THE BASIC CHARACTERISTICS AND CAUSES OF LANDSLIDE AT SHANGBA VILLAGE,DAGUAN COUNTY OF YUNNAN PROVINCE

The article is based on field surveyed that Shangba landslide, Daguan county of Yunnan province, analysing of the basic characteristics and causes of the landslide. The landslide was the shape of tongue, lateral widest 230m, vertical longest 380m, the average thickness of the sliding body about 6m, body side slip about 52.44104m3,the whole landslide area can be divided into the overall decline area and traction crack area.(1)The overall decline in area：Length 120m, width 80m, the scarp was long 60m, high 7.5m after falling edge of the area, scarp occurrence 9268,it showed significant shed and stacking that the south side of the sliding body in the falling.(2)Traction crack area：Showed fecal dustpan, the narrow width, the horizontal width of 30meters, 60meters under the horizontal width, 70meters lengthwise. The most notable feature was the crack area formed on the slope of the level of scattered crack scarp and the formation of a crack groove in the north slope. Groove toward 68,lengthwise 20m, horizontal width 3～10m, depth 0.5～3m, with the passage of time, the groove may be further lengthened, widened and deepened under the action of rainfall.Shuanggou homologous geological structure and the negative topography, it provided favorable terrain conditions for the occurrence of landslide. By Yiliang earthquake affected, tensile fractures of abrupt slope provides a natural underpass for rainfall infiltration. Sustained rainfall infiltration, softed the slope surface structure, slope soil shear strength reduction, increased its own weight, decline in component increased, this caused a landslide occurred.