TR-20-36_Blast Loaded Connections Design Guidance_2023-02-17.pdf

© 2023 Karagozian & Case, Inc.

TR-20-36

DESIGN GUIDANCE FOR BLAST

LOADED STRUCTURAL

CONNECTIONS

Mark Weaver, S.E.

Eric Kjolsing, S.E., Ph.D.

Pedram Hesam, Ph.D.

Brian Dunn, S.E.

Joseph Magallanes, S.E.

February 17, 2023

Prepared for:

Department of State, Bureau of Diplomatic Security, Physical

Security Division, Research and Development Branch

Attn: Daniel Duke / Alec Williamson

1400 Wilson Blvd.

Arlington, VA 22209

K&C Job No. 200427

Karagozian & Case, Inc.

700 N. Brand Blvd, Suite 700

Glendale, CA 91203-3215

818-240-1919 www.kcse.com i

ACKNOWLEDGEMENTS

The work shown in this report was funded through an award by the Department of State

Bureau of Diplomatic Security.

The authors appreciate the input and ongoing guidance during the development of this document from the Department of State Bureau of Diplomatic Security and the Blast Connection

Research Council.

Mr. Robert Conway, Naval Facilities Engineering and Expeditionary Warfare Center

Dr. Daniel Duke, Department of State Bureau of Diplomatic Security

Dr. Bradley Foust, U.S. Army Engineer Research and Development Center

Ms. Sharon Gallant, KPFF

Mr. John Geringer, U.S. Army Corps of Engineers Protective Design Center

Mr. David Goode, DJ Goode & Associates Ltd

Dr. Matthew Hoehler, National Institute of Standards and Technology

Ms. Andra Hoermann-Gast, Chair of ACI Committee 355

Dr. Charles Ishee, Air Force Civil Engineer Center

Mr. Larry Kruth, American Institute of Steel Construction

Mr. Chris LaVine, Simpson Strong-Tie

Mr. Michael Lowak, BakerRisk

Mr. David McQuaid, D. L. McQuaid and Associates, Inc.

Dr. Clay Naito, Lehigh University

Mr. Lee Nelson, Defense Threat Reduction Agency

Dr. Charles Oswald, AG&E Structural Engenuity

Ms. Vanessa Pickerd, Defence Science and Technology Group

Mr. Andy Remson, Department of State Overseas Building Operations

Mr. Chris Shoemaker, Department of State Overseas Building Operations

Mr. Jonathan Shull, Black & Veatch

Dr. Lauren Stewart, Georgia Institute of Technology

Mr. Alec Williamson, Department of State Bureau of Diplomatic Security ii

EXECUTIVE SUMMARY

Current design guidance for blast loaded connections is typically general in nature, does not distinguish between limit state type, and relies on limit state capacity equations from building codes developed to address serviceability considerations. Additionally, idealized single degree of freedom analytical models with simplified boundary conditions, which are commonly used to design blast-resistant members, can grossly overestimate or underestimate the design reactions for critical connection elements when the blast loading is large or nonuniformly applied. Given the general design guidance offered by blast protection standards and the relative uncertainty surrounding the design reactions for blast loaded connections, it is important to understand the actual capacity and deformation characteristics of potential limit states under dynamic loading conditions. Such an understanding should enable an engineer to safely and reliably design blast loaded connections to respond in a ductile manner even in the event design reactions are underestimated.

This report documents the response phenomenology of known limit states for blast loaded connections. Blast loaded connections of concern include concrete anchorage; bolt, stud, and threaded rod; and welded connections. Specifically, this report documents past testing efforts that undergird the current limit state capacity equations presented in building codes as well as rate effects testing efforts in which failure according to these limit states was observed. Based on this information, limit state capacity equations for blast loading conditions are proposed. The basis for these equations, including the static increase factors and dynamic increase factors that are referenced therein, are summarized in the report that follows.

The proposed modifications to building code limit state capacity equations given in this report represent an initial attempt at design guidance for blast loaded connections. However, as expressed within the body of this report, there are many gaps in the literature related to blast loaded connections. As these gaps are investigated further, it is likely that the proposed modifications given in this report will need to be modified.

iii

TABLE OF CONTENTS

ACKNOWLEDGEMENTS ........................................................................................................ i

EXECUTIVE SUMMARY ........................................................................................................ ii

TABLE OF CONTENTS .......................................................................................................... iii

LIST OF FIGURES ................................................................................................................. xii

LIST OF TABLES .................................................................................................................. xvi

LIST OF ACRONYMS ........................................................................................................ xviii

LIST OF VARIABLES ........................................................................................................... xxi

CHAPTER 1 INTRODUCTION ............................................................................................ 1-1

1.1 Background .......................................................................................................... 1-1

1.2 Objectives ............................................................................................................ 1-1

