大体积混凝土温度应力与温度控制电子书

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内容简介

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Preface

About the Author

Contents

1 Introduction

1.1 The Significance of Thermal Stress in Mass Concrete

1.2 The Features of Thermal Stresses in Concrete Structures

1.3 The Variation of Temperature and Thermal Stress of Mass Concrete with Time

1.3.1 The Variation of Temperature of Mass Concrete with Time

1.3.2 The Variation of the Thermal Stress in Mass Concrete

1.4 Kinds of Thermal Stress

1.5 Analysis of Thermal Stress of a Massive Concrete Structure

1.6 Thermal Stress—The Cause of Crack

1.7 Technical Measures for Control of Thermal Stress and Prevention of Cracking

1.8 The Experience of the Temperature Control and Crack Prevention of Mass Concrete in the Last 30 Years

2 Conduction of Heat in Mass Concrete, Boundary Conditions,and Methods of Solution

2.1 Differential Equation of Heat Conduction, Initial and Boundary Conditions

2.1.1 Differential Equation of Heat Conduction

2.1.2 Initial Condition

2.1.3 Boundary Conditions

2.1.4 The Approximate Treatment of the Third Kind of Boundary Condition

2.2 Surface Conductance and Computation of Superficial Thermal Insulation

2.2.1 Surface Conductance β

2.2.2 Computation of the Effect of Superficial Thermal Insulation

2.3 Air Temperature

2.3.1 Annual Variation of Air Temperature

2.3.2 Cold Wave

2.4 Temperature Increments due to Sunshine

2.4.1 Sun Radiation on Horizontal Surface

2.4.2 Temperature Increment of the Dam Surface due to Sunshine

2.4.3 Influence of Sunshine on the Temperature of Horizontal Lift Surface

2.5 Estimation of Water Temperature in Reservoir

2.6 Numerical Computation of Water Temperature in Reservoir

2.7 Thermal Properties of Concrete

2.8 Heat of Hydration of Cement and the Adiabatic Temperature Rise of Concrete

2.8.1 Heat of Hydration of Cement

2.8.2 Adiabatic Temperature Rise of Concrete

2.9 Temperature on the Surface of Dam

2.10 The Autogenous Deformation of Concrete

2.11 Semi-Mature Age of Concrete

2.11.1 Method for Determining the Semi-Mature Age of Concrete

2.11.2 Formulas for Computing the Semi-Mature Age of Concrete

2.11.3 Meaning of Semi-Mature Age in Engineering

2.11.4 Example of the Influence of Semi-Mature Age

2.11.5 Measures for Adjusting the Semi-Mature Ages of Concrete

2.11.6 Conclusions

2.12 Deformation of Concrete Caused by Change of Humidity

2.13 Coefficients of Thermal Expansion of Concrete

2.14 Solution of Temperature Field by Finite Difference Method

3 Temperature Field in the Operation Period of a Massive Concrete Structure

3.1 Depth of Influence of the Variation of Exterior Temperature in the Operation Period

3.1.1 Depth of Influence of Variation of Water Temperature

3.1.2 Depth of Influence of Variation of Air Temperature

3.2 Variation of Concrete Temperature from the Beginning of Construction to the Period of Operation

3.3 Steady Temperature Field of Concrete Dams

4 Placing Temperature and Temperature Rise of Concrete Lift due to Hydration Heat of Cement

4.1 Mixing Temperature of Concrete—T0

4.2 The Forming Temperature of Concrete T1

4.3 Placing Temperature of Concrete Tp

4.4 Theoretical Solution of Temperature Rise of Concrete Lift due to Hydration Heat of Cement

4.4.1 Temperature Rise due to Hydration Heat in Concrete Lift with First Kind of Boundary Condition

4.4.2 Temperature Rise due to Hydration Heat in Concrete Lift with Third Kind of Boundary Condition

4.4.3 Temperature Rise due to Hydration Heat with Adiabatic Temperature Rise Expressed by Compound Exponentials

4.5 Theoretical Solution of Temperature Field of Concrete Lift due to Simultaneous Action of Natural Cooling and Pipe Cooling

