary slides after dam break. The present landslide fills is of broom-shaped, around 700 meters long, 800 meters wide and the maximum depths of 137.62 m. The total volume is about 5.0 ×107m3. Its toe extends into the bed of Dadu River. At its front, the bank slope is steep with a slope of 40°, while the middle and rear parts of the slope are gentle. The slide fills are mainly composed of boulders and granular soils of granite and diorite origin, with good permeability. No deformation is evidenced during site investigation. Three-dimensional stability evaluation is carried out using the strength reduction technique and limit equilibrium method;and the factors of safety are 1.49 and 1.42, respectively. It is shown that the landslide is stable.

• 出版日期2007
• 单位四川大学