1.3 Scope and Limitations.......................................................................................... 1-2

1.4 Overview of Connection Design Guidance in Current Blast Protection

Standards .............................................................................................................. 1-2

1.4.1 UFC 3-340-02 .......................................................................................... 1-2

1.4.2 ASCE/SEI 59 ........................................................................................... 1-4

1.4.3 AISC Design Guide 26 ............................................................................ 1-5

1.4.4 ACI 370 .................................................................................................... 1-6

1.4.5 Summary .................................................................................................. 1-7

1.5 Proposed Approach to Designing Blast Loaded Structural Connections ............ 1-7

1.5.1 Design Philosophy ................................................................................... 1-8

1.5.2 Design Reactions ..................................................................................... 1-9

1.5.3 Limit State Strength ............................................................................... 1-16

1.5.4 Deformation Compatibility .................................................................... 1-18

1.6 Gap Analysis and Mitigation Strategies ............................................................ 1-19

1.6.1 Gap 1A: Correlating Material Strain Rates with Load Rates on

Connection Elements ............................................................................. 1-19

1.6.2 Gap 1B: Determining Loading and/or Strain Rates on Connection

Elements due to Blast Loading .............................................................. 1-20

1.6.3 Gap 1C: Validated and Accepted Analytical Method to Rapidly

Compute Design Reactions at Blast Loaded Connections ..................... 1-20 iv

1.6.4 Gap 1D: Consistent, Reliable, and Verifiable Experimental

Techniques to Measure Dynamic Reactions at Connection

Elements ................................................................................................. 1-21

1.7 Report Outline .................................................................................................... 1-21

1.7.1 Workflow Oriented Outline ................................................................... 1-21

1.7.2 Chapter Oriented Outline ....................................................................... 1-23

CHAPTER 2 CONCRETE ANCHORAGE OVERVIEW ..................................................... 2-1

2.1 Scope .................................................................................................................... 2-1

2.1.1 Concrete Type .......................................................................................... 2-1

2.1.2 Anchorage Type ....................................................................................... 2-1

2.2 Concrete Anchorage Characteristics .................................................................... 2-2

2.2.1 Load Resistance Mechanisms .................................................................. 2-2

2.2.2 Code Overview ........................................................................................ 2-4

2.2.3 Limit State Overview ............................................................................... 2-5

2.2.4 Average Expected Dynamic Material Strengths for Concrete

Anchorage ................................................................................................ 2-6

CHAPTER 3 CONCRETE BREAKOUT (TENSION) .......................................................... 3-1

3.1 Background .......................................................................................................... 3-1

3.2 Governing Code Equation .................................................................................... 3-1

3.3 Test Data .............................................................................................................. 3-2

3.3.1 Testing Used to Derive Code Equation ................................................... 3-2

3.3.2 Rate Effects Testing ................................................................................. 3-4

3.3.3 Other Testing ......................................................................................... 3-14

3.4 Proposed Modifications to Limit State Capacity Equations .............................. 3-17

3.5 Gap Analysis and Mitigation Strategies ............................................................ 3-20

3.5.1 Gap 3A: Group Effects Response in Tension Under Blast-Induced

Strain Rates ............................................................................................ 3-21

3.5.2 Gap 3B: Effectiveness of Reinforcement on the Face of Concrete to Bridge Over a Concrete Breakout Failure ......................................... 3-21

3.5.3 Gap 3C: Effectiveness of Anchor Reinforcement for Tensile Load

Under Blast-Induced Strain Rates .......................................................... 3-21

CHAPTER 4 ANCHOR PULLOUT ...................................................................................... 4-1

4.1 Background .......................................................................................................... 4-1

4.2 Governing Code Equation .................................................................................... 4-2 v

4.3 Test Data .............................................................................................................. 4-3

4.3.1 Testing Used to Derive Code Equation ................................................... 4-3

4.3.2 Rate Effects Testing ................................................................................. 4-4

4.4 Proposed Modifications to Limit State Capacity Equations ................................ 4-5

4.5 Gap Analysis and Mitigation Strategies .............................................................. 4-8

4.5.1 Gap 4A: Shock-Qualified Post-Installed Anchor Options and

Literature .................................................................................................. 4-8

4.5.2 Gap 4B: Validation of an Overstrength Factor for Pullout Under

Blast Loading ........................................................................................... 4-8

4.5.3 Gap 4C: Pullout Capacity for Large Embedment Depth Anchorage at Blast-Induced Strain Rates ................................................................... 4-9

CHAPTER 5 CONCRETE SIDE-FACE BLOWOUT ........................................................... 5-1

5.1 Background .......................................................................................................... 5-1

5.2 Governing Code Equation .................................................................................... 5-2

5.3 Test Data .............................................................................................................. 5-2

