NEHRP Recommended Seismic Provisions for New and Other Structures

CoverThe National Earthquake Hazards Reduction Program (NEHRP) Recommended Seismic Provisions for New Buildings and Other Structures is a well-known technical resource document for improving national seismic design standards and model building codes. Each edition of the NEHRP Provisions has been developed based on the most recent advancements in earthquake engineering and research.

The 2020 NEHRP Provisions continues to apply the current state-of-knowledge in earthquake engineering for improving the seismic design of buildings and other structures. It presents a set of recommended improvements to the ASCE/SEI 7-16 Standard: Minimum Design Loads and Associated Criteria for Buildings and Other Structures, and nine resource papers on new concepts, suggested future development, and technical information in support of the recommended improvements.

The NEHRP Provisions is developed and evaluated through an expert-based consensus process to ensure validity and quality of the recommended new changes. It is intended primarily for use by national standards and code organizations and earthquake engineering professionals.

The NEHRP Recommended Seismic Provisions for New and Other Structures  is available:

for free download online or for sale on Amazon for $21.99

Guide to Using the 2020 NEHRP Provisions

Part 1 of the Provisions provides recommended changes to the seismic requirements of ASCE 7-16, Chapters 11 to 22. For a given chapter, only those sections with recommended modifications or additions are shown. Therefore, the Provisions Part 1 should be used side-by-side with ASCE 7-16 in order to grasp the full context of each chapter.

Part 2 of the Provisions provides a complete commentary for each chapter. It is comprised of the new commentary to each proposed change contained in Part 1 along with the existing ASCE 7-16 commentary to unchanged sections. Therefore, the Part 2 Commentary is self-contained. Black bars  in the columns indicate new commentary matching Provisions Part 1 changes.

Part 3 provides resource papers adopted in the 2020 Provisions cycle. These resource papers are self- contained and not necessarily directly associated with a Part 1 provision. They are not written in standards language format.

The table in the Introduction provides a summary of Part 1 topics along with reference sections in Parts 1 and 2, and any relevant resource paper in Part 3.


CONTENTS

INTENT.............................................................................................................................................. 1

PART 1, PROVISIONS..................................................................................................................... 11

CHAPTER 11, SEISMIC DESIGN CRITERIA..................................................................................... 12

CHAPTER 12, SEISMIC DESIGN REQUIREMENTS FOR BUILDING STRUCTURES.......................... 24

CHAPTER 13, SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONENTS........... 40

CHAPTER 14, MATERIAL SPECIFIC SEISMIC DESIGN AND DETAILING REQUIREMENTS............. 54

CHAPTER 15, SEISMIC DESIGN REQUIREMENTS FOR NONBUILDING STRUCTURES................... 74

CHAPTER 18, SEISMIC DESIGN REQUIREMENTS FOR STRUCTURES WITH DAMPING SYSTEMS... 77

CHAPTER 19, SOIL-STRUCTURE INTERACTION FOR SEISMIC DESIGN........................................ 79

CHAPTER 20, SITE CLASSIFICATION PROCEDURE FOR SEISMIC DESIGN.................................. 86

CHAPTER 21, SITE SPECIFIC GROUND MOTION PROCEDURES FOR SEISMIC DESIGN............... 90

CHAPTER 22, SEISMIC GROUND MOTION AND LONG-PERIOD TRANSITION MAPS..................... 96

mapPART 2, COMMENTARY................................................................................................................ 113

COMMENTARY TO CHAPTER 11, SEISMIC DESIGN CRITERIA..................................................... 114

COMMENTARY TO CHAPTER 12, SEISMIC DESIGN REQUIREMENTS FOR BUILDING STRUCTURES          140

COMMENTARY TO CHAPTER 13, SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONENTS...248

COMMENTARY TO CHAPTER 14, MATERIAL-SPECIFIC SEISMIC DESIGN AND DETAILING REQUIREMENTS.... 306

COMMENTARY TO CHAPTER 15, SEISMIC DESIGN REQUIREMENTS FOR NONBUILDING STRUCTURES  360

COMMENTARY TO CHAPTER 16, SEISMIC RESPONSE HISTORY PROCEDURES....................... 407

COMMENTARY TO CHAPTER 17, SEISMIC DESIGN REQUIREMENTS FOR SEISMICALLY ISOLATED STRUCTURES..... 436

COMMENTARY TO CHAPTER 18, SEISMIC DESIGN REQUIREMENTS FOR STRUCTURES WITH DAMPING SYSTEMS..... 478

COMMENTARY TO CHAPTER 19, SOIL-STRUCTURE INTERACTION FOR SEISMIC DESIGN....... 495

COMMENTARY TO CHAPTER 20, SITE CLASSIFICATION PROCEDURE FOR SEISMIC DESIGN . 506

COMMENTARY TO CHAPTER 21, SITE-SPECIFIC GROUND MOTION PROCEDURES FOR SEISMIC DESIGN.... 514

COMMENTARY TO CHAPTER 22, SEISMIC GROUND MOTION AND LONG-PERIOD TRANSITION MAPS     524

APPENDIX PROJECT PARTICIPANTS........................................................................................... 546


Wall Connections


CONTENTS

FOREWORD..................................................................................................................................... VI

PREFACE AND ACKNOWLEDGEMENTS........................................................................................ VIII

INTRODUCTION............................................................................................................................ XXX

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INTENT.............................................................................................................................................. 1

1.1                INTENT............................................................................................................................................................. 1

1.1.1                 Structure Collapse........................................................................................................................ 1

1.1.2                 Nonstructural Damage................................................................................................................ 3

1.1.3                 Hazardous Materials................................................................................................................... 3

1.1.4                 Preservation of Egress................................................................................................................. 3

1.1.5                 Functionality of Critical or Essential Facilities....................................................................... 3

1.1.6                 Repair Costs.................................................................................................................................. 4

2.1                COMMENTARY TO THE INTENT........................................................................................................... 4

2.1.1                 Structure Collapse........................................................................................................................ 5

2.1.2                 Nonstructural Damage................................................................................................................ 6

2.1.3                 Hazardous Materials................................................................................................................... 7

2.1.4                 Preservation of Egress................................................................................................................. 7

2.1.5                 Functionality of Critical or Essential Facilities....................................................................... 7

2.1.6                 Repair Costs.................................................................................................................................. 8

REFERENCES................................................................................................................................................................. 9

REFERENCE DOCUMENT................................................................................................................ 10

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PART 1, PROVISIONS..................................................................................................................... 11

CHAPTER 11, SEISMIC DESIGN CRITERIA..................................................................................... 12

SECTION 11.2 DEFINITIONS................................................................................................................................... 12

SECTION 11.3 SYMBOLS......................................................................................................................................... 13

SECTION 11.4 SEISMIC GROUND MOTION VALUES................................................................................... 15

11.4.1              Near-fault sites............................................................................................................................ 15

11.4.2               Site Class.................................................................................................................................... 15

11.4.2.1               Default Site Class............................................................................................... 15

11.4.3                              Risk-Targeted Maximum Considered Earthquake (MCER) Spectral Response Acceleration Parameters.... 15

11.4.4               Design Spectral Acceleration Parameters............................................................................ 15

11.4.5              Design Response Spectrum...................................................................................................... 16

11.4.5.1               Multi-Period Design Response Spectrum..................................................... 16

11.4.5.2               Two-Period Design Response Spectrum....................................................... 16

11.4.6              Risk-Targeted Maximum Considered Earthquake (MCER) Response Spectrum........... 17

11.4.7              Site-Specific Ground Motion Procedures.............................................................................. 18

SECTION 11.5 IMPORTANCE FACTOR AND RISK CATEGORY................................................................ 18

11.5.1              Importance Factor..................................................................................................................... 18

11.5.2              Protected Access for Risk Category IV.................................................................................. 18

SECTION 11.6  SEISMIC DESIGN CATEGORY................................................................................................. 18

SECTION 11.7 DESIGN REQUIREMENTS FOR SEISMIC DESIGN CATEGORY A............................... 20


SECTION 11.8 GEOLOGIC HAZARDS AND GEOTECHNICAL INVESTIGATION................................ 20

11.8.1              Site Limitation for Seismic Design Categories E and F...................................................... 20

11.8.2                              Geotechnical Investigation Report Requirements for Seismic Design Categories C through F     20

11.8.3                              Additional Geotechnical Investigation Report Requirements for Seismic Design Categories D through F........ 20

SECTION 11.9 VERTICAL GROUND MOTIONS FOR SEISMIC DESIGN................................................. 21

11.9.1              General......................................................................................................................................... 21

11.9.2              MCER Vertical Response Spectrum....................................................................................... 21

11.9.3              Design Vertical Response Spectrum...................................................................................... 22

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CHAPTER 12, SEISMIC DESIGN REQUIREMENTS FOR BUILDING STRUCTURES......... 24

SECTION 12.2.1 SEISMIC FORCE-RESISTING SYSTEM SELECTION AND LIMITATIONS............. 24

12.2.1.1         Alternative Seismic Force-Resisting Systems...................................................................... 25

12.2.1.2         Elements of Seismic Force-Resisting Systems..................................................................... 25

SECTION 12.2.3.2 TWO-STAGE ANALYSIS PROCEDURE........................................................................... 26

12.2.3.2.1    Vertical Combinations of Systems......................................................................................... 26

12.2.3.2.2    One-Story Structures with Flexible Diaphragms and Rigid Vertical Elements.............. 26

SECTION 12.2.5 SYSTEM-SPECIFIC REQUIREMENTS................................................................................. 27

12.2.5.4     Increased Structural Height Limit for Steel Eccentrically Braced Frames, Steel Special Concentrically Braced Frames, Steel Buckling-Restrained Braced Frames, Steel Special Plate Shear Walls, Steel and Concrete Coupled Composite Plate Shear Walls, Reinforced Concrete Ductile Coupled Walls, and Special Reinforced

