Debris flows often occur in landslide deposits during heavy rainstorms.Debris flows are initiated by surface water runoff and unsaturated seepage under rainfall conditions.A physical model based on an infinitely long,...Debris flows often occur in landslide deposits during heavy rainstorms.Debris flows are initiated by surface water runoff and unsaturated seepage under rainfall conditions.A physical model based on an infinitely long,uniform and void-rich sediment layer was applied to analyze the triggering of debris-flow introduced in landslide deposits.To determine the initiation condition for rainfall-induced debris flows,we conducted a surface water runoff and saturated-unsaturated seepage numerical program to model rainfall infiltration and runoff on a slope.This program was combined with physical modeling and stability analysis to make certain the initiation condition for rainfall-introduced debris flows.Taking the landslide deposits at Wenjiagou gully as an example,the initiation conditions for debris flow were computed.The results show that increase height of surface-water runoff and the decrease of saturated sediment shear strength of are the main reasons for triggering debris-flows under heavy rainfall conditions.The debris-flow triggering is affected by the depth of surface-water runoff,the slope saturation and shear strength of the sediment.展开更多
A numerical model is proposed to simulate the unsteady seepage flow through dam, with both saturation and water head as variables to describe the seepage domain. Experiments of seepage flow through dam with unsteady c...A numerical model is proposed to simulate the unsteady seepage flow through dam, with both saturation and water head as variables to describe the seepage domain. Experiments of seepage flow through dam with unsteady conditions were conducted in laboratory to verify the reliability and the accuracy of the numerical model. The performance of the model is also assessed by comparing with analytical solutions. The examples show that the accuracy and the reliability of the model are adequate to handle seepage flow problems with complex conditions. It is also demonstrated that the method of determining the seepage surface through the saturation description is natural, logical and practical in actual applications. The method provides a relatively simple computing scheme, as compared with traditional methods.展开更多
Water-rich slope,which could easily fail after prolonged or heavy rain,is very sensitive to rainfall.Pingyikou Landslide is a typical water-rich slope located in the Three Gorges Reservoir area of China.It was unstabl...Water-rich slope,which could easily fail after prolonged or heavy rain,is very sensitive to rainfall.Pingyikou Landslide is a typical water-rich slope located in the Three Gorges Reservoir area of China.It was unstable because of the continuous rainfall that occurred from September to October 2017.To understand the deformation process and genetic mechanism of the landslide,the geomorphological features,geological characteristics,hydrological conditions,and rainfall characteristics were systematically studied by a detailed field investigation of the slope and monitoring of rainfall,water level,and displacement.In addition,the influence of different initial conditions on the stability of the slope was also studied through numerical simulation using measured rainfall data on the basis of which,the effect of antecedent rainfall on slope stability was studied by unsaturated seepage analysis method.The results show that the deformation of slope is strongly correlated with the rainfall and groundwater level,and this landslide is a typical rainfall-induced landslide.In the analysis of genetic mechanism of the same type of landslide,a maximum initial pore water pressure of -25 kPa as the initial condition is reasonable.And the antecedent rainfall has a greater effect on the stability of the slope,more than 10 days of antecedent rainfall should be considered when designing and controling the slope.展开更多
基金supported by the Key Project of Chinese National Programs for Fundamental Research and Development (Grant No.2011CB409902)the National Natural Science Foundation of China (Grant No.41102194)
文摘Debris flows often occur in landslide deposits during heavy rainstorms.Debris flows are initiated by surface water runoff and unsaturated seepage under rainfall conditions.A physical model based on an infinitely long,uniform and void-rich sediment layer was applied to analyze the triggering of debris-flow introduced in landslide deposits.To determine the initiation condition for rainfall-induced debris flows,we conducted a surface water runoff and saturated-unsaturated seepage numerical program to model rainfall infiltration and runoff on a slope.This program was combined with physical modeling and stability analysis to make certain the initiation condition for rainfall-introduced debris flows.Taking the landslide deposits at Wenjiagou gully as an example,the initiation conditions for debris flow were computed.The results show that increase height of surface-water runoff and the decrease of saturated sediment shear strength of are the main reasons for triggering debris-flows under heavy rainfall conditions.The debris-flow triggering is affected by the depth of surface-water runoff,the slope saturation and shear strength of the sediment.
文摘A numerical model is proposed to simulate the unsteady seepage flow through dam, with both saturation and water head as variables to describe the seepage domain. Experiments of seepage flow through dam with unsteady conditions were conducted in laboratory to verify the reliability and the accuracy of the numerical model. The performance of the model is also assessed by comparing with analytical solutions. The examples show that the accuracy and the reliability of the model are adequate to handle seepage flow problems with complex conditions. It is also demonstrated that the method of determining the seepage surface through the saturation description is natural, logical and practical in actual applications. The method provides a relatively simple computing scheme, as compared with traditional methods.
基金supported by the National Natural Science Foundation of China(Nos.51879245 and 41920104007)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Nos.CUGCJ1821 and CUG1910491T07)the National Overseas Study Fund(No.202106410040).
文摘Water-rich slope,which could easily fail after prolonged or heavy rain,is very sensitive to rainfall.Pingyikou Landslide is a typical water-rich slope located in the Three Gorges Reservoir area of China.It was unstable because of the continuous rainfall that occurred from September to October 2017.To understand the deformation process and genetic mechanism of the landslide,the geomorphological features,geological characteristics,hydrological conditions,and rainfall characteristics were systematically studied by a detailed field investigation of the slope and monitoring of rainfall,water level,and displacement.In addition,the influence of different initial conditions on the stability of the slope was also studied through numerical simulation using measured rainfall data on the basis of which,the effect of antecedent rainfall on slope stability was studied by unsaturated seepage analysis method.The results show that the deformation of slope is strongly correlated with the rainfall and groundwater level,and this landslide is a typical rainfall-induced landslide.In the analysis of genetic mechanism of the same type of landslide,a maximum initial pore water pressure of -25 kPa as the initial condition is reasonable.And the antecedent rainfall has a greater effect on the stability of the slope,more than 10 days of antecedent rainfall should be considered when designing and controling the slope.