4.6 Temperature Field in Concrete Lift Computed by Finite Difference Method

4.6.1 Temperature Field in Concrete Lift due to Hydration Heat Computed by Finite Difference Method

4.6.2 Temperature Field due to Hydration Heat in Concrete Lift with Cooling Pipe Computed by Finite Difference Method

4.7 Practical Method for Computing Temperature Field in Construction Period of Concrete Dams

4.7.1 Practical Method for Computing Temperature Field in Concrete Lift without Pipe Cooling

4.7.2 Influence of the Placing Temperature Tp of the New Concrete

4.7.3 Practical Method for Computing Temperature in Concrete Lift without Pipe Cooling

4.7.4 Practical Method for Computing Temperature Field in Concrete Lift with Pipe Cooling

4.7.5 Practical Treatment of Boundary Condition on the Top Surface

5 Natural Cooling of Mass Concrete

5.1 Cooling of Semi-Infinite Solid, Third Kind of Boundary Condition

5.2 Cooling of a Slab with First Kind of Boundary Condition

5.3 Cooling of a Slab with Third Kind of Boundary Condition

5.4 Temperature in a Concrete Slab with Harmonic Surface Temperature

5.4.1 Concrete Slab with Zero Initial Temperature and Harmonic Surface Temperature

5.4.2 Concrete Slab, Initial Temperature T0, Harmonic Surface Temperature

5.5 Temperature in a Slab with Arbitrary External Temperature

5.6 Cooling of Mass Concrete in Two and Three Directions, Theorem of Product

6 Stress-Strain Relation and Analysis of Viscoelastic Stress of Mass Concrete

6.1 Stress-Strain Relation of Concrete

6.1.1 Strain of Concrete due to Constant Stress

6.1.2 Strain of Concrete due to Variable Stress

6.1.3 Modulus of Elasticity and Creep of Concrete

6.1.4 Lateral Strain and Poisson’s Ratio of Concrete

6.2 Stress Relaxation of Concrete

6.2.1 Stress Relaxation of Concrete Subjected to Constant Strain

6.2.2 Method for Computing the Relaxation Coefficient from Creep of Concrete

6.2.3 Formulas for Relaxation Coefficient

6.3 Modulus of Elasticity, Unit Creep, and Relaxation Coefficient of Concrete for Preliminary Analysis

6.4 Two Theorems About the Influence of Creep on the Stresses and Deformations of Concrete Structures

6.5 Classification of Massive Concrete Structures and Method of Analysis

6.6 Method of Equivalent Modulus for Analyzing Stresses in Matured Concrete due to Harmonic Variation of Temperature

7 Thermal Stresses in Fixed Slab or Free Slab

7.1 Thermal Stresses in Fixed Slab

7.1.1 Computation of the Temperature Field

7.1.2 The Elastic Thermal Stress

7.1.3 The Viscoelastic Thermal Stresses

7.1.4 The Thermal Stresses in Fixed Slab Due to Hydration Heat of Cement

7.2 Method for Computing Thermal Stresses in a Free Slab

7.2.1 Elastic Thermal Stress in a Free Slab When the Modulus of Elasticity is Constant

7.2.2 Viscoelastic Thermal Stress in a Free Slab Considering the Influence of Age

7.3 Thermal Stresses in Free Concrete Slab due to Hydration Heat of Cement

7.4 Thermal Stresses in Free Slabs with Periodically Varying Surface Temperature

7.4.1 The Temperature Field

7.4.2 The Viscoelastic Thermal Stresses

