Irrigation-induced loess flow failure in Heifangtai Platform,North-West China

【作者】 L.Xu； F.C.Dai； Q.M.Gong； L.G.Tham； H.Min；

【Author】 L.Xu F.C.Dai Q.M.Gong L.G.Tham H.Min Institute of Geology and Geophysics, Chinese Academy of Sciences,100029 Beijing,China Beijing University of Technology,100022 Beijing,China Department of Civil Engineering,The University of Hong Kong, Hong Kong,China Institute of Rock and Soil Mechanics, Chinese Academy of Sciences,430071 Wuhan,China

【机构】 Institute of Geology and Geophysics,Chinese Academy of Sciences； Beijing University of Technology； Department of Civil Engineering,The University of Hong Kong； Institute of Rock and Soil Mechanics,Chinese Academy of Sciences；

【摘要】 <正>Because the construction of dams and hydroelectric power stations of Liujiaxia and Yanguoxia across the Yellow River in West Gansu Province,North-West China,inhabitants in the reservoir areas were resettled in Heifangtai Loess Platform.Irrigation thus started in 1968. Perched water table was significantly raised and resulted in many loess flow failures in the past 30 years.This type of landslide was often featured by long runout distance,high speed and recurrence.Laboratory tests along ICU and CSD stress paths were performed.It is shown that the loess has a strong strain-softening behavior and instability can occur in drained condition before undrained liquefaction.The failure mechanism of loess flow can be interpreted as the following process:with increasing perched water table, collapse in loess was first triggered in drained condition and led to undrained loading to adjacent soil in the lower saturated part of me loess platform.Under gravity loading applied by upper dry loess,undrained flow failure mobilized, eventually.更多还原

【Abstract】 Because the construction of dams and hydroelectric power stations of Liujiaxia and Yanguoxia across the Yellow River in West Gansu Province,North-West China,inhabitants in the reservoir areas were resettled in Heifangtai Loess Platform.Irrigation thus started in 1968. Perched water table was significantly raised and resulted in many loess flow failures in the past 30 years.This type of landslide was often featured by long runout distance,high speed and recurrence.Laboratory tests along ICU and CSD stress paths were performed.It is shown that the loess has a strong strain-softening behavior and instability can occur in drained condition before undrained liquefaction.The failure mechanism of loess flow can be interpreted as the following process:with increasing perched water table, collapse in loess was first triggered in drained condition and led to undrained loading to adjacent soil in the lower saturated part of me loess platform.Under gravity loading applied by upper dry loess,undrained flow failure mobilized, eventually.更多还原