Concrete Shear Walls................................................................................................................ 27

SECTION 12.3.2 IRREGULAR AND REGULAR CLASSIFICATION............................................................ 27

12.3.2.2      Vertical Irregularity.................................................................................................................. 27

SECTION 12.3.3 LIMITATIONS AND ADDITIONAL REQUIREMENTS FOR SYSTEMS

WITH STRUCTURAL IRREGULARITIES............................................................................................ 30

12.3.3.1         Prohibited Vertical Irregularities for Seismic Design Categories D through F............... 30

12.3.3.2         Extreme Weak Stories............................................................................................................... 30

12.3.3.3         Elements Supporting Discontinuous Walls or Frames........................................................ 30

12.3.3.4         Increase in Forces Caused by Irregularities for Seismic Design Categories D

through F..................................................................................................................................... 30

SECTION 12.3.4 REDUNDANCY............................................................................................................................. 30

12.3.4.1         Conditions Where Value of ρ is 1.0........................................................................................ 31

12.3.4.2         Redundancy Factor, ρ, for Seismic Design Categories D through F................................ 31

SECTION 12.5.3 SEISMIC DESIGN CATEFORY C........................................................................................... 31

12.5.3.1     Structures with Horizontal Structural Irregularities.............................................................. 31

SECTION 12.6 ANALYSIS PRODECURE SELECTION................................................................................... 32

SECTION 12.7.3 STRUCTURAL MODELING..................................................................................................... 32

SECTION 12.8.6 DISPLACEMENT AND DRIFT DETERMINATION........................................................... 32

12.8.6.1         Minimum Base Shear for Computing Displacement and Drift.......................................... 32

12.8.6.2         Period for Computing Displacement and Drift..................................................................... 32

12.8.6.3         Design Earthquake and Maximum Considered Earthquake Displacement..................... 32

12.8.6.4         Design Story Drift Determination........................................................................................... 33

SECTION 12.9.1.4.2 SCALING OF DISPLACEMENTS AND DRIFTS......................................................... 33

SECTION 12.10 DIAPHRAGMS, CHORDS AND COLLECTORS.................................................................. 33

12.10.4       Alternative Diaphragm Design Provisions for One-Story Structures with Flexible Diaphragms and Rigid Vertical Elements........ 34


12.10.4.1            Limitations.......................................................................................................... 34

12.10.4.2            Design................................................................................................................... 35

12.10.4.2.1          Seismic Design Forces.................................................................. 35

12.10.4.2.2          Diaphragm Shears......................................................................... 36

12.10.4.2.3          Diaphragm Chords........................................................................ 36

12.10.4.2.4          Collector Elements and Their Connections................................... 36

12.10.4.2.5          Diaphragm Deflection................................................................... 36

SECTION 12.12 DRIFT AND DEFORMATION................................................................................................... 37

12.12.1          Story Drift Limit......................................................................................................................... 37

12.12.2          Structural Separation................................................................................................................ 37

12.12.3          Members Spanning between Structures................................................................................. 38

12.12.4          Deformation Compatibility for Seismic Design Categories D through F........................ 38

SECTION 12.14 SIMPLIFIED ALTERNATIVE STRUCTURAL DESIGN CRITERIA FOR

SIMPLE BEARING WALL OR BUILDING FRAME SYSTEMS..................................................... 38

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CHAPTER 13, SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONENTS........... 40

SECTION 13.1 SCOPE................................................................................................................................................ 40

13.1.1              Scope............................................................................................................................................ 40

13.1.2              Seismic Design Category......................................................................................................... 40

13.1.3              Component Importance Factor............................................................................................... 40

13.1.6         Application of Nonstructural Component Requirements to Nonbuilding Structures..... 40

SECTION 13.2.2 SPECIAL CERTIFICATION REQUIREMENTS FOR DESIGNATED SEISMIC SYSTEMS       41

SECTION 13.2.8 SUPPORTED NONSTRUCTURAL COMPONENTS WITH GREATER THAN

OR EQUAL TO 20% COMBINED WEIGHT......................................................................................... 41

SECTION 13.3.1 SEISMIC DESIGN FORCES...................................................................................................... 41

13.3.1.1         Amplification with Height, Hf................................................................................................. 42

13.3.1.2         Structure Ductility Reduction Factor, Rµ............................................................................... 43

13.3.1.3         Component Resonance Ductility Factor, CAR....................................................................... 44

13.3.1.4         Component Strength, Rpo.......................................................................................................... 44

13.3.1.5         Nonlinear Response History Analysis.................................................................................... 44

13.3.1.6         Vertical Force............................................................................................................................. 44

13.3.1.7         Nonseismic Loads..................................................................................................................... 45

SECTION 13.3.2 SEISMIC RELATIVE DISPLACEMENTS............................................................................. 45

13.3.2.1         Displacements within Structures............................................................................................. 45

13.3.2.2         Displacements between Structures.......................................................................................... 45

SECTION 13.4 NONSTRUCTURAL COMPONENT ANCHORAGE AND ATTACHMENT................... 46

13.4.1              Design Force in the Attachment............................................................................................. 46

13.4.2              Anchors in Concrete or Masonry............................................................................................ 46

13.4.2.1               Anchors in Concrete.......................................................................................... 46

13.4.2.2               Anchors in Masonry.......................................................................................... 46

SECTION 13.5.3 EXTERIOR NONSTRUCTURAL WALL ELEMENTS AND CONNECTIONS............ 46

SECTION 13.5.10 EGRESS STAIRS AND RAMPS............................................................................................. 47

SECTION 13.5.11 PENTHOUSES AND ROOFTOP STRUCTURES............................................................... 47

13.5.11.1   Seismic Force-Resisting Systems for Penthouses and Rooftop Structures..................... 47

SECTION 13.6.2.1 HVACR EQUIPMENT............................................................................................................. 49

13.6.2.1      HVACR Equipment................................................................................................................. 49

SECTION 13.6.4 COMPONENT SUPPORTS......................................................................................................... 49

13.6.4.1     Design Basis............................................................................................................................... 49


13.6.4.6         Equipment Platforms and Support Structures....................................................................... 49

13.6.4.7         Distribution System Supports.................................................................................................. 50

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CHAPTER 14, MATERIAL SPECIFIC SEISMIC DESIGN AND DETAILING REQUIREMENTS............. 54

SECTION 14.1.5 COLD-FIRMED STEEL DECK DIAPHRAGMS.................................................................. 54

14.1.5.1          Modifications to AISI S400.................................................................................................... 54

14.1.5.1.1          AISI S400, Section A2.1................................................................................... 54

14.1.5.1.2          AISI S400, Section A5...................................................................................... 55

14.1.5.1.3          AISI S400, Section F1.2................................................................................... 55

14.1.5.1.4      AISI S400, Section F1.4.1.2............................................................................. 55

14.1.5.1.5      AISI S400, Section F3:..................................................................................... 55

SECTION 14.3.3 SEISMIC REQUIREMENTS FOR COMPOSITE STEEL AND CONCRETE STRUCTURES      58

SECTION 14.3.5 SEISMIC REQUIREMENTS FOR COUPLED COMPOSITE PLATE SHEAR

WALLS – CONCRETE FILLED (CC-PSW/CF).................................................................................... 59

14.3.5.1         General......................................................................................................................................... 59

14.3.5.1.1          Scope.................................................................................................................... 59

14.3.5.1.2          Notation............................................................................................................... 59

14.3.5.1.3          Glossary............................................................................................................... 59

14.3.5.2         Basics of Design......................................................................................................................... 60

14.3.5.3         Analysis....................................................................................................................................... 60

14.3.5.3.1          Stiffness............................................................................................................... 60

14.3.5.3.2          Required Strength for Coupling Beams........................................................ 60

14.3.5.3.3          Required Strength for Composite Walls........................................................ 61

14.3.5.3.4          Capacity-Limited Seismic Load..................................................................... 61

14.3.5.4         Composite Wall Requirements................................................................................................ 61

14.3.5.4.1          Minimum Area of Steel..................................................................................... 61

14.3.5.4.2          Steel Plate Slenderness Requirement for Composite Walls........................ 61

14.3.5.4.4      Tie-to-Plate Connection................................................................................... 62

14.3.5.5         Composite Coupling Beam Requirements............................................................................ 62

14.3.5.5.1          Minimum Area of Steel..................................................................................... 62

14.3.5.5.2          Slenderness Requirement for Coupling Beams............................................ 62

14.3.5.5.3          Flexure-Critical Coupling Beams................................................................... 62

14.3.5.6         Composite Wall Strength.......................................................................................................... 63

14.3.5.6.1          Tensile Strength................................................................................................. 63

14.3.5.6.2          Comprehensive Strength................................................................................... 63

14.3.5.6.3          Flexural Strength................................................................................................ 63

14.3.5.6.4          Combined Axial Force and Flexure................................................................ 63

14.3.5.6.5          Shear Strength.................................................................................................... 63

14.3.5.7         Composite Coupling Beam Strength...................................................................................... 64

14.3.5.7.1          Flexible Strength................................................................................................ 64

14.3.5.7.2          Shear Strength.................................................................................................... 64

14.3.5.8         Coupling Beam-to-Wall Connections.................................................................................... 64

14.3.5.8.1          Required Flexular Strength.............................................................................. 64

14.3.5.8.2          Required Shear Strength................................................................................... 64

14.3.5.8.3          Rotation Capacity............................................................................................. 65

14.3.5.9         Composite Wall-to-Foundation Connections....................................................................... 65

14.3.5.9.1          Required Strengths............................................................................................. 65

14.3.5.10     Protected Zones.......................................................................................................................... 65