5.3.1 Testing Used to Derive Code Equation ................................................... 5-2

5.3.2 Rate Effects Testing ................................................................................. 5-4

5.4 Proposed Modifications to Limit State Capacity Equations ................................ 5-4

5.5 Gap Analysis and Mitigation Strategies .............................................................. 5-4

5.5.1 Gap 5A: Pullout Capacity at Large Embedment Depths Near an

Edge at Blast-Induced Strain Rates .......................................................... 5-4

CHAPTER 6 ADHESIVE BOND .......................................................................................... 6-1

6.1 Background .......................................................................................................... 6-1

6.2 Governing Code Equation .................................................................................... 6-3

6.3 Test Data .............................................................................................................. 6-3

6.3.1 Testing Used to Derive Code Equation ................................................... 6-3

6.3.2 Rate Effects Testing ................................................................................. 6-4

6.4 Proposed Modifications to Limit State Capacity Equations ................................ 6-7

6.5 Gap Analysis and Mitigation Strategies .............................................................. 6-9

6.5.1 Gap 6A: Strain Rate Increase for Common Adhesive Anchors .............. 6-9

CHAPTER 7 CONCRETE BREAKOUT (SHEAR) .............................................................. 7-1

7.1 Background .......................................................................................................... 7-1

7.2 Governing Code Equation .................................................................................... 7-1

7.3 Test Data .............................................................................................................. 7-2 vi

7.3.1 Testing Used to Derive Code Equation ................................................... 7-2

7.3.2 Rate Effects Testing ................................................................................. 7-4

7.4 Proposed Modifications to Limit State Capacity Equations ................................ 7-8

7.5 Gap Analysis and Mitigation Strategies ............................................................ 7-10

7.5.1 Gap 7A: Group Effects Response in Shear Under Blast-Induced

Strain Rates ............................................................................................ 7-10

7.5.2 Gap 7B: Effectiveness of Anchor Reinforcement for Shear Load

Under Blast-Induced Strain Rates .......................................................... 7-11

CHAPTER 8 CONCRETE PRYOUT .................................................................................... 8-1

8.1 Background .......................................................................................................... 8-1

8.2 Governing Code Equation .................................................................................... 8-1

8.3 Test Data .............................................................................................................. 8-1

8.3.1 Testing Used to Derive Code Equation ................................................... 8-1

8.3.2 Rate Effects Testing ................................................................................. 8-3

8.4 Proposed Modifications to Limit State Capacity Equations ................................ 8-4

8.5 Gap Analysis and Mitigation Strategies .............................................................. 8-5

8.5.1 Gap 8A: Pryout at Blast-Induced Strain Rates ........................................ 8-5

CHAPTER 9 INTERACTION OF TENSION AND SHEAR FOR CONCRETE

ANCHORAGE ............................................................................................................ 9-1

9.1 Background .......................................................................................................... 9-1

9.2 Governing Code Equation .................................................................................... 9-1

9.3 Test Data .............................................................................................................. 9-1

9.3.1 Testing Used to Derive Code Equation ................................................... 9-1

9.3.2 Rate Effects Testing ................................................................................. 9-2

9.4 Proposed Modifications to Limit State Capacity Equations ................................ 9-2

9.5 Gap Analysis and Mitigation Strategies .............................................................. 9-3

9.5.1 Gap 9A: Group Effects Response in Combined Tension and Shear

Under Blast-Induced Strain Rates ............................................................ 9-3

CHAPTER 10 BOLT, STUD, AND THREADED ROD CONNECTION OVERVIEW .... 10-1

10.1 Scope .................................................................................................................. 10-1

10.2 Limit State Overview ......................................................................................... 10-4

10.2.1 Average Expected Dynamic Material Strengths for BSTR

Connections............................................................................................ 10-5

CHAPTER 11 BOLT, STUD, OR THREADED ROD TENSILE RUPTURE .................... 11-1

vii

11.1 Background ........................................................................................................ 11-1

11.2 Governing Code Equation .................................................................................. 11-1

11.2.1 BSTR Element Rupture ......................................................................... 11-1

11.2.2 BSTR Element or Nut Thread Stripping ................................................ 11-2

11.3 Test Data ............................................................................................................ 11-3

11.3.1 Testing Used to Derive Code Equation ................................................. 11-3

11.3.2 Rate Effects Testing ............................................................................... 11-4

11.3.3 Other Testing ......................................................................................... 11-7

11.4 Proposed Modifications to Limit State Capacity Equations .............................. 11-9

11.5 Gap Analysis and Mitigation Strategies ............................................................ 11-9

11.5.1 Gap 11A: Tensile Response of High-Strength BSTR Elements

Under Blast-Induced Strain Rates ........................................................ 11-10