7.5 Thermal Stress in Free Slab with Third Kind of Boundary Condition and Periodically Varying Air Temperature

7.6 Thermal Stresses Due to Removing Forms

7.6.1 Stresses Due to Removing Forms of Infinite Slab

7.6.2 Stresses Due to Removing Forms of Semi-infinite Solid

7.6.3 Computing Thermal Stress Due to Removing Forms by Finite Element Method

8 Thermal Stresses in Concrete Beams on Elastic Foundation

8.1 Self-Thermal Stress in a Beam

8.2 Restraint Thermal Stress of Beam on Foundation of Semi-infinite Plane

8.2.1 Nonhomogeneous Beam on Elastic Foundation

8.2.2 Homogeneous Beam on Elastic Foundation

8.3 Restraint Stresses of Beam on Old Concrete Block

8.4 Approximate Analysis of Thermal Stresses in Thin Beam on Half-Plane Foundation

8.5 Thermal Stress on the Lateral Surface of Beam on Elastic Foundation

8.6 Thermal Stresses in Beam on Winkler Foundation

8.6.1 Restraint Stress of Beam in Pure Tension

8.6.2 Restraint Stress of Beam in Pure Bending

8.6.3 Restraint Stresses of Beam in Bending and Tension

8.6.4 Coefficients of Resistance of Foundation

8.6.5 Approximate Method for Beam on Winkler Foundation

8.6.6 Analysis of Effect of Restraint of Soil Foundation

8.7 Thermal Stresses in Beams on Elastic Foundation When Modulus of Elasticity of Concrete Varying with Time

9 Finite Element Method for Computing Temperature Field

9.1 Variational Principle for the Problem of Heat Conduction

9.1.1 Euler’s Equation

9.1.2 Variational Principle of Problem of Heat Conduction

9.2 Discretization of Continuous Body

9.3 Fundamental Equations for Solving Unsteady Temperature Field by FEM

9.4 Two-Dimensional Unsteady Temperature Field, Triangular Elements

9.5 Isoparametric Elements

9.5.1 Two-Dimensional Isoparametric Elements

9.5.2 Three-Dimensional Isoparametric Elements

9.6 Computing Examples of Unsteady Temperature Field

10 Finite Element Method for Computing the Viscoelastic Thermal Stresses of Massive Concrete Structures

10.1 FEM for Computing Elastic Thermal Stresses

10.1.1 Displacements of an Element

10.1.2 Strains of an Element

10.1.3 Stresses of an Element

10.1.4 Nodal Forces and Stiffness Matrix of an Element

10.1.5 Nodal Loads

10.1.6 Equilibrium Equation of Nodes and the Global Stiffness Matrix

10.1.7 Collection of FEM Formulas

10.2 Implicit Method for Solving Viscoelastic Stress-Strain Equation of Mass Concrete

10.2.1 Computing Increment of Strain

10.2.2 Relationship Between Stress Increment and Strain Increment for One-Directional Stress

10.2.3 Relationship Between Stress Increment and Strain Increment for Complex Stress State

10.3 Viscoelastic Thermal Stress Analysis of Concrete Structure

10.4 Compound Element

10.5 Method of Different Time Increments in Different Regions

11 Stresses due to Change of Air Temperature and Superficial Thermal Insulation

11.1 Superficial Thermal Stress due to Linear Variation of Air Temperature During Cold Wave

11.2 Superficial Thermal Insulation, Harmonic Variation of Air Temperature, One-Dimensional Heat Flow

11.2.1 Superficial Thermal Insulation, Daily Variation of Air Temperature, One-Dimensional Heat Flow