14.3.5.11     Demand Critical Welds in Connections................................................................................ 65

SECTION 14.5.2 SEISMIC REQUIREMENTS FOR CROSS LAMINATED TIMBER SHEAR

WALLS............................................................................................................................................................ 66

14.5.2.1         Scope............................................................................................................................................ 66

14.5.2.1.1           Notation.............................................................................................................. 66


14.5.2.1.2          Terminology........................................................................................................ 66

14.5.2.2          Application Requirements....................................................................................................... 67

14.5.2.3          CLT Shear Wall Requirements.............................................................................................. 68

14.5.2.3.1          CLT panels.......................................................................................................... 68

14.5.2.3.2          Top- and bottom-of-wall angle connector.................................................... 68

14.5.2.3.3           Adjoining panel edge connector.................................................................... 69

14.5.2.3.4           Hold-down system............................................................................................ 70

14.5.2.3.5          Compression zone............................................................................................. 70

14.5.2.3.6          Other load path connections to CLT wall panels......................................... 70

14.5.2.3.7          CLT shear walls with shear resistance provided by high aspect ratio panels only   71

14.5.2.4         Deflection.................................................................................................................................... 71

14.5.2.5         Nominal unit shear capacity.................................................................................................... 71

14.5.2.6          ASD and LRFD design unit shear capacities....................................................................... 72

14.5.2.7          Diaphragm Requirements........................................................................................................ 72

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CHAPTER 15, SEISMIC DESIGN REQUIREMENTS FOR NONBUILDING STRUCTURES................... 74

SECTION 15.2 NONBUILDING STRUCTURES CONNECTED BY NONSTRUCTURAL COMPONENTS TO OTHER ADJACENT STRUCTURES....... 74

15.2.1                              Nonbuilding Structures Connected by Nonstructural Components to Other Adjacent Structures 74

15.2.2              Architectural, Mechanical, and Electrical Components Spanning Between

Nonbuilding Structures............................................................................................................. 74

SECTION 15.3 NONBUILDING STRUCTURES SUPPORTED BY OTHER STRUCTURES.................. 74

15.3.1              Less Than 20% Combined Weight Condition...................................................................... 74

15.3.2                              Supported Nonbuilding Structures with Greater Than or Equal to 20% Combined Weight           75

15.3.3                              Architectural, Mechanical, and Electrical Components Supported by Nonbuilding Structures     75

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CHAPTER 18, SEISMIC DESIGN REQUIREMENTS FOR STRUCTURES WITH DAMPING SYSTEMS.......... 77

SECTION 18.2.3.2 EQUIVALENT LATERAL FORCE PROCEDURE........................................................... 77

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CHAPTER 19, SOIL-STRUCTURE INTERACTION FOR SEISMIC DESIGN........................................ 79

SECTION 19.3 FOUNDATION EFFECTS.............................................................................................................. 79

19.3.1              Foundation Damping Requirements....................................................................................... 79

19.3.2              Effective Damping Ratio.......................................................................................................... 79

19.3.3              Radiation Damping for Rectangular Foundations............................................................... 81

19.3.4              Radiation Damping for Circular Foundations...................................................................... 83

19.3.5              Soil Damping.............................................................................................................................. 84

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CHAPTER 20, SITE CLASSIFICATION PROCEDURE FOR SEISMIC DESIGN.................................. 86

SECTION 20.1 SITE CLASSIFICATION................................................................................................................ 86

SECTION 20.2 SITE CLASS DEFINITIONS......................................................................................................... 86

20.2.1              Site Class F.................................................................................................................................. 87

20.2.2              Site Class E (Soft Clay)............................................................................................................ 87

20.2.3              Site Classes C, CD, D, DE and E............................................................................................ 87

20.2.4              Site Class B and BC (Medium Hard and Soft Rock)........................................................... 87

20.2.5              Site Class A (Hard Rock)......................................................................................................... 87

SECTION 20.3 ESTIMATION OF SHEAR WAVE VELOCITY PROFILES................................................. 88

SECTION 20.4 DEFINITIONS OF SITE CLASS PARAMETERS.................................................................... 88


20.4.1 vs , AVERAGE SHEAR WAVE VELOCITY............................................................................................. 88

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CHAPTER 21, SITE SPECIFIC GROUND MOTION PROCEDURES FOR SEISMIC DESIGN............... 90

SECTION 21.1 SITE RESPONSE ANALYSIS....................................................................................................... 90

21.1.1              Base Ground Motions............................................................................................................... 90

21.1.2              Site Condition Modeling........................................................................................................... 90

21.1.3              Site Response Analysis and Computed Results................................................................... 90

SECTION 21.2 RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER)

GROUND MOTION HAZARD ANALYSIS........................................................................................... 91

21.2.1              Probabilistic (MCER) Ground Motions.................................................................................. 91

21.2.2              Deterministic (MCER) Ground Motions................................................................................ 91

21.2.3              Site-Specific MCER Response Spectrum............................................................................... 93

SECTION 21.3 DESIGN RESPONSE SPECTRUM.............................................................................................. 93

SECTION 21.4 DESIGN ACCELERATION PARAMETERS............................................................................ 93

SECTION 21.5 MAXIMUM CONSIDERED EARTHQUAKE GEOMETRIC MEAN (MCEG)

PEAK GROUND ACCELERATION........................................................................................................ 94

21.5.1              Probabilistic MCEG Peak Ground Acceleration................................................................... 94

21.5.2              Deterministic MCEG Peak Ground Acceleration.................................................................. 94

21.5.3              Site-Specific MCEG Peak Ground Acceleration PGAM....................................................... 94

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CHAPTER 22, SEISMIC GROUND MOTION AND LONG-PERIOD TRANSITION MAPS..................... 96

PART 2, COMMENTARY................................................................................................................ 113

COMMENTARY TO CHAPTER 11, SEISMIC DESIGN CRITERIA..................................................... 114

C11.1     GENERAL.................................................................................................................................................... 114

C11.1.1 Purpose........................................................................................................................................... 115

C11.1.2 Scope.............................................................................................................................................. 115

C11.1.3 Applicability.................................................................................................................................. 116

C11.1.4 Alternate Materials and Methods of Construction................................................................. 116

C11.1.5 Quality Assurance........................................................................................................................ 116

C11.2 DEFINITIONS................................................................................................................................................. 117

C11.3 SYMBOLS........................................................................................................................................................ 123

C11.4 SEISMIC GROUND MOTION VALUES.................................................................................................. 124

C11.4.1 Near-Fault Sites............................................................................................................................. 125

C11.4.2 Site Class....................................................................................................................................... 125

C11.4.2.1 Default Site Class................................................................................................... 125

C11.4.3 Risk-Targeted Maximum Considered Earthquake (MCER) Spectral Response Acceleration Parameters...... 126

C11.4.4 Design Spectral Acceleration Parameters................................................................................ 126

C11.4.5 Design Response Spectrum........................................................................................................ 126

C11.4.5.1 Multi-Period Design Response Spectrum......................................................... 126

C11.4.5.2 Two-Period Design Response Spectrum.......................................................... 127

C11.4.6 SITE-SPECIFIC GROUND MOTION PROCEDURES........................................................ 127

C11.5 IMPORTANCE FACTOR AND RISK CATEGORY.............................................................................. 127

C11.5.1 Importance Factor........................................................................................................................ 128

C11.5.2 Protected Access for Risk Category IV.................................................................................... 129

C11.6 SEISMIC DESIGN CATEGORY................................................................................................................. 129

C11.7 DESIGN REQUIREMENTS FOR SEISMIC DESIGN CATEGORY A............................................. 131


C11.8 GEOLOGIC HAZARDS AND GEOTECHNICAL INVESTIGATION............................................... 132

C11.8.1 Site Limitation for Seismic Design Categories E and F........................................................ 132

C11.8.2 Geotechnical Investigation Report Requirements for Seismic Design Categories C through F         132

C11.8.3 Additional Geotechnical Investigation Report Requirements for Seismic Design Categories D through F....... 132

C11.9 VERTICAL GROUND MOTIONS FOR SEISMIC DESIGN................................................................ 134

C11.9.1 General........................................................................................................................................... 134

C11.9.2 MCER Vertical Response Spectrum.......................................................................................... 134

REFERENCES............................................................................................................................................................. 137

OTHER REFERENCES (NOT CITED)................................................................................................................. 138

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COMMENTARY TO CHAPTER 12, SEISMIC DESIGN REQUIREMENTS FOR BUILDING STRUCTURES          140

C12.1     STRUCTURAL DESIGN BASIS............................................................................................................ 140

C12.1.1 Basic Requirements..................................................................................................................... 140

C12.1.2 Member Design, Connection Design, and Deformation Limit............................................ 144

C12.1.3 Continuous Load Path and Interconnection............................................................................ 144

C12.1.4 Connection to Supports............................................................................................................... 144

C12.1.5 Foundation Design........................................................................................................................ 145

C12.1.6 Material Design and Detailing Requirements......................................................................... 145

C12.2 STRUCTURAL SYSTEM SELECTION.................................................................................................... 145

C12.2.1 Seismic Force-Resisting System Selection and Limitations................................................. 145

C12.2.1.1 Alternative Structural Systems........................................................................... 149

C12.2.1.2 Elements of Seismic Force-Resisting Systems................................................ 150

C12.2.2 Combinations of Framing Systems in Different Directions.................................................. 151

C12.2.3 Combinations of Framing Systems in the Same Direction.................................................... 151

C12.2.3.1 R, Cd, and Ω0 Values for Vertical Combinations........................................... 151

C12.2.3.2 Two-Stage Analysis Procedure........................................................................... 151

C12.2.3.3 R, Cd, and Ω0 Values for Horizontal Combinations........................................ 152

C12.2.4 Combination Framing Detailing Requirements...................................................................... 152