11.5.2 Gap 11B: Average Expected Strengths for Common Threaded

Rod, Anchor Rod, and Stud Specifications ......................................... 11-10

11.5.3 Gap 11C: Blast Testing Involving BSTR Elements Placed in

Tension ................................................................................................. 11-10

11.5.4 Gap 11D: Criteria to Prevent Thread Stripping Under Blast-

Induced Strain Rates ............................................................................ 11-11

CHAPTER 12 BOLT, STUD, OR THREADED ROD SHEAR RUPTURE ....................... 12-1

12.1 Background ........................................................................................................ 12-1

12.2 Governing Code Equation .................................................................................. 12-1

12.3 Test Data ............................................................................................................ 12-2

12.3.1 Testing Used to Derive Code Equation ................................................. 12-2

12.3.2 Rate Effects Testing ............................................................................... 12-3

12.3.3 Additional Rate Effects Testing ............................................................. 12-8

12.4 Proposed Modifications to Limit State Capacity Equations .............................. 12-9

12.5 Gap Analysis and Mitigation Strategies ............................................................ 12-9

12.5.1 Gap 12A: Shear Response of Common High Strength Bolts Under

Blast-Induced Strain Rates ..................................................................... 12-9

12.5.2 Gap 12B: Average Expected Strengths for Common Threaded

Rod, Anchor Rod, and Stud Specifications ......................................... 12-10

12.5.3 Gap 12C: Blast Testing Involving BSTR Elements Placed in Shear ... 12-10

CHAPTER 13 BOLT, STUD, OR THREADED ROD BENDING ..................................... 13-1

13.1 Background ........................................................................................................ 13-1 viii

13.2 Governing Code Equation .................................................................................. 13-1

13.3 Test Data ............................................................................................................ 13-1

13.3.1 Testing Used to Derive Code Equation ................................................. 13-1

13.3.2 Rate Effects Testing................................................................................ 13-3

13.4 Proposed Modifications to Limit State Capacity Equations .............................. 13-4

13.5 Gap Analysis and Mitigation Strategies ............................................................ 13-4

13.5.1 Gap 13A: Bending Response of BSTR Elements to Blast-Induced

Strain Rates ............................................................................................ 13-4

13.5.2 Gap 13B: Bolt Bending Limit State Equation for BSTR Elements

That Do Not Have a Defined Yield Stress ............................................. 13-5

CHAPTER 14 INTERACTION OF TENSION AND SHEAR FOR BOLTS, STUDS,

OR THREADED RODS ........................................................................................... 14-1

14.1 Background ........................................................................................................ 14-1

14.2 Governing Code Equation .................................................................................. 14-1

14.3 Test Data ............................................................................................................ 14-2

14.3.1 Testing Used to Derive Code Equation ................................................. 14-2

14.3.2 Rate Effects Testing ............................................................................... 14-4

14.4 Proposed Modifications to Limit State Capacity Equations .............................. 14-4

14.5 Gap Analysis and Mitigation Strategies ............................................................ 14-4

14.5.1 Gap 14A: Confirmation that the Elliptical Failure Surface is

Accurate for BSTR Elements Placed in Combined Tension and

Shear Due to Blast Loading ................................................................... 14-5

14.5.2 Gap 14B: Reduction of Headed Stud Capacity When Placed Under

Combined Tension and Shear Due to Blast Loading ............................. 14-5

CHAPTER 15 BOLT HOLE BEARING .............................................................................. 15-1

15.1 Background ........................................................................................................ 15-1

15.2 Governing Code Equation .................................................................................. 15-1

15.3 Test Data ............................................................................................................ 15-2

15.3.1 Testing Used to Derive Code Equation ................................................. 15-2

15.3.2 Rate Effects Testing ............................................................................... 15-6

15.4 Proposed Modifications to Limit State Capacity Equations .............................. 15-9

15.5 Gap Analysis and Mitigation Strategies .......................................................... 15-10

15.5.1 Gap 15A: Rate Effects Testing of Bolt Hole Bearing Phenomenon .... 15-10

15.5.2 Gap 15B: Long-Slotted Hole Tearout Response Under Blast-

Induced Strain Rates ............................................................................ 15-10 ix

CHAPTER 16 BSTR CONNECTING MEMBER LIMIT STATES ................................... 16-1

16.1 Background ........................................................................................................ 16-1

16.2 Governing Code Equation .................................................................................. 16-1

16.3 Test Data ............................................................................................................ 16-2

16.3.1 Testing Used to Derive Code Equation ................................................. 16-2

16.3.2 Rate Effects Testing ............................................................................... 16-5

16.4 Proposed Modifications to Limit State Capacity Equations .............................. 16-5

16.5 Gap Analysis and Mitigation Strategies ............................................................ 16-6

16.5.1 Gap 16A: Validation of an Overstrength Factor for Block Shear

Rupture Limit State Under Blast Loading ............................................. 16-6

