Normally,the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes.In this study,the limit stress state and discrimination equation of an ...Normally,the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes.In this study,the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion.Therefore,a novel failure mode involving three sliding zones(upper tension zone,middle shear sliding zone,and lower compression zone)was proposed.Accordingly,based on the limit equilibrium analysis,a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established.Subsequently,the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software.The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods,and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage.Finally,an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study.The results show that the infinite slope tends to be conservative because the edge effect is neglected,particularly when the ratio of surficial slope length to depth is relatively small.展开更多
From the continuum mechanics perspective, an attempt was made to clarify the role of Terzaghi's effective stress in the theoretical analysis of saturated soil subjected to seepage. The necessity of performing a co...From the continuum mechanics perspective, an attempt was made to clarify the role of Terzaghi's effective stress in the theoretical analysis of saturated soil subjected to seepage. The necessity of performing a coupled hydromechanical analysis to solve the seepage-deformation interaction problem was illustrated by examining the equations of static equilibrium among the effective stress, seepage force, pore-water pressure and total stress. The conceptual definition of stress variable that satisfies the principles of continuum mechanics is applied in the coupled hydromechanical analysis. It is shown that Terzaghi's effective stress is in fact not a stress variable under seepage conditions, and the seepage force acting on the soil skeleton cannot be viewed as a body force. This offers a clue to the underlying cause of a paradox between the real Pascal's hydrostatic state and the hydrostatic state predicted by a class of continuum hydromechanical theories.展开更多
基金This research was supported by the Sichuan Science and Technology Program(No.2019YJ0323)the National Natural Science Foundation of China(Grant No.42007247).
文摘Normally,the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes.In this study,the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion.Therefore,a novel failure mode involving three sliding zones(upper tension zone,middle shear sliding zone,and lower compression zone)was proposed.Accordingly,based on the limit equilibrium analysis,a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established.Subsequently,the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software.The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods,and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage.Finally,an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study.The results show that the infinite slope tends to be conservative because the edge effect is neglected,particularly when the ratio of surficial slope length to depth is relatively small.
基金Project(51278171)supported by the National Natural Science Foundation of ChinaProject(B13024)supported by the"111"Project,China+1 种基金Projects(2014B04914,2011B02814,2010B28114)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(617608)supported by the Research Grants Council of the Hong Kong Special Administrative Region of China
文摘From the continuum mechanics perspective, an attempt was made to clarify the role of Terzaghi's effective stress in the theoretical analysis of saturated soil subjected to seepage. The necessity of performing a coupled hydromechanical analysis to solve the seepage-deformation interaction problem was illustrated by examining the equations of static equilibrium among the effective stress, seepage force, pore-water pressure and total stress. The conceptual definition of stress variable that satisfies the principles of continuum mechanics is applied in the coupled hydromechanical analysis. It is shown that Terzaghi's effective stress is in fact not a stress variable under seepage conditions, and the seepage force acting on the soil skeleton cannot be viewed as a body force. This offers a clue to the underlying cause of a paradox between the real Pascal's hydrostatic state and the hydrostatic state predicted by a class of continuum hydromechanical theories.