11.2.2 Superficial Thermal Insulation for Cold Wave,One-Dimensional Heat Flow

11.2.3 Superficial Thermal Insulation, Temperature Drop in Winter, One-Dimensional Heat Flow

11.3 Superficial Thermal Insulation, Harmonic Variation of Air Temperature, Two-Dimensional Heat Flow

11.3.1 Two-Dimensional Heat Flow, Thermal Insulation for Daily Variation of Air Temperature

11.3.2 Two-Dimensional Heat Flow, Thermal Insulation for Cold Wave

11.3.3 Two-Dimensional Heat Flow, the Superficial Thermal Insulation During Winter

11.4 Thermal Stresses in Concrete Block During Winter and Supercritical Thermal Insulation

11.4.1 Superficial Thermal Stresses During Winter

11.4.2 Computation of Superficial Thermal Insulation

11.4.3 Determining the Thickness of Superficial Thermal Insulation Plate

11.5 Comprehensive Analysis of Effect of Superficial Thermal Insulation for Variation of Air Temperature

11.6 The Necessity of Long Time Thermal Insulation for Important Concrete Surface

11.7 Materials for Superficial Thermal Insulation

11.7.1 Foamed Polystyrene Plate

11.7.2 Foamed Polythene Wadded Quilt

11.7.3 Polyurethane Foamed Coating

11.7.4 Compound Permanent Insulation Plate

11.7.5 Permanent Thermal Insulation and Anti-Seepage Plate

11.7.6 Straw Bag

11.7.7 Sand Layer

11.7.8 Requirements of Thermal Insulation for Different Concrete Surfaces

12 Thermal Stresses in Massive Concrete Blocks

12.1 Thermal Stresses of Concrete Block on Elastic Foundation due to Uniform Cooling

12.1.1 Thermal Stresses of Block on Horizontal Foundation

12.1.2 Danger of Cracking of Thin Block with Long Time of Cooling

12.1.3 Concrete Block on Inclined Foundation

12.2 Influence Lines of Thermal Stress in Concrete Block

12.3 Influence of Height of Cooling Region on Thermal Stresses

12.3.1 Influence of Height of Cooling Region on Elastic Thermal Stresses

12.3.2 Influence of Height of Cooling Region on the Viscoelastic Thermal Stresses

12.4 Influence of Height of Cooling Region on Opening of Contraction Joints

12.5 Two Kinds of Temperature Difference Between Upper and Lower Parts of Block

12.6 Two Principles for Temperature Control and the Allowable Temperature Differences of Mass Concrete on Rock Foundation

12.6.1 Stresses due to Stepwise Temperature Difference

12.6.2 Positive Stepwise Temperature Difference and the First Principle About the Control of Temperature Difference of Concrete on Rock Foundation

12.6.3 Negative Stepwise Temperature Difference and the Second Principle About the Control of Temperature Difference of Concrete on Rock Foundation

12.6.4 Stresses due to Multi-Stepwise Temperature Difference

12.6.5 Viscoelastic Thermal Stresses Simulating Process of Construction of Multilayer Concrete Block on Rock Foundation

12.7 Approximate Formula for Thermal Stress in Concrete Block on Rock Foundation in Construction Period

12.8 Influence of Length of Concrete Block on the Thermal Stress

12.8.1 Influence of Length of Concrete Block on the Thermal Stress due to Temperature Difference Between the Upper and Lower Parts

