ABSTRACT ACKNOWLEDGEMENTS NOMENCLATURE Chapter 1 Introduction 1.1 Types of Embankment Dam 1.2 Hydraulic Fracturing 1.3 Failure of Teton Dam 1.4 Erosion Damage of Balderhead Dam 1.5 Leakage of Hyttejuvet Dam 1.6 Technical Route of Present Study Chapter 2 Literature Review 2.1 Theories of Hydraulic Fracturing 2.1.1 Theories Based on Circular Cavity Expa ion Theory 2.1.2 Theories Based on Spherical Cavity Expa ion Theory 2.1.3 Theories Based on True Triaxial Stress State Analysis 2.1.4 Empirical Formulas 2.1.5 Theories Based on Fracture Mechanics 2.2 Indoor Experimental Studies on Hydraulic Fracturing 2.3 Field Testing Studies on Hydraulic Fracturing 2.4 Model Testing Studies on Hydraulic Fracturing 2.5 Numerical Simulate on Hydraulic Fracturing 2.6 Summary Chapter 3 Conditio and Mechanisms of Hydraulic Fracturing 3.1 Conditio of Hydraulic Fracturing 3.1.1 Cracks Located at Upstream Face of Core 3.1.2 Low Permeability of Core Soil 3.1.3 Rapid Impounding 3.1.4 U aturated Soil Core 3.2 Mechanical Mechanism of Hydraulic Fracturing 3.3 Summaries and Conclusio Chapter 4 Fracture Toughness and Te ile Strength of Core Soil 4.1 Introduction 4.2 Tested Soil 4.3 Testing Technique on Fracture Toughness 4.3.1 Testing Method 4.3.2 Apparatus 4.3.3 Testing Procedures 4.3.4 Testing Program 4.4 Testing Results on Fracture Toughness 4.4.1 Suitability of Linear Elastic Fracture Mechanics 4.4.2 Influence Facto on Fracture Toughness 4.5 Testing Technique on Te ile Strength 4.5.1 Testing Method and Apparatus 4.5.2 Calculation on Te ile Strength 4.5.3 Testing Procedures 4.5.4 Testing Program 4.6 Testing Results on Te ile Strength 4.6.1 Water Content 4.6.2 Dry De ity 4.6.3 Preco olidation Pressure 4.7 Relatio hip Between Fracture Toughness and Te ile Strength 4.8 Discussion 4.8.1 Soils from References 4.8.2 Rocks from References 4.9 Summaries and Conclusio Chapter 5 Fracture Failure Criterion for Core Soil Under Mixed Mode 5.1 Introduction 5.2 Experimental Technique 5.2.1 Loading Assembly 5.2.2 Calculation Theory 5.2.3 Testing Procedures 5.2.4 Test Program 5.3 Testing Results 5.4 Fracture Failure Criterion 5.5 Summaries and Conclusio Chapter 6 Hydraulic Fracturing Criterion 6.1 Introduction 6.2 Failure Criterion 6.2.1 Simplification of Crack 6.2.2 Criterion 6.3 Cubic Specimen with a Crack 6.3.1 Calculation of KI 6.3.2 Calculation of Kn 6.3.3 Calculation of (Kq-KZn)0.s 6.3.4 Dangerous Crack Angle 6.4 Core with a Tra ve e Crack 6.4.1 Calculation of KI 6.4.2 Calculation of Ku 6.4.3 Calculation of (KZr +KZa )0s 6.4.4 Dangerous Crack Angle 6.5 Core with a Vertical Crack 6.6 Strike-Dip of Crack Spreading Easiest 6.7 Summaries and Conclusio Chapter 7 Numerical Method for Hydraulic Fracturing 7.1 Introduction 7.2 Theoretical Formula 7 2.1 Failure Criterion of Hydraulic Fracturing 7.2.2 Path of the Independent J Integral 7.2.3 Virtual Crack Exte ion Method 7.2.4 Calculation of J Integral 7.3 Numerical Techniques 7.3.1 Virtual Crack Aa 7.3.2 Finite Element Model 7.3.3 Water Pressure Applied on Crack Face 7.3.4 Judgement and Simulation of Hydraulic Fracturing 7.4 Numerical Investigation 7.4.1 Finite Element Model 7.4.2 Virtual Crack Depth Aa 7.4.3 Mechanical Paramete of Crack Material 7.5 Numerical Verification 7.5.1 Mode Crack 7.5.2 Mode ]1 Crack and Mixed Mode Crack 7.6 Summaries and Conclusio Chapter 8 Facto Affecting Hydraulic Fracturing 8.1 Introduction 8.2 Facto Affecting Stress Arching Action 8.2.1 Influence of Material Properties 8.2.2 Influence of Dam Structure 8.3 Relation Between Hydraulic Fracturing and Arching Action 8.4 Facto Affecting Hydraulic Fracturing 8.4.1 Analyzing Method 8.4.2 Influence of Water Level 8.4.3 Influence of Crack Depth 8.4.4 Influence of Crack Position 8.4.5 Influence of Core Soil Features 8.5 Summaries and Conclusio Chapter 9 Simulation on Nuozhadu Dam 9.1 Introduction to Nuozhadu Dam 9.2 Behavior of Stress-Deformation of Nuozhadu Dam 9.2.1 Finite Element Model 9.2.2 Material Paramete 9.2.3 Behavior of Stress-Deformation After Co truction 9.2.4 Behavior of Stress-Deformation After Filling 9.3 Analyzing Method of Hydraulic Fracturing of Nuozhadu Dam 9.3.1 Analyzing Method 9.3.2 Material Paramete 9.3.3 Finite Element Model 9.3.4 Schemes Analyzed 9.4 Hydraulic Fracturing in Horizontal Cracks 9.5 Hydraulic Fracturing in Vertical Cracks 9.6 Summaries and Conclusio References