正版 碾压混凝土动态力学特性及本构模型研究

Contents

1 Constitutive Relations of RCC: An Overview 1

1.1 Background 1

1.2 Literature Review 3

1.2.1 Dynamic Behaviors and Constitutive Models for Normal Concrete 3

1.2.2 Special Physical and Mechanical Properties of RCC 4

1.2.3 Size-Dependence of Concrete Under Dynamic Loads 6

1.2.4 Aggregate Effect on Mechanical Behaviors of Concrete 8

References 11

2 Experimental Research on Dynamic Behaviors of RCC 17

2.1 Introduction 17

2.2 Experimental Procedures 18

2.2.1 Material and RCC Mix Proportion 18

2.2.2 Specimen Preparation 21

2.2.3 Quasi-static Testing Results 22

2.2.4 Reliability Analysis of SHPB Test 23

2.3 Effect of Construction Technique on Dynamic Behaviors 26

2.3.1 Dynamic Mechanical Properties 26

2.3.2 Stratification Effect of RCC on Dynamic Mechanical Properties 29

2.4 Shock Wave Propagation Across Interlayers in RCC 31

2.4.1 Experimental Scheme 31

2.4.2 Incident and Transmitted Waveforms 33

2.4.3 Reflection and Transmission of Shock Wave Propagation 34

2.5 Theoretical Analysis on the Shock Wave Propagation 36

2.5.1 Wave Propagation in Viscoelastic Medium 36

2.5.2 Wave Attenuation During Propagation Across RCC 38

2.5.3 Influence of Interlayers on Transmitted Wave 41

2.6 Summary and Conclusions 42

References 43

3 Meso-mechanic-Based Dynamic Behaviors of RCC 47

3.1 Introduction 47

3.2 Mesoscopic Simulation Method and Validation 47

3.2.1 Meso-simulation Method 47

3.2.2 The Constitutive Model and Parameters of Meso-components 50

3.2.3 Validation of Numerical Model 53

3.3 Effect of Maximum Aggregate Size on Dynamic Mechanical Properties of RCC 55

3.3.1 Two Dimensional Mesoscopic Model 56

3.3.2 Effect of Aggregate Size on Dynamic Compressive Behaviors 57

3.3.3 Effect of Aggregate Size on Dynamic Tensile Behaviors 58

3.4 Influence of Layer Effect on Dynamic Mechanical Properties 61

3.4.1 The Influence of Layer Effect on Dynamic Compressive Properties 61

3.4.2 Effect of Layer Effect on Dynamic Tensile Mechanical Properties 62

3.5 Summary and Conclusions 63

References 64

4 Consturction-Induced Damage Effect on Dynamic Compressive Behaviors of RCC 67

4.1 Introduction 67

4.2 Specimen Preparation and Damage Quantification 68

4.2.1 Specimen Preparation 68

4.2.2 Quantification of the Initial Damage 69

4.3 Initial Damage Effect on the Dynamic Behaviors of RCC 71

4.3.1 Mechanical Tests 71

4.3.2 Initial Damage Effect on Stress- Strain Curves 72

4.3.3 Initial Damage Effect on Dynamic Mechanical Properties 73

4.3.4 Statistical Characteristics of Dynamic Compressive Behaviors 73

4.4 Assessment to the Initial Damage Effect on the Dynamic Behaviors 76

4.4.1 Correlation Between Initial Damage and Dynamic Behaviors 76

4.4.2 Evaluation on the Initial Damage from Improper Construction 78

4.5 Summary and Conclusions 80

References 81

3 Size-Dependence of Dynamic Behaviors for RCC Under High-Strain-Rate Loadings 83

3.1 Introduction 83

3.2 Dynamic Size Effect on Experimental Results 84

3.2.1 Schematic Design 84

3.2.2 Failure Patterns 85

3.2.3 Stress-Strain Curves 86

3.2.4 Dynamic Increase Factor for Compressive Stress 87

3.3 Dynamic Size Effect on Compressive Behaviors of RCC 88

3.3.1 Definitions of Dynamic Mechanical Properties 88