CHAPTER 17 WELDED CONNECTIONS OVERVIEW .................................................. 17-1

17.1 Scope .................................................................................................................. 17-1

17.1.1 Weld Type .............................................................................................. 17-1

17.1.2 Welding Process ..................................................................................... 17-1

17.1.3 Base Metal Strength ............................................................................... 17-4

17.2 Welded Connection Characteristics ................................................................... 17-5

17.2.1 Terminology ........................................................................................... 17-5

17.2.2 Limit State Overview ............................................................................. 17-5

17.3 An Overview of the Dynamic Response of Welded Connections ..................... 17-7

17.3.1 State of the Literature Summary ............................................................ 17-7

17.3.2 Weld Material Rate Effects Testing ....................................................... 17-9

CHAPTER 18 FILLET WELD RUPTURE ......................................................................... 18-1

18.1 Background ........................................................................................................ 18-1

18.2 Governing Code Equation .................................................................................. 18-1

18.3 Test Data ............................................................................................................ 18-2

18.3.1 Testing Used to Derive Code Equation ................................................. 18-2

18.3.2 Rate Effects Testing ............................................................................... 18-5

18.3.3 Other Test Data .................................................................................... 18-10

18.4 Proposed Modifications to Limit State Capacity Equations ............................ 18-14

18.5 Gap Analysis and Mitigation Strategies .......................................................... 18-14

18.5.1 Gap 18A: Response of Large Fillet Welds to Blast-Induced Strain

Rates ..................................................................................................... 18-14

18.5.2 Gap 18B: Blast Testing Involving Fillet Welds ................................... 18-15 x

18.5.3 Gap 18C: Fillet Weld Filler Metal Notch Toughness Threshold for

Blast Loading ....................................................................................... 18-15

18.5.4 Gap 18D: State of Stress / Strain at Blast-Induced Fillet Weld

Rupture ................................................................................................. 18-16

CHAPTER 19 GROOVE WELD RUPTURE ...................................................................... 19-1

19.1 Background ........................................................................................................ 19-1

19.2 Governing Code Equation .................................................................................. 19-1

19.3 Test Data ............................................................................................................ 19-2

19.3.1 Testing Used to Derive Code Equation ................................................. 19-2

19.3.2 Rate Effects Testing ............................................................................... 19-2

19.3.3 Other Tests ............................................................................................. 19-9

19.4 Proposed Modifications to Limit State Capacity Equations ............................ 19-11

19.5 Gap Analysis and Mitigation Strategies .......................................................... 19-12

19.5.1 Gap 19A: Response of PJP Welds to Blast-Induced Strain Rates ....... 19-12

19.5.2 Gap 19B: Blast Testing Involving PJP Groove Welds ........................ 19-12

19.5.3 Gap 19C: Groove Weld Filler Metal Notch Toughness Threshold for Blast Loading ................................................................................. 19-12

19.5.4 Gap 19D: State of Stress / Strain at Blast-Induced Groove Weld

Rupture ................................................................................................. 19-13

CHAPTER 20 PLUG / SLOT WELD RUPTURE ............................................................... 20-1

20.1 Background ........................................................................................................ 20-1

20.2 Governing Code Equation .................................................................................. 20-1

20.3 Test Data ............................................................................................................ 20-1

20.3.1 Testing Used to Derive Code Equation ................................................. 20-1

20.3.2 Rate Effects Testing ............................................................................... 20-2

20.4 Proposed Modifications to Limit State Capacity Equations .............................. 20-2

20.5 Gap Analysis and Mitigation Strategies ............................................................ 20-2

20.5.1 Gap 20A: Response of Plug / Slot Welds to Blast-Induced Strain

Rates ....................................................................................................... 20-2

20.5.2 Gap 20B: Blast Testing Involving Plug / Slot Welds ............................ 20-2

20.5.3 Gap 20C: Plug / Slot Weld Filler Metal Notch Toughness

Threshold for Blast Loading .................................................................. 20-3

20.5.4 Gap 20D: State of Stress / Strain at Blast-Induced Plug / Slot Weld

Rupture ................................................................................................... 20-3

CHAPTER 21 BASE METAL FAILURE ............................................................................ 21-1 xi

21.1 Background ........................................................................................................ 21-1

21.2 Governing Code Equation .................................................................................. 21-1

21.3 Test Data ............................................................................................................ 21-1

21.3.1 Testing Used to Derive Code Equation ................................................. 21-1

21.3.2 Rate Effects Testing ............................................................................... 21-1

21.4 Proposed Modifications to Limit State Capacity Equations .............................. 21-5

21.5 Gap Analysis and Mitigation Strategies ............................................................ 21-5

21.5.1 Gap 21A: Validation of an Overstrength Factor for Weld Metal

Rupture Under Blast Loading ................................................................ 21-5