C12.2.5 System-Specific Requirements.................................................................................................. 152

C12.2.5.1 Dual System........................................................................................................... 152

C12.2.5.2 Cantilever Column Systems................................................................................ 153

C12.2.5.3 Inverted Pendulum-Type Structures.................................................................. 153

C12.2.5.4 Increased Structural Height Limit for Steel Eccentrically Braced Frames, Steel Special Concentrically Braced Frames, Steel Buckling- Restrained Braced Frames, Steel Special Plate Shear Walls, and   Special Reinforced Concrete Shear Walls................................................... 153

C12.2.5.5 Special Moment Frames in Structures Assigned to Seismic Design Categories D through F............. 153

C12.2.5.6 Steel Ordinary Moment Frames......................................................................... 154

C12.2.5.6.1 Seismic Design Category D or E.................................................................... 155

C12.2.5.6.2 Seismic Design Category F.............................................................................. 156

C12.2.5.7 Steel Intermediate Moment Frames.................................................................. 156

C12.2.5.7.1 Seismic Design Category D............................................................................. 156

C12.2.5.7.2 Seismic Design Category E.............................................................................. 156

C12.2.5.7.3 Seismic Design Category F.............................................................................. 156

C12.2.5.8 Shear Wall–Frame Interactive Systems............................................................ 156

C12.3 DIAPHRAGM FLEXIBILITY, CONFIGURATION IRREGULARITIES, AND

REDUNDANCY........................................................................................................................................... 157

C12.3.1 Diaphragm Flexibility.................................................................................................................. 157

C12.3.1.1 Flexible Diaphragm Condition........................................................................... 157

C12.3.1.2 Rigid Diaphragm Condition................................................................................ 157

C12.3.1.3 Calculated Flexible Diaphragm Condition....................................................... 158

C12.3.2 Irregular and Regular Classification......................................................................................... 158

C12.3.2.1 Horizontal Irregularity.......................................................................................... 158

C12.3.2.2 Vertical Irregularity.............................................................................................. 159

C12.3.3 Limitations and Additional Requirements for Systems with Structural Irregularities...... 161

C12.3.3.1 Prohibited Horizontal and Vertical Irregularities for Seismic Design Categories D through F................ 161

C12.3.3.2 Extreme Weak Stories.......................................................................................... 161

C12.3.3.3 Elements Supporting Discontinuous Walls or Frames................................... 162

C12.3.3.4 Increase in Forces Caused by Irregularities for Seismic Design Categories

D through F....................................................................................................... 163

C12.3.4 Redundancy.................................................................................................................................. 163

C12.3.4.1 Conditions Where Value of ρ is 1.0................................................................... 163

C12.3.4.2 Redundancy Factor, ρ, for Seismic Design Categories D through F............ 164

C12.4 SEISMIC LOAD EFFECTS AND COMBINATIONS............................................................................ 166

C12.4.1 Applicability.................................................................................................................................. 166

C12.4.2 Seismic Load Effect.................................................................................................................... 166

C12.4.2.1 Horizontal Seismic Load Effect......................................................................... 166

C12.4.2.2 Vertical Seismic Load Effect.............................................................................. 167

C12.4.3 Seismic Load Effects Including Overstrength......................................................................... 167

C12.4.3.1 Horizontal Seismic Load Effect Including Overstrength............................... 167

C12.4.3.2 Capacity-Limited Horizontal Seismic Load Effect........................................ 167

C12.4.4 Minimum Upward Force for Horizontal Cantilevers for Seismic Design Categories D through F    168

C12.5 DIRECTION OF LOADING......................................................................................................................... 168

C12.5.1 Direction of Loading Criteria..................................................................................................... 168

C12.5.2 Seismic Design Category B........................................................................................................ 168

C12.5.3 SEISMIC DESIGN CATEGORY C......................................................................................................... 168

C12.5.4 Seismic Design Categories D through F................................................................................... 169

C12.6 ANALYSIS PROCEDURE SELECTION.................................................................................................. 170

C12.7 MODELING CRITERIA............................................................................................................................... 170

C12.7.1 Foundation Modeling................................................................................................................... 170

C12.7.2 Effective Seismic Weight............................................................................................................ 171

C12.7.3 Structural Modeling...................................................................................................................... 171

C12.7.4 Interaction Effects........................................................................................................................ 172

C12.8 EQUIVALENT LATERAL FORCE PROCEDURE................................................................................ 173

C12.8.1 Seismic Base Shear...................................................................................................................... 173

C12.8.1.1 Calculation of Seismic Response Coefficient.................................................. 173

C12.8.1.2 Soil–Structure Interaction Reduction................................................................ 175

C12.8.1.3 Maximum SDS Value in Determination of Cs and Ev....................................... 175

C12.8.2 Period Determination.................................................................................................................. 175

C12.8.2.1 Approximate Fundamental Period..................................................................... 177

C12.8.3 Vertical Distribution of Seismic Forces.................................................................................... 177

C12.8.4 Horizontal Distribution of Forces.............................................................................................. 179

C12.8.4.1 Inherent Torsion.................................................................................................... 179

C12.8.4.2 Accidental Torsion................................................................................................ 180

C12.8.4.3 Amplification of Accidental Torsional Moment............................................. 181

C12.8.5 Overturning.................................................................................................................................... 182

C12.8.6 Displacement and Drift Determination.................................................................................... 182

C12.8.6.1 Minimum Base Shear for Computing Drift...................................................... 185

C12.8.6.2 Period for Computing Drift................................................................................. 185

C12.8.7 P-Delta Effects............................................................................................................................. 186


C12.9 LINEAR DYNAMIC ANALYSIS................................................................................................................ 190

C12.9.1 Modal Response Spectrum Analysis......................................................................................... 190

C12.9.1.1 Number of Modes................................................................................................. 191

C12.9.1.2 Modal Response Parameters............................................................................... 191

C12.9.1.3 Combined Response Parameters........................................................................ 192

C12.9.1.4 Scaling Design Values of Combined Response............................................... 192

C12.9.1.4.1 Scaling of Forces................................................................................................ 192

C12.9.1.4.2 Scaling of Drifts................................................................................................. 193

C12.9.1.5 Horizontal Shear Distribution.............................................................................. 193

C12.9.1.6 P-Delta Effects...................................................................................................... 194

C12.9.1.7 Soil–Structure Interaction Reduction................................................................ 194

C12.9.1.8 Structural Modeling.............................................................................................. 194

C12.9.2 Linear Response History Analysis............................................................................................. 194

C12.9.2.1 General Requirements.......................................................................................... 194

C12.9.2.2 General Modeling Requirements....................................................................... 194

C12.9.2.2.1 P-Delta Effects................................................................................................... 194

C12.9.2.2.2 Accidental Torsion............................................................................................. 195

C12.9.2.2.3 Foundation Modeling........................................................................................ 195

C12.9.2.2.4 Number of Modes to Include in Modal Response History Analysis......... 195

C12.9.2.2.5 Damping.............................................................................................................. 196

C12.9.2.3 Ground Motion Selection and Modification.................................................... 196

C12.9.2.3.1 Procedure for Spectrum Matching.................................................................. 197

C12.9.2.4 Application of Ground Acceleration Histories................................................. 197

C12.9.2.5 Modification of Response for Design................................................................ 197

C12.9.2.6 Enveloping of Force Response Quantities........................................................ 197

C12.10 DIAPHRAGMS, CHORDS, AND COLLECTORS............................................................................... 198

C12.10.1 Diaphragm Design...................................................................................................................... 198

C12.10.1.1 Diaphragm Design Forces................................................................................. 200

C12.10.2.1 Collector Elements Requiring Load Combinations Including

Overstrength for Seismic Design Categories C through F....................... 200

C12.10.3 Alternative Design Provisions for Diaphragms, Including Chords and Collectors........ 200

C12.10.3.1 Design.................................................................................................................... 201

C12.10.3.2 Seismic Design Forces for  Diaphragms,  Including  Chords  and Collectors.             201

C12.10.3.3 Transfer Forces in Diaphragms........................................................................ 205

C12.10.3.4 Collectors—Seismic Design Categories C through F................................... 206

C12.10.3.5 Diaphragm Design Force Reduction Factor................................................... 206

C12.10.4 Alternative Diaphragm Design Provisions for One-Story Structures with Flexible

Wood Structural Panel Diaphragms and Rigid Vertical Elements................................. 214

C12.11 STRUCTURAL WALLS AND THEIR ANCHORAGE....................................................................... 222

C12.11.1 Design for Out-of-Plane Forces............................................................................................... 222

C12.11.2 Anchorage of Structural Walls and Transfer of Design Forces into Diaphragms or

Other Supporting Structural Elements................................................................................. 222

C12.11.2.1 Wall Anchorage Forces...................................................................................... 223

C12.11.2.2 Additional Requirements for Anchorage of Concrete or Masonry Structural Walls to Diaphragms in Structures Assigned to Seismic

Design Categories C through F..................................................................... 223

C12.11.2.2.1 Transfer of Anchorage Forces into Diaphragm.......................................... 223

C12.11.2.2.2 Steel Elements of Structural Wall Anchorage System.............................. 223

C12.11.2.2.3 Wood Diaphragms.......................................................................................... 223

C12.11.2.2.4 Metal Deck Diaphragms................................................................................ 224

C12.11.2.2.5 Embedded Straps............................................................................................. 224

C12.11.2.2.6 Eccentrically Loaded Anchorage System................................................... 225

C12.11.2.2.7 Walls with Pilasters......................................................................................... 225


C12.12 DRIFT AND DEFORMATION.................................................................................................................. 226

C12.12.3 Structural Separation................................................................................................................. 227

C12.12.4 Members Spanning between Structures................................................................................. 228

