Chapter 1 Introduction 1.1 Slope Failures Under Rainfall and Failure Mechanisms 1.2 Recent Advances and Hot Research Topics 1.3 Outline of The Book References Chapter 2 Infiltration and Seepage Analysis in Soil Slopes 2.1 Introduction 2.2 Estimation of Infiltration Rate Based on Conceptual Model 2.2.1 Mechanism of Infiltration in Soils 2.2.2 Green—ampt Model for Infiltration of Constant Rainfall on A Level Ground 2.2.3 Infiltration of Constant Rainfall on A Sloping Ground 2.2.4 Infiltration of Time—varied Rainfall on A Sloping Ground 2.3 Seepage Analysis in Unsaturated Soil Slopes Based on Physical Governing Equation 2.3.1 Governing Equation of Water Flow in Unsaturated Soil 2.3.2 Hydraulic Properties of Unsaturated Soils 2.3.2.1 Soil—water characteristic curve 2.3.2.2 Coefficient of permeability function 2.4 Analytical Solutions of the Richards Equation 2.4.1 Analytical Solution of One—dimensional Infiltration Under Constant Rainfall 2.4.2 Analytical Solution of One—dimensional Infiltration Under Time—varied Rainfall 2.4.3 Effect of Soil Properties，Boundary Conditions，and Initial Conditions 2.4.3.1 Saturated permeability ks 2.4.3.2 Desaturation coefficient asy 2.4.3.3 E／i（ective water content θs—θr 2.4.3.4 Antecedent sur Jhce J Tux q0 2.4.3.5 Rain Jall intensity q1 2.4.3.6 Thickness of soil layer L 2.5 Numerical Analysis of the Richards Equation 2.5.1 Standard Formulations 2.5.2 Spatial Approximation and Time Discretization 2.5.3 Nonlinear Solution Methods 2.5.4 Numerical Oscillation 2.5.5 Rainfall Infiltration Boundary Condition 2.6 Typical Pore—water Pressure Profiles Under Rainfall Condition 2.7 Soil Conditions Under Which Matric Suction Can be Maintained 2.7.1 Pore—water Pressure Profiles Under Steady—state Conditions 2.7.2 Pore—water Pressure Profiles Under Transient Seepage Conditions 2.7.2.1 Effect of air—entry value on the wetting front 2.7.2.2 Effect of the saturated coefficient of permeability 2.7.2.3 Influence of water storage coefficient 2.7.2.4 Effect of the groundwater boundary conditions 2.7.3 Geotechnical Engineering Implications References Chapter 3 Stability Analysis of Slope Under Rainfall Infiltration Based on Limit Equilibrium 3.1 Introduction 3.2 Infinite—slope Stability Analysis Based on One—dimensional Infiltration Profile 3.2.1 General Equation of Factor of Safety for Infinite Unsaturated Slope 3.2.2 Simplified Scenarios of Various Seepage Conditions 3.2.2.1 Steady—state condition with seepage parallel slope surface 3.2.2.2 Transient condition with different shapes of wetting front 3.2.3 Slope Stability Based on Estimated Nonlinear Unsaturated Shear Strength 3.2.3.1 Fredlund et al.（1996）nonlinear shear strength equation 3.2.3.2 Vanapalli et al.（1996）nonlinear shear strength equation 3.2.3.3 Vilar（2006）nonlinear shear strength equation 3.2.3.4 Khalili and Khabbaz（1998）nonlinear shear strength equation 3.2.3.5 Bao et al.（1998）nonlinear shear strength equation 3.3 Slope Stability Analysis Based on Limit Equilibrium Methods 3.4 Controlling Factors for Rainfall—induced Landslides 3.4.1 Soil Shear Strength Properties 3.4.2 SoiIHydraulic Properties 3.4.3 Rainfall Characteristics 3.5 Spatially Distributed Model of Hazard Assessment of Rainfall—induced Landslides 3.5.1 General Methodology 3.5.2 Performance Index References Chapter 4 Coupled Hydromechanical Analysis for Unsaturated Soil Slope 4.1 Introduction 4.2 Modeling of Unsaturated Soil Based on Continuity Mechanics 4.2.1 State Variables 4.2.2 Governing Equations 4.2.2.1 Force equilibrium 4.2.2.2 Mass continuity of water phase 4.2.3 Formulations Based on Elastic Constitutive Model 4.2.3.1 Ef fective stress approach 4.2.3.2 Two stress state variables approach 4.2.4 Illustrative Examples for Elastic Model 4.2.4.1 ConsoLidation o f unsaturated soil 4.2.4.2 Heave o f ground under evaporation 4.2.5 Formulations Based on Plastic Constitutive Models 4.3 Slope Stability Analysis Based on，Coupted Modeling 4.3.1 Stress Analysis 4.3.1.1 Simpli fied approach 4.3.1.2 Fully coupled approach 4.3.2 Estimation of Factor of Safety for Slope Stability 4.4 Illustrative Examples 4.4.1 A Simple Slope Example Based on Elastoplastic Model and Effective Stress Concept 4.4.2 Case Study of 1976 Sau Mau Ping Landslide 4.4.2.1 FEmodel 4.4.2.2 Soil properties 4.4.2.3 Resultsand discussion 4.4.3 Case Study of A Field Test of Rainfall—induced Landslide 4.4.3.1 Site description 4.4.3.2 Erperiment procedure 4.4.3.3 Numerical modeL 4.4.3.4 Soil properties 4.4.3.5 Results and Discussion References Chapter 5 Stability of Soil Slope with Cracks 5.1 Introduction 5.2 Prediction of Unsaturated Hydraulic Functions of Cracked Soil 5.2.1 Pore Size Distribution of Cracked Soil 5.2.2 Prediction of SWCC for Desiccation Crack Networks 5.2.2.1 A general method to estimate SWCC based on the capillary law 5.2.2.2 SWCC for soil matrir with known pore—size distribution 5.2.2.3 Water retention curve for cracks 5.2.3 Prediction of SWCC for Nondeformable Cracked Soil 5.2.4 Prediction of Tensorial Permeability Function for Nondeformable Cracked Soil 5.2.4.1 Saturated permeability o f desiccation cracks 5.2.4.2 Permeability function for desiccation cracks 5.2.4.3 Prediction o f permeabiLity function for cracked soil 5.2.5 Hysteresis Models for SWCC and Permeability Function 5.2.6 Prediction of SWCC and Permeability Function Considering Crack Volume Change 5.2.6.1 Desiccation induced crack volume change 5.2.6.2 SWCC and permeability function jor cracked soil considering crack volume change 5.3 Example 5.3.1 Prediction of SWCC and Permeability Function for Cracked Soils Considering Crack Volume Change 5.3.2 Parametric Study and Discussions 5.4 Stability of Soil Slope with Cracks 5.4.1 Methodology 5.4.2 Results References Chapter 6 Stability Analysis of Colluvium Slopes Upon A Rainstorm 6.1 Introduction 6.2 Hydraulic Properties of'Colluvial Soils 6.3 Shear Srrength of Colluvial Soils 6.4 An Example 6.4.1 Methodology 6.4.2 Seepage Analysis Results 6.4.2.1 Slopescomposed of soils With high fines fractions 6.4.2.2 Slopes composed of colluuial soils with high coarse fractions 6.4.3 Stability Analysis Results References …… Chapter 7 Reliability Analysis of Slope Under Rainfall Chapter 8 Probabilistic Assessment of Randomly Heterogeneous Soil Slopes Chapter 9 Probabilistic Model Calibration Index