CHAPTER 22 GAP ANALYSIS SUMMARY .................................................................... 22-1

22.1 Design Guidance Recommendations ................................................................. 22-1

22.1.1 Material Property Increase Factors ........................................................ 22-1

22.1.2 Proposed Modifications to Limit State Capacity Equations .................. 22-2

22.2 Limit State Gaps and Mitigation Strategies ....................................................... 22-8

22.2.1 Ranking of Gaps by SMEs ..................................................................... 22-8

APPENDIX A REFERENCES .............................................................................................. A-1

APPENDIX B DEFINITIONS ...............................................................................................B-1

APPENDIX C LIMIT STATE CAPACITY CALCULATIONS ...........................................C-1

APPENDIX D EXPORT-CONTROLLED REFERENCES ................................................. D-1 xii

LIST OF FIGURES

Figure 1-1. Illustration of Typical Moment Rotation Curve for Simple Shear Connections. .. 1-11

Figure 1-2. Finite Element Calculation Results Illustrating the Progression of Member Blast

Response; Early Time (Left) Moving to Late Time (Right). ............................................... 1-12

Figure 1-3. Normalized SDOF Dynamic Reaction Histories for Different Levels of Peak Reflected

Pressure. ............................................................................................................................... 1-13

Figure 1-4. Normalized MDOF Dynamic Reaction Histories for Different Levels of Peak

Reflected Pressure. ............................................................................................................... 1-14

Figure 1-5. Normalized MDOF Dynamic Reaction Histories for Different Levels of Peak

Reflected Pressure and Variations of the Baseline System. ................................................ 1-15

Figure 1-6. An Adaptation of the Seismic Performance Factor Methodology Included in FEMA

P695 to Blast Loaded Connection Limit States. .................................................................. 1-18

Figure 2-1. Methods of Concrete Anchorage. ............................................................................ 2-2

Figure 2-2. Anchorage Resistance Mechanisms. ........................................................................ 2-3

Figure 2-3. Types of Anchors and Their Resistance Mechanisms. ............................................ 2-4

Figure 2-4. Effect of Temperature on Compressive Strength of Concrete. ................................ 2-7

Figure 2-5. Concrete Compression Rate Effects Test Data Compared with the CEB Model. ... 2-9

Figure 2-6. Design Curve for DIF for Ultimate Compressive Strength of Concrete. ................. 2-9

Figure 2-7. Concrete Tension Rate Effects Test Data Compared with the Various Versions of the

CEB Model. ......................................................................................................................... 2-10

Figure 2-8. Design Curve for DIF for Ultimate Tensile Strength of Concrete. ........................ 2-11

Figure 2-9. DIFs for Reinforcing Steel Proposed by Malvar (1998). ....................................... 2-14

Figure 3-1. Breakout Cone in Tension. ....................................................................................... 3-1

Figure 3-2. Concrete Breakout Loads in Tension Unaffected by Spacing or Edge Effects. ...... 3-3

Figure 3-3. Diagrams and Dimensions of Post-Installed Anchors Tested in Rodriguez et al. (2001).

................................................................................................................................................ 3-4

Figure 3-4. Cracked Concrete Specimens in Rodriguez et al. (2001). ....................................... 3-5

Figure 3-5. Generalized Dynamic Loading History from Rodriguez et al. (2001). .................... 3-5

Figure 3-6. Test Setup Used in Salim et al. (2005). .................................................................... 3-7

Figure 3-7. Anchors Tested in Salim et al. (2005). ..................................................................... 3-7

Figure 3-8. Anchors Tested in Solomos and Berra (2006). ........................................................ 3-8

Figure 3-9. Load-Displacement Results for the 0.47” (12 mm) Diameter Specimens from Solomos and Berra (2006). ................................................................................................................... 3-9

Figure 3-10. Schematic Illustrations of Anchors Tested in Hoehler et al. (2011). ................... 3-10

Figure 3-11. Summary of Loading Rate Impact on Concrete Breakout Strength in Tension for

Testing Efforts up to 2011. .................................................................................................. 3-11

Figure 3-12. Pictures of Anchors Tested in Abdul-Hamid (2019). .......................................... 3-11

Figure 3-13. Generalized Impact Load History from Collins et al. (1989). ............................. 3-15

Figure 3-14. Test Setup Described in Hunziker et al. (1999). .................................................. 3-15

Figure 3-15. Photographs from Tension Testing of Adhesive Anchor in Masonry Substrates from

Braimah et al. (2014). .......................................................................................................... 3-17

Figure 4-1. Idealized Load-Displacement Curves for Tension-Loaded Anchors Exhibiting Various