C12.12.5 Deformation Compatibility for Seismic Design Categories D through F......................... 228

C12.13 FOUNDATION DESIGN............................................................................................................................ 229

C12.13.1 Design Basis................................................................................................................................ 229

C12.13.3 Foundation Load-Deformation Characteristics.................................................................... 229

C12.13.4 Reduction of Foundation Overturning.................................................................................... 230

C12.13.5 Strength Design for Foundation Geotechnical Capacity.................................................... 230

C12.13.5.1.1 Soil Strength Parameters................................................................................ 230

C12.13.5.2 Resistance Factors.............................................................................................. 232

C12.13.5.3 Acceptance Criteria............................................................................................ 232

C12.13.6 Allowable Stress Design for Foundation Geotechnical Capacity..................................... 232

C12.13.7 Requirements for Structures Assigned to Seismic Design Category C............................ 232

C12.13.7.1 Pole-Type Structures.......................................................................................... 232

C12.13.7.2 Foundation Ties................................................................................................... 232

C12.13.7.3 Pile Anchorage Requirements.......................................................................... 233

C12.13.8 Requirements for Structures Assigned to Seismic Design Categories D through F....... 233

C12.13.8.1 Pole-Type Structures.......................................................................................... 233

C12.13.8.2 Foundation Ties................................................................................................... 233

C12.13.8.3 General Pile Design Requirement................................................................... 233

C12.13.8.4 Batter Piles............................................................................................................ 233

C12.13.8.5 Pile Anchorage Requirements.......................................................................... 234

C12.13.8.6 Splices of Pile Segments.................................................................................... 234

C12.13.8.7 Pile–Soil Interaction.......................................................................................... 234

C12.13.8.8 Pile Group Effects.............................................................................................. 234

C12.13.9 Requirements for Foundations on Liquefiable Sites............................................................ 234

C12.13.9.1 Foundation Design.............................................................................................. 236

C12.13.9.2 Shallow Foundations......................................................................................... 236

C12.13.9.3 Deep Foundations............................................................................................... 237

C12.14 SIMPLIFIED ALTERNATIVE STRUCTURAL DESIGN CRITERIA FOR SIMPLE

BEARING WALL OR BUILDING FRAME SYSTEMS.................................................................... 239

C12.14.1 General......................................................................................................................................... 239

C12.14.1.1 Simplified Design Procedure............................................................................ 239

C12.14.3 Seismic Load Effects and Combinations.............................................................................. 240

C12.14.7 DESIGN AND DETAILING REQUIREMENTS................................................................................ 241

C12.14.8 SIMPLIFIED LATERAL FORCE ANALYSIS PROCEDURE........................................................ 241

C12.14.8.1 Seismic Base Shear............................................................................................ 241

C12.14.8.2 Vertical Distribution........................................................................................... 241

C12.14.8.5 Drift Limits and Building Separation............................................................. 241

REFERENCES............................................................................................................................................................. 241

OTHER REFERENCES (NOT CITED)................................................................................................................. 246

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COMMENTARY TO CHAPTER 13, SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONENTS..... 248

C13.1     GENERAL.................................................................................................................................................... 248

C13.1.1 Scope.............................................................................................................................................. 251

C13.1.2 Seismic Design Category............................................................................................................ 252

C13.1.3 Component Importance Factor.................................................................................................. 253

C13.1.4 Exemptions.................................................................................................................................... 253

C13.1.5 Premanufactured Modular Mechanical and Electrical Systems........................................... 255

C13.1.6 Application of Nonstructural Component Requirements to Nonbuilding Structures....... 255


C13.1.7 Reference Documents................................................................................................................. 256

C13.1.8 Reference Documents Using Allowable Stress Design.......................................................... 256

C13.2 GENERAL DESIGN REQUIREMENTS................................................................................................... 257

C13.2.1 Applicable Requirements for Architectural, Mechanical, and Electrical Components, Supports, and Attachments......... 257

C13.2.2 Special Certification Requirements for Designated Seismic Systems................................ 257

C13.2.3 Consequential Damage............................................................................................................... 258

C13.2.4 Flexibility........................................................................................................................................ 259

C13.2.5 Testing Alternative for Seismic Capacity Determination..................................................... 260

C13.2.6 Experience Data Alternative for Seismic Capacity Determination..................................... 261

C13.2.7 Construction Documents............................................................................................................ 262

C13.2.8 Supported Nonstructural Components with Greater Than or Equal to 20% Combined Weight.        262

C13.3 SEISMIC DEMANDS ON NONSTRUCTURAL COMPONENTS...................................................... 262

C13.3.1 Seismic Design Force.................................................................................................................. 262

C13.3.1.1 Amplification with Height, Hf............................................................................. 266

C13.3.1.5 Nonlinear Response History Analysis............................................................... 266

C13.3.2 Seismic Relative Displacements................................................................................................ 267

C13.3.2.1 Displacements within Structures........................................................................ 267

C13.3.2.2 Displacements between Structures..................................................................... 268

C13.3.3 Component Period........................................................................................................................ 269

C13.4 NONSTRUCTURAL COMPONENT ANCHORAGE............................................................................. 269

C13.4.1 Design Force in the Attachment................................................................................................ 270

C13.4.2 Anchors in Concrete or Masonry.............................................................................................. 270

C13.4.3 Installation Conditions................................................................................................................ 272

C13.4.4 Multiple Attachments................................................................................................................. 272

C13.4.5 Power-Actuated Fasteners.......................................................................................................... 272

C13.4.6 Friction Clips................................................................................................................................. 272

C13.5 ARCHITECTURAL COMPONENTS......................................................................................................... 273

C13.5.1 General........................................................................................................................................... 273

C13.5.2 Forces and Displacements.......................................................................................................... 274

C13.5.3 Exterior Nonstructural Wall Elements and Connections...................................................... 274

C13.5.4 Glass................................................................................................................................................ 275

C13.5.5 Out-of-Plane Bending.................................................................................................................. 276

C13.5.6 Suspended Ceilings....................................................................................................................... 276

C13.5.6.1 Seismic Forces....................................................................................................... 277

C13.5.6.2 Industry Standard Construction for Acoustical Tile or Lay-In Panel  Ceilings.              277

C13.5.6.2.1 Seismic Design Category C............................................................................. 283

C13.5.6.2.2 Seismic Design Categories D through F........................................................ 283

C13.5.6.3 Integral Construction............................................................................................ 284

C13.5.7 Access Floors................................................................................................................................. 284

C13.5.7.1 General.................................................................................................................... 284

C13.5.7.2 Special Access Floors........................................................................................... 284

C13.5.8 Partitions........................................................................................................................................ 285

C13.5.9 Glass in Glazed Curtain Walls, Glazed Storefronts, and Glazed Partitions....................... 285

C13.5.9.1 General.................................................................................................................... 285

C13.5.9.2 Seismic Drift Limits for Glass Components.................................................... 285

C13.5.10 Egress Stairs and Ramps.......................................................................................................... 286

C13.5.11 Penthouses and Rooftop Structures........................................................................................ 286

C13.6 MECHANICAL AND ELECTRICAL COMPONENTS.......................................................................... 287

C13.6.1 General........................................................................................................................................... 288

C13.6.2 Mechanical Components and C13.6.3 Electrical Components............................................ 288

C13.6.4 Component Supports................................................................................................................... 291

Figure C13.6.4.4 Example of a distribution system support for piping. (FEMA E-      74)            294

C13.6.4.1 Design Basis........................................................................................................... 294

C13.6.4.2 Design for Relative Displacement..................................................................... 295

C13.6.4.3 Support Attachment to Component................................................................... 295

C13.6.4.5 Additional Requirements..................................................................................... 295

C13.6.5 Distribution Systems: Conduit, Cable Tray, and Raceways................................................. 296

C13.6.6 Distribution Systems: Duct Systems..................................................................... 296

C13.6.7 Distribution Systems: Piping and Tubing Systems................................................................ 296

C13.6.7.1 ASME Pressure Piping Systems......................................................................... 298

C13.6.7.2 Fire Protection Sprinkler Piping Systems......................................................... 298

C13.6.7.3 Exceptions.............................................................................................................. 299

C13.6.9 Utility and Service Lines............................................................................................................. 299

C13.6.10 Boilers and Pressure Vessels.................................................................................................... 299

C13.6.11 Elevator and Escalator Design Requirements....................................................................... 299

C13.6.11.3 Seismic Controls for Elevators......................................................................... 299

C13.6.11.4 Retainer Plates..................................................................................................... 300

C13.6.12 Rooftop Solar Panels................................................................................................................. 300

C13.6.13 Other Mechanical and Electrical Components..................................................................... 300

REFERENCES............................................................................................................................................................. 301

OTHER REFERENCES (NOT CITED)................................................................................................................. 303

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COMMENTARY TO CHAPTER 14, MATERIAL-SPECIFIC SEISMIC DESIGN AND DETAILING REQUIREMENTS..... 306

C14.0 SCOPE............................................................................................................................................................... 306

C14.1 STEEL............................................................................................................................................................... 306

C14.1.1 Reference Documents................................................................................................................. 306

C14.1.2 Structural Steel.............................................................................................................................. 306

C14.1.2.1 General.................................................................................................................... 306

C14.1.2.2 Seismic Requirements for Structural Steel Structures.................................... 306

C14.1.2.2.1 Seismic Design Categories B and C............................................................... 306

C14.1.2.2.2 Seismic Design Categories D through F........................................................ 307

C14.1.3 COLD-FORMED STEEL........................................................................................................................... 307

C14.1.3.1 General.................................................................................................................... 307

C14.1.3.2 Seismic Requirements for Cold-Formed Steel Structures.............................. 307

C14.1.4 Cold-Formed Steel Light-Frame Construction....................................................................... 307

C14.1.4.1 General.................................................................................................................... 307

