ABSTRACT
After the accumulation slope above the left bank intake of Xiluodu Hydro-electrical Power Station is excavated, it has been discovered by drill-monitoring that there exist obvious deformations at the deepseated of the slope. Xiluodu Hydro-electrical Power Station is being built on the middle-lower reaches of JinSha River near Yongshan city, Yunnan. There exists huge accumulation platform above base rock along the valley abutment of the left bank. In the area of the slope, the deposits are mainly composed of diluvium, glacial-fluvial deposits and ancient landslide sediments from top to bottom. The surface deformation occurred after first time cutting. Penetrative tensile-cracks and slip cliff appeared near the upper of the excavation slope. The deformation-time curves show that the sheardeformation decreases gradually in rate. The rate of shear deformation is from 0.12 mm/d to 0.25 mm/d. The deep-seated deformation is obviously characterized by stable creep. The deformation is practically a kind of deformationadjustment accompanied by stress re-distribution during cutting.