3.3.2 Size Effect on Various Dynamic Mechanical Properties 89

3.3.3 Statistical Significance of the Dynamic Size Effect 90

3.3.4 Distribution Characteristic of Dynamic Compressive Strength 91

3.4 Modified Weibull Size Effect Law 95

3.5 Summary and Conclusions 98

References 98

4 Fragmentation-Based Dynamic Size Effect of RCC Under Impact Loadings 101

4.1 Introduction 101

4.2 Fragment Characteristics of RCC Under Impact Loads 102

4.2.1 Dynamic Fragmentation Process 102

4.2.2 Fragment Size Distribution 104

4.2.3 Relationship Between Fragment Size and Dynamic Behaviors 107

4.3 Dynamic Size Effect Depicted by Fractal Characteristics 110

4.4 Fractal Mechanism of Dynamic Size Effect 113

4.5 Summary and Conclusions 116

References 117

5 Dynamic Constitutive Model of RCC for Fully-Graded Dam 119

5.1 Introduction 119

5.2 Strength Surface Modification of Fully-Graded RCC 119

5.2.1 Experimental Study on RCC Triaxial Compression Behaviors 120

5.2.2 Meso-simulation of Triaxial Compressive Behavior of Fully-Graded RCC 124

5.2.3 Strength Surface Modification for RCC Constitutive Model 127

5.3 True Strain-Rate Effect Model of Fully-Graded RCC 128

5.3.1 True Strain-Rate Effect Decoupling Method 128

5.3.2 True Strain-Rate Effect on Dynamic Compressive Strength of RCC 130

5.3.3 True Strain-Rate Effect on Dynamic Tensile Strength of RCC 132

5.3.4 Distribution Characteristic of Dynamic Compressive Strength 91

5.4 Modified Weibull Size Effect Law 95

5.5 Summary and Conclusions 98

References 98

6 Fragmentation-Based Dynamic Size Effect of RCC Under Impact Loadings 101

6.1 Introduction 101

6.2 Fragment Characteristics of RCC Under Impact Loads 102

6.2.1 Dynamic Fragmentation Process 102

6.2.2 Fragment Size Distribution 104

6.2.3 Relationship Between Fragment Size and Dynamic Behaviors 107

6.3 Dynamic Size Effect Depicted by Fractal Characteristics 110

6.4 Fractal Mechanism of Dynamic Size Effect 113

6.5 Summary and Conclusions 116

References 117

7 Dynamic Constitutive Model of RCC for Fully-Graded Dam 119

7.1 Introduction 119

7.2 Strength Surface Modification of Fully-Graded RCC 119

7.2.1 Experimental Study on RCC Triaxial Compression Behaviors 120

7.2.2 Meso-simulation of Triaxial Compressive Behavior of Fully-Graded RCC 124

7.2.3 Strength Surface Modification for RCC Constitutive Model 127

7.3 True Strain-Rate Effect Model of Fully-Graded RCC 128

7.3.1 True Strain-Rate Effect Decoupling Method 128

7.3.2 True Strain-Rate Effect on Dynamic Compressive Strength of RCC 130

7.3.3 True Strain-Rate Effect on Dynamic Tensile Strength of RCC 132

7.4 Modification of the Damage Equation in the K&C Model 135

7.5 Validation of Modified Full-Graded RCC Constitutive Model 137

7.5.1 Validation of Modified K&C Constitutive Model with Single Element Method 137

7.5.2Applicability of Modified K&C Constitutive Model in Slab Subjected to Air Explosion 138

7.6 Summary and Conclusions 140

References 142

在各种基础设施中，高坝在电力、灌溉、防洪等方面具有巨大的政治和经济效益，爆炸袭击下大坝造成严重伤害、财产损失和经济破坏。因此，如何准确模拟碾压混凝土重力坝抗爆性能是一个迫切需要研究的领域。为了揭示混凝土重力坝在水下爆炸作用下的动力响应和破坏机理，本文首先研究了碾压混凝土的动力特性，特别是施工工艺中的垂直分层、层间效应对冲击波传播的影响以及不当碾压造成的初始损伤。然后在全面了解碾压混凝土应变率敏感性和尺寸依赖性的基础上，研究了碾压混凝土的动态尺寸效应。最后，建立适用于水工碾压混凝土材料的动态本构模型，以便对混凝土重力坝的抗爆性进行更合理的评估。