Failure Modes; Pullout Failure Modes are Represented by Curves a1,1, a1,2, a1,3, and a1,4. ... 4-1

Figure 4-2. Failure Mechanism of an Expansion Anchor. .......................................................... 4-2 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379961 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379963 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379963 xiii

Figure 4-3. Maximum Average Bearing Pressure Under Anchor Head to Assure Concrete

Breakout from Furche (1994). ............................................................................................... 4-3

Figure 4-4. Predicted Pullout Load vs. Actual Pullout Load for L-Bolts. .................................. 4-3

Figure 4-5. Influence of Loading Rate on Pull-through Failure. ................................................ 4-4

Figure 5-1. Local Side-Face Blowout Failure of a Headed Stud Loaded in Tension with Small

Edge Distance. ....................................................................................................................... 5-1

Figure 5-2. Schematic of Side-Face Blowout Failure of a Headed Stud Near an Edge. ............ 5-1

Figure 5-3. Failure Load of Tension-Loaded Headed Studs Having a Constant Edge Distance as a Function of Embedment Depth. .......................................................................................... 5-2

Figure 5-4. Comparison of Best-Fit Equation with Side-Face Blowout Test Data. ................... 5-3

Figure 5-5. Typical Side-Face Blowout Load Versus Displacement Relationship. ................... 5-3

Figure 6-1. Classification of Bonded Anchors from Comité Euro-International du Béton (CEB)

(1994). .................................................................................................................................... 6-1

Figure 6-2. Failure Modes of Bonded Anchors Under Tensile Load. ........................................ 6-2

Figure 6-3. Generalized Load-Displacement Curves for Adhesive Anchors from Meszaros (1999).

................................................................................................................................................ 6-2

Figure 6-4. Failure Modes of Bonded Anchors Under Tensile Load. ........................................ 6-3

Figure 6-5. Test Setups Employed in Fujikake et al. (2003). ..................................................... 6-4

Figure 6-6. Idealized Combined Breakout / Bond Failure from Fujikake et al. (2003). ............ 6-5

Figure 6-7. Relationship Between Dynamic Bond Resistance and Loading Rate Compared with the Data Obtained by Fujikake et al. (2003). ......................................................................... 6-5

Figure 6-8. Influence of Loading Rate on Adhesive Bond Failure. ............................................ 6-6

Figure 7-1. Idealized Load-Displacement Curves for Anchors Subjected to Tension and Shear.

................................................................................................................................................ 7-1

Figure 7-2. Concrete Breakout Loads in Shear Unaffected by Spacing or Edge Effects. .......... 7-3

Figure 7-3. Illustration of Shear Test Setup Used in Hallowell (1996). ..................................... 7-4

Figure 7-4. Reinforcing Steel Layouts Used in Hallowell (1996). ............................................. 7-5

Figure 7-5. Impact of Hairpin Anchor Reinforcement on the Strength and Ductility of a Single

Cast-in Anchor Loaded Dynamically in Shear Near an Edge. .............................................. 7-5

Figure 7-6. Impact of Hairpin Anchor Reinforcement on the Strength and Ductility of Two Cast-in Anchors Loaded Dynamically in Shear Near an Edge. ..................................................... 7-6

Figure 8-1. Free-Body Diagram Illustrating Pryout Phenomenon. ............................................. 8-1

Figure 8-2. Ratio of Applied Shear Force (Vu(test)) and the Nominal Tensile Capacity of Various

Types of Anchors. .................................................................................................................. 8-2

Figure 8-3. Test-to-Predicted Capacity Versus Embedment Depth Ratio for Database Compiled in Anderson and Meinheit (2005). ......................................................................................... 8-2

Figure 9-1. Interaction of Tension and Shear for Anchor Rods, Headed Studs, and Post-Installed

Anchors (Both Concrete and Steel Failure Modes). .............................................................. 9-2

Figure 10-1. Examples of BSTR Connection Failures During Blast Testing. .......................... 10-1

Figure 10-2. Example of Strength Increase in Mild Steel Due to Increasing Strain Rate. ....... 10-6

Figure 10-3. Design DIF Curves for Structural Steels Included in Various Blast Design Standards.

.............................................................................................................................................. 10-6

Figure 10-4. Design DIF Curves for 50 ksi (345 MPa) Structural Steels Based on Murray et al.