C14.1.4.2 Seismic Requirements for Cold-Formed Steel Light-Frame Construction. 308 C14.1.4.3 Prescriptive Cold-Formed Steel Light-Frame Construction..... 308

C14.1.5 Cold-Formed Steel Deck Diaphragms...................................................................................... 308

C14.1.7 Steel Cables................................................................................................................................... 312

C14.1.8 Additional Detailing Requirements for Steel Piles in Seismic Design Categories D through F         312

C14.2 CONCRETE..................................................................................................................................................... 312

C14.2.2.1 Definitions.............................................................................................................. 312

C14.2.2.2 ACI 318, Section 10.7.6...................................................................................... 313

C14.2.2.3 Scope....................................................................................................................... 313

C14.2.2.4 Intermediate Precast Structural Walls................................................................ 313

C14.2.2.6 Foundations........................................................................................................... 313

C14.2.2.7 Detailed Plain Concrete Shear Walls................................................................. 313

C14.2.3 Additional Detailing Requirements for Concrete Piles.......................................................... 313

C14.2.3.1.2 Reinforcement for Uncased Concrete Piles (SDC C).................................. 314


C14.2.3.1.5 Reinforcement for Precast Nonprestressed Piles (SDC C)......................... 314

C14.2.3.1.6 Reinforcement for Precast Prestressed Piles (SDC C)................................ 314

C14.2.3.2.3 Reinforcement for Uncased Concrete Piles (SDC D through F)............... 314

C14.2.3.2.5 Reinforcement for Precast Nonprestressed Piles (SDC D through F)...... 314

C14.2.3.2.6 Reinforcement for Precast Prestressed Piles (SDC D through F).............. 314

C14.2.4 Additional Design and Detailing Requirements for Precast Concrete Diaphragms......... 315

C14.2.4.1 Diaphragm Seismic Demand Levels.................................................................. 315

C14.2.4.2 Diaphragm Design Options................................................................................. 317

C14.2.4.3 Diaphragm Connector or Joint Reinforcement Deformability...................... 320

C14.2.4.3.5 Deformed Bar Reinforcement......................................................................... 321

C14.2.4.3.6 Special Inspection............................................................................................. 321

C14.2.4.4 Precast Concrete Diaphragm Connector and Joint Reinforcement Qualification Procedure..... 321

C14.2.4.4.1 Test Modules...................................................................................................... 321

C14.2.4.4.3 Test Configuration............................................................................................ 321

C14.2.4.4.4 Instrumentation................................................................................................. 322

C14.2.4.4.5 Loading Protocols.............................................................................................. 322

C14.2.4.4.6 Measurement Indices, Test Observations, and Acquisition of Data......... 323

C14.2.4.4.7 Response Properties........................................................................................... 323

C14.2.4.4.8 Test Report......................................................................................................... 324

C14.3 COMPOSITE STEEL AND CONCRETE STRUCTURES.................................................................... 324

C14.3.1 Reference Documents................................................................................................................. 324

C14.3.4 Metal-Cased Concrete Piles........................................................................................................ 325

C14.3.5 Seismic Requirements for Coupled Composite Plate Shear Walls --Concrete Filled

(CC-PSW/CF)........................................................................................................................... 325

C14.3.5.1 Scope....................................................................................................................... 325

C14.3.5.2 Basis of Design...................................................................................................... 326

C14.3.5.3 Analysis................................................................................................................... 326

C14.3.5.3.1 Elastic Analysis.................................................................................................. 329

C14.3.5.3.4. Capacity-Limited Analysis............................................................................. 329

C14.3.5.4 Composite Wall Requirements........................................................................... 330

C14.3.5.4.1 Minimum Area of Steel..................................................................................... 330

C14.3.5.4.2 Slenderness Requirement................................................................................... 330

C14.3.5.4.3 Tie Spacing Requirement for Composite Walls........................................... 330

C14.3.5.4.4 Tie-to-Plate Connection................................................................................... 331

C14.3.5.5 Composite Coupling Beam Requirements....................................................... 332

C14.3.5.5.1 Minimum Area of Steel..................................................................................... 332

C14.3.5.5.2 Slenderness Requirement for Coupling Beams........................................... 332

C14.3.5.6 Composite Wall Strength..................................................................................... 332

C14.3.5.5.4 In-Plane Shear Strength.................................................................................... 332

C14.3.5.5 Nominal vs. Expected Flexural Capacity......................................................... 333

C14.3.5.6 Composite Coupling Beam Strength................................................................. 333

C14.3.5.8 Coupling Beam-to-Wall Connections............................................................... 334

C14.3.5.9 Composite Wall-to-Foundation Connections.................................................. 336

C14.3.5.10 Protected Zones................................................................................................... 337

C14.3.5.11 Demand Critical Welds...................................................................................... 337

C14.4 MASONRY....................................................................................................................................................... 338

C14.5 WOOD............................................................................................................................................................... 338

C14.5.1 Reference Documents................................................................................................................. 338

C14.5.2  Seismic Requirements for Cross Laminated Timber Shear Walls...................................... 338

C14.5.2.1 Scope....................................................................................................................... 338

C14.5.2.2 Application Requirements................................................................................... 339

C14.5.2.3 CLT Shear Wall Requirements.......................................................................... 340

C14.5.2.3.6 Other Load Path Connections to CLT Wall Panels..................................... 344


C14.5.2.3.7 CLT Shear Walls with Shear Resistance Provided by High Aspect

Ratio Panels Only............................................................................................ 345

C14.5.2.4 Shear Wall Deflection.......................................................................................... 345

C14.5.2.7 Diaphragm Requirements.................................................................................... 347

REFERENCES............................................................................................................................................................. 352

OTHER REFERENCES (NOT CITED)................................................................................................................. 355

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COMMENTARY TO CHAPTER 15, SEISMIC DESIGN REQUIREMENTS FOR NONBUILDING STRUCTURES  360

C15.1     GENERAL.................................................................................................................................................... 360

C15.1.1      Nonbuilding Structures........................................................................................................... 360

C15.1.2 Design............................................................................................................................................. 361

C15.1.3 Structural Analysis Procedure Selection................................................................................... 361

C15.1.4 Nonbuilding Structures Sensitive to Vertical Ground Motions........................................... 367

C15.2 NONBUILDING STRUCTURES CONNECTED BY NONSTRUCTURAL

COMPONENTS TO OTHER ADJACENT STRUCTURES.............................................................. 368

C15.2.1 Nonbuilding Structures Connected by Nonstructural Components to Other Adjacent Structures     368

C15.2.2 Architectural, Mechanical, and Electrical Components Spanning Between

Nonbuilding Structures........................................................................................................... 369

C15.3 NONBUILDING STRUCTURES SUPPORTED BY OTHER STRUCTURES................................. 369

C15.3.1 Supported Nonbuilding Structures with Less Than 20% Combined Weight..................... 369

C15.3.2  Supported Nonbuilding Structures with Greater Than or Equal to 20% Combined  Weight.             371

C15.4 STRUCTURAL DESIGN REQUIREMENTS........................................................................................... 372

C15.4.1 Design Basis.................................................................................................................................. 372

C15.4.1.1 Importance Factor................................................................................................ 374

C15.4.2 Rigid Nonbuilding Structures..................................................................................................... 374

C15.4.3 Loads.............................................................................................................................................. 374

C15.4.4 Fundamental Period..................................................................................................................... 374

C15.4.7 Drift, Deflection, and Structure Separation............................................................................. 375

C15.4.8 Site-Specific Response Spectra................................................................................................. 375

C15.4.9 Anchors in Concrete or Masonry.............................................................................................. 375

C15.4.9.4 ASTM F1554 Anchors............................................................................................................. 375

C15.4.10 Requirements for Nonbuilding Structure Foundations on Liquefiable Sites................... 375

C15.5 NONBUILDING STRUCTURES SIMILAR TO BUILDINGS............................................................. 375

C15.5.1 General........................................................................................................................................... 375

C15.5.2 Pipe Racks..................................................................................................................................... 376

C15.5.3.1 Steel Storage Racks.............................................................................................. 376

C15.5.3.2 Steel Cantilevered Storage Racks...................................................................... 377

C15.5.4 Electrical Power-Generating Facilities...................................................................................... 378

C15.5.5 Structural Towers for Tanks and Vessels................................................................................. 378

C15.5.6 Piers and Wharves........................................................................................................................ 379

C15.6 GENERAL REQUIREMENTS FOR NONBUILDING STRUCTURES NOT SIMILAR TO BUILDINGS     380

C15.6.1 Earth-Retaining Structures.......................................................................................................... 380

C15.6.2 Chimneys and Stacks.................................................................................................................. 380

C15.6.2.1 General.................................................................................................................... 380

C15.6.2.2 Concrete Chimneys and Stacks.......................................................................... 380

C15.6.2.3 Steel Chimneys and Stacks................................................................................. 381

C15.6.4 Special Hydraulic Structures...................................................................................................... 381

C15.6.5 Secondary Containment Systems.............................................................................................. 381


C15.6.5.1 Freeboard............................................................................................................... 382

C15.6.6 Telecommunication Towers....................................................................................................... 382

C15.6.7 Steel Tubular Support Structures for Onshore Wind Turbine Generator Systems........... 382

C15.6.8 Ground-Supported Cantilever Walls or Fences...................................................................... 383

C15.7 TANKS AND VESSELS............................................................................................................................... 384

C15.7.1 General........................................................................................................................................... 384

C15.7.2 Design Basis................................................................................................................................. 385

C15.7.3 Strength and Ductility................................................................................................................. 387

C15.7.4 Flexibility of Piping Attachments............................................................................................. 387

C15.7.5 Anchorage..................................................................................................................................... 388

C15.7.6 Ground-Supported Storage Tanks for Liquids........................................................................ 388

