ABSTRACT
No. 1 landslide is located at the area from the east of Er Lang mountain to the upper of TianQuan river, on which the river valley is deep, the landform steep, the rainfall plentiful and the bush grows thickly. The factors resulting in No. 1 landslide can be summarized as follows: the downcutting of LongDan rivulet leading to the slump of mountain body, the existence of old landslides, and the revivifying of old landslides under the influence of rainstorm and mud-rock flow. A lot of experts have studied the mechanism of landslide in different aspects which involve variation of pore water pressure, the creep law of slide slip layer, the failure mode and staged causes of landslide and so on. Data from drilling and deep displacement monitoring have confirmed that there are both several slide surfaces in eastern and western landslides.