(2018). .................................................................................................................................. 10-7

Figure 11-1. Load Versus Elongation Relationship and Frequency Distribution for High Strength

Bolts Tested in Torqued Tension and Direct Tension. ........................................................ 11-4 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379975 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379975 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379981 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127379981 xiv

Figure 11-2. Reserve Tensile Strength of Torqued ASTM A325 Bolts. .................................. 11-4

Figure 11-3. Schematic Diagrams Showing Testing Methods Used in Mouritz (1994). ......... 11-5

Figure 11-4. Failure Modes Observed in Metric Grade 8.8 Bolts Pulled in Tension in Munoz-

Garcia et al. (2005). ............................................................................................................. 11-5

Figure 11-5. Specimens and Results for SHPB Tests on Threaded Rods in Tension, Shear, and

Combined Tension-Shear Stress Paths. ............................................................................... 11-6

Figure 11-6. Effect of Thread Length on Force Versus Displacement Response. ................... 11-8

Figure 12-1. Shear Strength vs. Tensile Strength for ASTM A325 and A490 Bolts. .............. 12-2

Figure 12-2. Bolt Shear Testing Data Plotted Against Proposed Reduction Factors Considering the Effect of Connection Length. ......................................................................................... 12-3

Figure 12-3. Test Specimen and Bolt Failure Modes Observed in Horsfall et al. (2011). ....... 12-4

Figure 12-4. Specimen Configurations and Results from Rabalais (2015). ............................. 12-5

Figure 12-5. Single-Shear Configuration Tested in Hadjioannou et al. (2017). ....................... 12-6

Figure 12-6. Single-Shear Configuration Tested in Sanborn and Stewart (2020). ................... 12-6

Figure 12-7. Single-Shear Test Setup Employed in Vigness et al. (1962). .............................. 12-8

Figure 12-8. Test Setup and Bolt Shear Failures Observed in Wolfson (2008). ...................... 12-8

Figure 13-1. Standoff Base Plate Installation Conditions. ........................................................ 13-2

Figure 13-2. Ratio of Measured Ultimate and Calculated Characteristic (5% Fractile) as a Function of Bolt Diameter from Scheer et al. (1987) as Documented in Eligehausen et al. (2006). . 13-2

Figure 13-3. Ratio of Measured Ultimate and Calculated Characteristic (5% Fractile) as a Function of Superimposed Tensile Force from Scheer et al. (1987) as Documented in Eligehausen et al.

(2006). .................................................................................................................................. 13-3

Figure 14-1. Interaction of Tension and Shear for High-Strength Bolts. ................................. 14-2

Figure 14-2. Interaction of Tension and Shear for Anchor Rods, Headed Studs, and Post-Installed

Anchors. ............................................................................................................................... 14-3

Figure 15-1. Illustration of Bolt Hole Bearing Failure Modes from Frank and Yura (1981). .. 15-1

Figure 15-2. Test Setup for Kim and Yura (1996).................................................................... 15-2

Figure 15-3. Specimen Geometry for Kim and Yura (1996). ................................................... 15-3

Figure 15-4. Test Setup and Specimen Geometry for Lewis and Zwerneman (1996). ............ 15-3

Figure 15-5. Ultimate Test Loads vs. ANSI/AISC 360 Bolt Hole Bearing and Tearout Strength

Capacity from Kim and Yura (1996) and Lewis and Zwerneman (1996). .......................... 15-4

Figure 15-6. Test Setup for Frank and Yura (1981). ................................................................ 15-5

Figure 15-7. Typical Load vs. Deformation Curve from Frank and Yura (1981). ................... 15-6

Figure 15-8. Test Specimens from Birch and Alves (2000). .................................................... 15-7

Figure 15-9. Load vs. Displacement Results from Birch and Alves (2000). ............................ 15-7

Figure 16-1. Idealized Block Shear Failure Surface. ................................................................ 16-1

Figure 16-2. Ubs Factor for Different Block Shear Stress Distributions. .................................. 16-2

Figure 16-3. Coped Beam Specimen and Results from Birkemoe and Gilmor (1978). ........... 16-3

Figure 17-1. Common Welding Processes Used in Building Construction. ............................. 17-2

Figure 17-2. Schematic Showing Relationship Between Notch Toughness and Levels of Structural

Performance for Various Loading Rates. ............................................................................. 17-4

Figure 17-3. Welding Terminology. ......................................................................................... 17-5

Figure 17-4. Cross Section View Through a Weld. .................................................................. 17-5

Figure 17-5. Typical Pre-Northridge Beam-Column Moment Connection. ............................. 17-8

Figure 17-6. Illustration of Spot Weld Generation Process. ..................................................... 17-9

Figure 17-7. Weld Metal Specimen and Results from Wang and Lu (2005). ........................ 17-10 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127380001 file:///C:/Users/weaver/Desktop/TR-20-36_Blast%20Loaded%20Connections%20Design%20Guidance_2023_xx_xx.docx%23_Toc127380015 xv

Figure 17-8. Weld Metal Specimens from Grimsmo et al. (2017). ........................................ 17-10

Figure 17-9. Tension Testing Results on Weld Material at Different Strain Rates from Grimsmo et al. (2017). ....................................................................................................................... 17-11

Figure 17-10. Specimens Tested in He et al. (2017).