C15.7.6.1 General................................................................................................................... 388

C15.7.6.1.1 Distribution of Hydrodynamic and Inertia Forces....................................... 389

C15.7.6.1.2 Sloshing............................................................................................................... 389

C15.7.6.1.4 Internal Elements............................................................................................... 390

C15.7.6.1.5 Sliding Resistance............................................................................................. 390

C15.7.6.1.6 Local Shear Transfer......................................................................................... 391

C15.7.6.1.7 Pressure Stability............................................................................................... 391

C15.7.6.1.8 Shell Support...................................................................................................... 391

C15.7.6.1.9 Repair, Alteration, or Reconstruction............................................................ 391

C15.7.7 Water Storage and Water Treatment Tanks and Vessels...................................................... 391

C15.7.7.1 Welded Steel.......................................................................................................... 392

C15.7.7.2 Bolted Steel............................................................................................................ 392

C15.7.7.3 Reinforced and Prestressed Concrete................................................................ 392

C15.7.8 Petrochemical and Industrial Tanks and Vessels Storing Liquids....................................... 392

C15.7.8.1 Welded Steel.......................................................................................................... 392

C15.7.8.2 Bolted Steel............................................................................................................ 393

C15.7.9 Ground-Supported Storage Tanks for Granular Materials.................................................... 393

C15.7.9.1 General................................................................................................................... 393

C15.7.9.2 Lateral Force Determination............................................................................... 393

C15.7.9.3 Force Distribution to Shell and Foundation..................................................... 393

C15.7.9.3.1 Increased Lateral Pressure............................................................................... 393

C15.7.9.3.2 Effective Mass................................................................................................... 394

C15.7.9.3.3 Effective Density............................................................................................... 394

C15.7.9.3.4 Lateral Sliding................................................................................................... 394

C15.7.9.3.5 Combined Anchorage Systems....................................................................... 394

C15.7.10 Elevated Tanks and Vessels for Liquids and Granular Materials..................................... 394

C15.7.10.1 General................................................................................................................. 394

C15.7.10.4 Transfer of Lateral Forces into Support Tower............................................. 401

C15.7.10.5 Evaluation of Structures Sensitive to Buckling Failure............................... 401

C15.7.10.7 Concrete Pedestal (Composite) Tanks............................................................ 401

C15.7.11 Boilers and Pressure Vessels................................................................................................... 402

C15.7.12 Liquid and Gas Spheres............................................................................................................ 402

C15.7.13 Refrigerated Gas Liquid Storage Tanks and Vessels.......................................................... 402

C15.7.14 Horizontal, Saddle-Supported Vessels for Liquid or Vapor Storage................................ 402

C15.8 CONSENSUS STANDARDS AND OTHER REFERENCED DOCUMENTS................................. 402

REFERENCES............................................................................................................................................................ 403

OTHER REFERENCES (NOT CITED)................................................................................................................. 406

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COMMENTARY TO CHAPTER 16, SEISMIC RESPONSE HISTORY PROCEDURES....................... 407

C16.1     GENERAL REQUIREMENTS................................................................................................................ 407

C16.1.1 Scope.............................................................................................................................................. 407

C16.1.2. Linear Analysis........................................................................................................................... 408


C16.1.3 Vertical Response Analysis........................................................................................................ 408

C16.1.4 Documentation............................................................................................................................. 409

C16.2 GROUND MOTIONS..................................................................................................................................... 409

C16.2.1 Target Response Spectrum......................................................................................................... 409

C16.2.2 Ground Motion Selection............................................................................................................ 411

C16.2.3 Ground Motion Modification..................................................................................................... 413

C16.2.3.1 Period Range for Scaling or Matching.............................................................. 414

C16.2.3.2 Amplitude Scaling................................................................................................. 414

C16.2.3.3 Spectral Matching................................................................................................. 415

C16.2.4 Application of Ground Motions to the Structural Model...................................................... 415

C16.3 MODELING AND ANALYSIS.................................................................................................................... 416

C16.3.1 Modeling........................................................................................................................................ 416

C16.3.3 P-Delta Effects............................................................................................................................. 418

C16.3.4 Torsion........................................................................................................................................... 418

C16.3.5 Damping......................................................................................................................................... 419

C16.3.6 Explicit Foundation Modeling................................................................................................... 419

C16.4.1 Global Acceptance Criteria......................................................................................................... 420

C16.4.1.1 Unacceptable Response....................................................................................... 420

C16.4.1.2 Story Drift............................................................................................................... 424

C16.4.2 Element-Level Acceptance Criteria.......................................................................................... 425

C16.4.2.1 Force-Controlled Actions.................................................................................... 426

C16.4.2.2 Deformation-Controlled Actions........................................................................ 431

C16.4.2.3 Elements of the Gravity Force-Resisting System............................................ 434

REFERENCES............................................................................................................................................................. 434

OTHER REFERENCES (NOT CITED)................................................................................................................. 435

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COMMENTARY TO CHAPTER 17, SEISMIC DESIGN REQUIREMENTS FOR SEISMICALLY ISOLATED STRUCTURES.... 436

C17.1     GENERAL.................................................................................................................................................... 436

C17.2 GENERAL DESIGN REQUIREMENTS................................................................................................... 438

C17.2.4 Isolation System........................................................................................................................... 440

C17.2.4.1 Environmental Conditions................................................................................... 440

C17.2.4.2 Wind Forces........................................................................................................... 440

C17.2.4.3 Fire Resistance...................................................................................................... 440

C17.2.4.4 Lateral Restoring Force........................................................................................ 440

C17.2.4.5 Displacement Restraint........................................................................................ 441

C17.2.4.6 Vertical-Load Stability......................................................................................... 441

C17.2.4.7 Overturning............................................................................................................. 441

C17.2.4.8 Inspection and Replacement.............................................................................. 441

C17.2.4.9 Quality Control...................................................................................................... 441

C17.2.5 Structural System......................................................................................................................... 442

C17.2.5.2 Minimum Building Separations......................................................................... 442

C17.2.5.4 Steel Ordinary Concentrically Braced Frames................................................ 442

C17.2.5.5 Isolation System Connections............................................................................ 443

C17.2.6 Elements of Structures and Nonstructural Components....................................................... 443

C17.2.8 Isolation System Properties......................................................................................................... 447

C17.2.8.2 Isolator Unit Nominal Properties........................................................................ 447

C17.2.8.3 Bounding Properties of Isolation System Components................................. 448

C17.2.8.4 Property Modification Factors............................................................................ 449

C17.2.8.5 Upper Bound and Lower Bound Force-Deflection Behavior of Isolation System Components.......... 455

C17.3 SEISMIC GROUND MOTION CRITERIA.............................................................................................. 455


C17.3.1 Site-Specific Seismic Hazard.................................................................................................... 455

C17.3.3 MCER Ground Motion Records................................................................................................. 455

C17.4 ANALYSIS PROCEDURE SELECTION.................................................................................................. 456

C17.5 EQUIVALENT LATERAL FORCE PROCEDURE................................................................................ 457

C17.5.3 Minimum Lateral Displacements Required for Design.......................................................... 457

C17.5.3.1 Maximum Displacement..................................................................................... 457

C17.5.3.2 Effective Period at the Maximum Displacement............................................ 457

C17.5.3.3 Total Maximum Displacement........................................................................... 457

C17.5.4 Minimum Lateral Forces Required for Design........................................................................ 458

C17.5.4.1 Isolation System and Structural Elements below the Base Level................. 461

C17.5.4.2 Structural Elements above the Base Level....................................................... 461

C17.5.4.3 Limits on Vs............................................................................................................ 461

C17.5.5 Vertical Distribution of Force.................................................................................................... 462

C17.5.6 Drift Limits.................................................................................................................................... 465

C17.6 DYNAMIC ANALYSIS PROCEDURES................................................................................................... 465

C17.6.2 Modeling........................................................................................................................................ 467

C17.6.3.4 Response History Analysis Procedure............................................................... 467

C17.7 DESIGN REVIEW.......................................................................................................................................... 468

C17.8 TESTING.......................................................................................................................................................... 468

C17.8.2.2 Sequence and Cycles............................................................................................ 468

C17.8.2.3 Dynamic Testing................................................................................................... 469

C17.8.2.4 Units Dependent on Bilateral Load................................................................... 470

C17.8.2.5 Maximum and Minimum Vertical Load........................................................... 470

C17.8.2.7 Testing Similar Units............................................................................................ 470

C17.8.3 Determination of Force-Deflection Characteristics................................................................ 471

C17.8.4 Test Specimen Adequacy........................................................................................................... 472

C17.8.5 Production Tests........................................................................................................................... 473

REFERENCES............................................................................................................................................................. 473

OTHER REFERENCES (NOT CITED)................................................................................................................. 475

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COMMENTARY TO CHAPTER 18, SEISMIC DESIGN REQUIREMENTS FOR STRUCTURES WITH DAMPING SYSTEMS....... 478

C18.1     GENERAL.................................................................................................................................................... 478

C18.2 GENERAL DESIGN REQUIREMENTS................................................................................................... 478

C18.2.1 System Requirements.................................................................................................................. 478

C18.2.1.2 Damping System................................................................................................... 479

C18.2.2 Seismic Ground Motion Criteria................................................................................................ 479

C18.2.3 Procedure Selection...................................................................................................................... 479

C18.2.4.1 Device Design........................................................................................................ 480

C18.2.4.4 Nominal Design Properties.................................................................................. 482

C18.2.4.5 Maximum and Minimum Damper Properties Specification Tolerance on Nominal Design Properties........... 482

C18.2.4.6 Damping System Redundancy........................................................................... 484

C18.3 NONLINEAR RESPONSE HISTORY PROCEDURE............................................................................ 484