12.8.2 Influence of Joint Spacing on the Thermal Stress due to Annual Variation of Temperature

12.9 Danger of Cracking due to Over-precooling of Concrete

12.10 Thermal Stresses in Concrete Blocks Standing Side by Side

12.11 Equivalent Temperature Rise due to Self-Weight of Concrete

13 Thermal Stresses in Concrete Gravity Dams

13.1 Thermal Stresses in Gravity Dams due to Restraint of Foundation

13.2 Influence of Longitudinal Joints on Thermal Stress in Gravity Dam

13.3 The Temperatures and Stresses in a Gravity Dam Without Longitudinal Joint

13.4 Gravity Dam with Longitudinal Crack

13.5 Deep Crack on the Upstream Face of Gravity Dam

13.6 Opening of Longitudinal Joint of Gravity Dam in the Period of Operation

13.7 Thermal Stresses of Gravity Dams in Severe Cold Region

13.7.1 Peculiarity of Thermal Stresses of Gravity Dam in Severe Cold Region

13.7.2 Horizontal Cracks and Upstream Face Cracks

13.7.3 Measures for Preventing Cracking of Gravity Dam in Severe Cold Region

13.8 Thermal Stresses due to Heightening of Gravity Dam

13.9 Technical Measures to Reduce the Thermal Stress due to Heightening of Gravity Dam

14 Thermal Stresses in Concrete Arch Dams

14.1 Introduction

14.1.1 Self-Thermal Stresses of Arch Dam

14.1.2 Three Characteristic Temperature Fields in Arch Dam

14.1.3 Temperature Loading on Arch Dams

14.2 Temperature Loading on Arch Dam for Constant Water Level

14.2.1 Formulas for Tm2 and Td2

14.2.2 Physical Meaning of the Equivalent Linear Temperature

14.3 Temperature Loading on Arch Dam for Variable Water Level

14.3.1 Computation of Surface Temperature of Dam for Variable Water Level

14.3.2 Temperature Loading on Arch Dam for Variable Water Level

14.4 Temperature Loadings on Arch Dams in Cold Region with Superficial Thermal Insulation Layer

14.4.1 Tm1 and Td1 for the Annual Mean Temperature Field T1(x)

14.4.2 Exact Solution of Tm2 and Td2 for the Yearly Varying Temperature Field T2(x,T)

14.4.3 Approximate Solution of Tm2 and Td2 for the Yearly Varying Temperature Field T2(x,τ)

14.5 Measures for Reducing Temperature Loadings of Arch Dam

14.5.1 Optimizing Grouting Temperature

14.5.2 Superficial Thermal Insulation

14.6 Temperature Control of RCC Arch Dams

14.6.1 RCC Arch Dams without Transverse Joint

14.6.2 RCC Arch Dam with Transverse Joints

14.7 Observed Thermal Stresses and Deformations of Arch Dams

15 Thermal Stresses in Docks, Locks, and Sluices

15.1 Self-Thermal Stresses in Walls of Docks and Piers of Sluices

15.2 Restraint Stress in the Wall of Dock

15.2.1 General Theory for the Restraint Stress in the Wall of Dock

15.2.2 Computation for Wide Bottom Plate

15.2.3 Computation for Bottom Plate with Moderate Width

15.3 Restraint Stress in the Piers of Sluices

15.4 Restraint Stress in the Wall of Dock or the Pier of Sluice on Narrow Bottom Plate

15.5 Simplified Computing Method

15.5.1 T Beam

15.5.2 Simplified Computation of Thermal Stresses in Dock

15.5.3 Simplified Method for Thermal Stresses in Sluices

15.5.4 Simplified Method for E(y, τ) Varying with Age τ

15.6 Thermal Stresses in a Sluice by FEM

15.6.1 Thermal Stress due to Hydration Heat of Cement in Construction Period

16 Simulation Analysis, Dynamic Temperature Control, Numerical Monitoring, and Model Test of Thermal Stresses in Massive Concrete Structures

16.1 Full Course Simulation Analysis of Concrete Dams

16.2 Dynamic Temperature Control and Decision Support System of Concrete Dam

16.3 Numerical Monitoring of Concrete Dams

16.3.1 The Drawbacks of Instrumental Monitoring

16.3.2 Numerical Monitoring

16.3.3 The Important Functions of Numerical Monitoring

16.4 Model Test of Temperature and Stress Fields of Massive Concrete Structures

17 Pipe Cooling of Mass Concrete

17.1 Introduction

17.2 Plane Temperature Field of Pipe Cooling in Late Stage

17.2.1 Plane Temperature Field of Concrete Cooled by Nonmetal Pipe in Late Stage

17.2.2 Plane Temperature Field of Concrete Cooled by Metal Pipe in Late Stage

17.3 Spatial Temperature Field of Pipe Cooling in Late Stage

17.3.1 Method of Solution of the Spatial Problem of Pipe Cooling

17.3.2 Spatial Cooling of Concrete by Metal Pipe in Late Stage

17.3.3 Spatial Cooling of Concrete by Nonmetal Pipe in Late Stage

17.4 Temperature Field of Pipe Cooling in Early Stage

17.4.1 Plane Problem of Pipe Cooling of Early Stage

17.4.2 Spatial Problem of Pipe Cooling of Late Stage

17.5 Practical Formulas for Pipe Cooling of Mass Concrete

17.5.1 Mean Temperature of Concrete Cylinder with Length L

17.5.2 Mean Temperature of the Cross Section of Concrete Cylinder

17.5.3 Time of Cooling

17.5.4 Formula for Water Temperature

17.6 Equivalent Equation of Heat Conduction Considering Effect of Pipe Cooling

17.6.1 Temperature Variation of Concrete with Insulated Surface and Cooling Pipe

17.6.2 Equivalent Equation of Heat Conduction Considering the Effect of Pipe Cooling

17.7 Theoretical Solution of the Elastocreeping Stresses Due to Pipe Cooling and Self-Restraint

17.7.1 The Elastic Thermal Stress Due to Self-Restraint

17.7.2 The Elastocreeping Thermal Stress Due to Self-Restraint

17.7.3 A Practical Formula for the Elastocreeping Thermal Stress Due to Self-Restraint

17.7.4 Reducing Thermal Stress by Multistage Cooling with Small Temperature Differences—Theoretical Solution

17.7.5 The Elastocreeping Self-Stress Due to Pipe Cooling and Hydration Heat of Cement

17.8 Numerical Analysis of Elastocreeping Self-Thermal Stress of Pipe Cooling

17.8.1 Computing Model

17.8.2 Elastocreeping Stresses in 60 Days Early Pipe Cooling

17.8.3 Elastocreeping Stresses in 20 Days Early Pipe Cooling

17.8.4 Elastocreeping Stresses in Late Pipe Cooling

17.8.5 New Method of Cooling—Multistep Early and Slow Cooling with Small Temperature Differences—Numerical Analysis

17.9 The FEM for Computing Temperatures and Stresses in Pipe Cooled Concrete

17.9.1 Pipe Cooling Temperature Field Solved Directly by FEM

17.9.2 Equivalent FEM for Computing the Temperatures and Stresses in Mass Concrete Block with Cooling Pipe

17.9.3 Comparison Between the Direct Method and the Equivalent Method for Pipe Cooling

17.10 Three Principles for Pipe Cooling

17.11 Research on the Pattern of Early Pipe Cooling

17.12 Research on the Pattern of the Medium and the Late Cooling

17.12.1 The Influence of Temperature Gradient on the Thermal Stress

17.12.2 The Influence of Pipe Spacing on the Thermal Stress

17.12.3 The Influence of the Number of Stages of Pipe Cooling

17.13 Strengthen Cooling by Close Polythene Pipe

17.13.1 Effect of Cooling by Close Pipe

17.13.2 Influence of Cooling of Pipe with Small Spacing on the Thermal Stress

17.13.3 The Principle for Control of Pipe Spacing and Temperature Difference T02Tw

17.14 Advantages and Disadvantages of Pipe Cooling

17.15 Superficial Thermal Insulation of Mass Concrete During Pipe Cooling in Hot Seasons

18 Precooling and Surface Cooling of Mass Concrete

18.1 Introduction

18.2 Getting Aggregates from Underground Gallery

18.3 Mixing with Cooled Water and Ice

18.4 Precooling of Aggregate

18.4.1 Precooling of Aggregate by Water Cooling

18.4.2 Precooling of Aggregate by Air Cooling

18.4.3 Precooling of Aggregate by Mixed Type of Water Spraying and Air Cooling

18.4.4 Precooling of Aggregate by Secondary Air Cooling

18.5 Cooling by Spraying Fog or Flowing Water over Top of the Concrete Block

18.5.1 Spraying Fog over Top of the Concrete Block

18.5.2 Cooling by Flowing Water over Top of the Concrete Block

19 Construction of Dam by MgO Concrete

19.1 MgO Concrete

19.2 Six Peculiarities of MgO Concrete Dams

19.2.1 Difference Between Indoor and Outdoor Expansive Deformation

19.2.2 Time Difference

19.2.3 Regional Difference

19.2.4 Dam Type Difference

19.2.5 Two Kinds of Temperature Difference

19.2.6 Dilatation Source Difference

19.3 The Calculation Model of the Expansive Deformation of MgO Concrete

19.3.1 The Calculation Model of the Expansive Deformation for Test Indoors

19.3.2 The Calculation of the Expansive Deformation of MgO Concrete of Dam Body Outdoors

19.3.3 The Incremental Calculation of the Autogenous Volume Deformation

19.4 The Application of MgO Concrete in Gravity Dams

19.4.1 Conventional Concrete Gravity Dams

19.5 The Application of MgO Concrete in Arch Dams

19.5.1 Arch Dams with Contraction Joints

19.5.2 Arch Dams without Contraction Joints, Time Difference

19.5.3 Example of Application of MgO Concrete, Sanjianghe MgO Concrete Arch Dam

20 Construction of Mass Concrete in Winter

20.1 Problems and Design Principles of Construction of Mass Concrete in Winter

20.1.1 Problems of Construction of Mass Concrete in Winter

20.1.2 Design Principles of Construction of Mass Concrete in Winter

20.2 Technical Measures of Construction of Mass Concrete in Winter

20.3 Calculation of Thermal Insulation of Mass Concrete Construction in Winter

21 Temperature Control of Concrete Dam in Cold Region

21.1 Climate Features of the Cold Region

21.2 Difficulties of Temperature Control of Concrete Dam in Cold Region

21.3 Temperature Control of Concrete Dam in Cold Region

22 Allowable Temperature Difference, Cooling Capacity, Inspection and Treatment of Cracks, and Administration of Temperature Control

22.1 Computational Formula for Concrete Crack Resistance

22.2 Laboratory Test of Crack Resistance of Concrete

22.3 The Difference of Tensile Properties Between Prototype Concrete and Laboratory Testing Sample

22.3.1 Coefficient b1 for Size and Screening Effect

22.3.2 Time Effect Coefficient b2

22.4 Reasonable Value for the Safety Factor of Crack Resistance

22.4.1 Theoretical Safety Factor of Crack Resistance

22.4.2 Practical Safety Factor of Concrete Crack Resistance

22.4.3 Safety Factors for Crack Resistance in Preliminary Design

22.5 Calculation of Allowable Temperature Difference and Ability of Superficial Thermal Insulation of Mass Concrete

22.5.1 General Formula for Allowable Temperature Difference and Superficial Thermal Insulation

22.5.2 Approximate Calculation of Allowable Temperature Difference and Insulation Ability

22.6 The Allowable Temperature Difference Adopted by Practical Concrete Dam Design Specifications

22.6.1 Regulations of Allowable Temperature Difference in Chinese Concrete Dam Design Specifications

22.6.2 The Requirement of Temperature Control in “Design Guideline of Roller Compacted Concrete Dam” of China

22.6.3 Temperature Control Regulation of Concrete Dam by U.S. Bureau of Reclamation and U.S. Army Corps of Engineering

22.6.4 Temperature Control Requirements of Concrete Dam of Russia

22.7 Practical Examples for Temperature Control of Concrete Dams

22.7.1 Laxiwa Arch Dam

22.7.2 Toktogulskaya Gravity Dam

22.7.3 Dworshak Gravity Dam

22.8 Cooling Capacity

22.8.1 Calculation for the Total Cooling Capacity

22.8.2 Cooling Load for Different Cases

22.9 Inspection and Classification of Concrete Cracks

22.9.1 Inspection of Concrete Cracks

22.9.2 Classification of Cracks in Mass Concrete

22.10 Treatment of Concrete Cracks

22.10.1 Harm of Cracks

22.10.2 Environmental Condition of Cracks

22.10.3 Principle of Crack Treatment

22.10.4 Method of Crack Treatment

23 Key Principles for Temperature Control of Mass Concrete

23.1 Selection of the Form of Structure

23.2 Optimization of Concrete Material

23.3 Calculation of Crack Resistance of Concrete

23.4 Control of Temperature Difference of Mass Concrete

23.4.1 Temperature Difference Above Dam Foundation and Temperature Difference Between Upper and Lower Parts of Dam Block

23.4.2 Surface-Interior Temperature Difference

23.4.3 Maximum Temperature of Concrete

23.5 Analysis of Thermal Stress of Mass Concrete

23.5.1 Estimation of Thermal Stress

23.5.2 Primary Calculation of the Temperature Stress

23.5.3 Detailed Calculation of Thermal Stress

23.5.4 Whole Process Simulation Calculation

23.6 Dividing the Dam into Blocks

23.7 Temperature Control of Gravity Dam

23.8 Temperature Control of Arch Dam

23.9 Control of Placing Temperature of Mass Concrete

23.10 Pipe Cooling of Mass Concrete

23.11 Surface Thermal Insulation

23.12 Winter Construction

23.13 Conclusion

Appendix: Unit Conversion

References

Index