C18.3.2 Accidental Mass Eccentricity..................................................................................................... 485

C18.4 SEISMIC LOAD CONDITIONS AND ACCEPTANCE CRITERIA FOR NONLINEAR RESPONSE HISTORY PROCEDURE........... 486

C18.4.1 Seismic Force-Resisting System................................................................................................ 486

C18.5 DESIGN REVIEW.......................................................................................................................................... 487


C18.6 TESTING.......................................................................................................................................................... 487

C18.6.1.2 Sequence and Cycles of Testing......................................................................... 487

C18.6.1.3 Testing Similar Devices....................................................................................... 487

C18.6.1.4 Determination of Force-Velocity-Displacement Characteristics.................. 487

C18.6.2 Production Tests........................................................................................................................... 487

C18.7 ALTERNATE PROCEDURES AND CORRESPONDING ACCEPTANCE CRITERIA............... 488

C18.7.1 Response-Spectrum Procedure and C18.7.2 Equivalent Lateral Force Procedure............ 488

C18.7.3 Damped Response Modification............................................................................................... 491

C18.7.3.1 Damping Coefficient............................................................................................ 491

C18.7.3.2 Effective Damping................................................................................................ 492

C18.7.4 Seismic Load Conditions and Acceptance Criteria for RSA and ELF Procedures            492

C18.7.4.5 Seismic Load Conditions and Combination of Modal Responses............... 492

REFERENCES............................................................................................................................................................. 492

OTHER REFERENCES (NOT CITED)................................................................................................................. 493

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COMMENTARY TO CHAPTER 19, SOIL-STRUCTURE INTERACTION FOR SEISMIC DESIGN....... 495

C19.1 GENERAL........................................................................................................................................................ 495

C19.2 SSI ADJUSTED STRUCTURAL DEMANDS.......................................................................................... 496

C19.3 FOUNDATION DAMPING EFFECTS...................................................................................................... 499

C19.4 KINEMATIC SSI EFFECTS......................................................................................................................... 501

C19.4.1 Base Slab Averaging.................................................................................................................... 502

C19.4.2 Embedment................................................................................................................................... 503

REFERENCES............................................................................................................................................................. 503

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COMMENTARY TO CHAPTER 20, SITE CLASSIFICATION PROCEDURE FOR SEISMIC DESIGN . 506

C20.1     SITE CLASSIFICATION.......................................................................................................................... 506

C20.2 SITE CLASS DEFINITIONS........................................................................................................................ 506

C20.2.1 Site Class F.................................................................................................................................... 506

C20.3 ESTIMATION OF SHEAR WAVE VELOCITY PROFILES................................................................ 507

C20.4 DEFINITIONS OF SITE CLASS PARAMETERS................................................................................... 512

REFERENCES............................................................................................................................................................. 512

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COMMENTARY TO CHAPTER 21, SITE-SPECIFIC GROUND MOTION PROCEDURES FOR SEISMIC DESIGN 514

C21.0     GENERAL.................................................................................................................................................... 514

C21.1 SITE RESPONSE ANALYSIS...................................................................................................................... 515

C21.1.1 Base Ground Motions.................................................................................................................. 515

C21.1.2 Site Condition Modeling............................................................................................................. 515

C21.1.3 Site Response Analysis and Computed Results...................................................................... 516

C21.2 RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND

MOTION HAZARD ANALYSIS............................................................................................................. 516

C21.2.1 Probabilistic (MCER) Ground Motions.................................................................................... 516

C21.2.2 Deterministic (MCER) Ground Motions................................................................................... 517

C21.2.3 Site-Specific MCER..................................................................................................................... 518

C21.3 DESIGN RESPONSE SPECTRUM............................................................................................................. 519


C21.4 DESIGN ACCELERATION PARAMETERS........................................................................................... 519

C21.5 MAXIMUM CONSIDERED EARTHQUAKE GEOMETRIC MEAN (MCEG) PEAK

GROUND ACCELERATION................................................................................................................... 520

REFERENCES............................................................................................................................................................. 520

OTHER REFERENCES (NOT CITED)................................................................................................................. 522

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COMMENTARY TO CHAPTER 22, SEISMIC GROUND MOTION AND LONG-PERIOD TRANSITION MAPS     524

RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) SPECTRAL

RESPONSE ACCELERATIONS............................................................................................................. 539

MAXIMUM CONSIDERED EARTHQUAKE GEOMETRIC MEAN (MCEG) PEAK GROUND ACCELERATIONS.......... 541

LONG-PERIOD TRANSITION MAPS.................................................................................................................. 541

USGS SEISMIC DESIGN GEODATABASE AND WEB SERVICE.............................................................. 542

REFERENCES............................................................................................................................................................. 542

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APPENDIX PROJECT PARTICIPANTS........................................................................................... 546


intentionally left blank.

 

2020 NEHRP RECOMMENDED SEISMIC PROVISIONS FOR NEW BUILDINGS AND OTHER STRUCTURES

 

APPENDIX PROJECT PARTICIPANTS

 

BSSC Provisions Update Committee

 

 

Chair

David Bonneville

Degenkolb Engineers

Voting Member

Peter Carrato

Bechtel Power Corporation

Voting Member

Kelly Cobeen

Wiss, Janney, Elstner Associates

Voting Member

C.B. Crouse

AECOM

Voting Member

Dan Dolan

Washington State University

Voting Member

Anindya Dutta

Simpson Gumpertz & Heger

Voting Member

S.K. Ghosh

S.K. Ghosh Associates

Voting Member

John Gillengerten

SE, Retired OSHPD

Voting Member

Ron Hamburger

Simpson Gumpertz & Heger

Voting Member

Jim Harris

James Harris & Associates

Voting Member

William Holmes

Rutherford + Chekene

Voting Member

John Hooper

Magnusson Klemencic Associates

Voting Member

Gyimah Kasali

Rutherford + Chekene

Voting Member

Charles Kircher

Charles Kircher & Associates

Voting Member

Philip Line

American Wood Council

Voting Member

Bret Lizundia

Rutherford + Chekene

Voting Member

James Malley

Degenkolb Engineers

Voting Member

Bonnie Manley

American Iron and Steel Institute

Voting Member

Robert Pekelnicky

Degenkolb Engineers

Voting Member

Rafael Sabelli

Walter P. Moore

Voting Member

John Silva

Hilti

Voting Member

J. G. (Greg) Soules

CB&I Storage Tank Solutions

Voting Member

Jonathan Stewart

University of California, Los Angeles

FEMA technical advisor

and representative

 

Robert Hanson

 

University of Michigan (Professor Emeritus)

FEMA representative

Mai Tong

Federal Emergency Management Agency

USGS representative

Nicolas Luco

U.S. Geological Survey

USGS representative

Sanaz Rezaeian

U.S. Geological Survey

NIST representative

Steven McCabe

National Institute of Standards and Technology

NIST representative

Matthew Speicher

National Institute of Standards and Technology

NIBS Staff

Jiqiu (JQ) Yuan

National Institute of Building Sciences

 

BSSC Project 17 Committee on Seismic Design Value Maps

 

 

Chair

Ron Hamburger

Simpson Gumpertz & Heger

Voting Member

Norm Abrahamson

University of California Berkeley

Voting Member

David Bonneville

Degenkolb Engineers

Voting Member

C.B. Crouse

AECOM

Voting Member

Dan Dolan

Washington State University

Voting Member

Julie Furr

Rimkus Consulting Group

Voting Member

Jim Harris

James Harris & Associates

Voting Member

Jon Heintz

Applied Technology Council

Voting Member

William Holmes

Rutherford + Chekene

Voting Member

John Hooper

Magnusson Klemencic Associates

Voting Member

Charles Kircher

Charles Kircher & Associates

Voting Member

Robert Pekelnicky

Degenkolb Engineers

Voting Member

Jon Siu

City of Seattle, Washington

Voting Member

Jonathan Stewart

University of California, Los Angeles

USGS representative

Nicolas Luco

U.S. Geological Survey

USGS representative

Sanaz Rezaeian

U.S. Geological Survey

FEMA technical advisor and representative

Robert Hanson

 

University of Michigan (Professor Emeritus)

FEMA representative

Mai Tong

Federal Emergency Management Agency

NIST representative

Steven McCabe

National Institute of Standards and Technology

NIST representative

Siamak Sattar

National Institute of Standards and Technology

NIBS Staff

Jiqiu (JQ) Yuan

National Institute of Building Sciences

 

PUC Issue Teams

 

 

IT 1, Seismic Performance Objectives

Chair

Robert Pekelnicky

Degenkolb Engineers

Voting Member

Ibbi Amufti

Arup

Voting Member

David Bonneville

Degenkolb Engineers

Voting Member

Julie Furr

Rimkus Consulting Group

Voting Member

Ron Hamburger

Simpson Gumpertz & Heger

Voting Member

Jim Harris

James Harris & Associates

Voting Member

Jon Heintz

Applied Technology Council

Voting Member

John Hooper

Magnusson Klemencic Associates

 

Voting Member

 

Steven McCabe

National Institute of Standards and

Technology

Voting Member

Maryann Phipps

Estructure

Voting Member

John Silva

Hilti

Voting Member

J. G. (Greg) Soules

CB&I Storage Tank Solutions

Corresponding Member

David Bonowitz

David Bonowitz, S.E.

Corresponding Member

Dan Dolan

Washington State University

Corresponding Member

John Gillengerten

SE, Retired OSHPD

Corresponding Member

Philip Line

American Wood Council

Corresponding Member

Nicolas Luco

U.S. Geological Survey

Corresponding Member

Terry Lundeen

Coughlin Porter Lundeen

Corresponding Member

Kevin Moore

Simpson Gumpertz & Heger

Corresponding Member

Rob Smith

Arup

Corresponding Member

Jeffrey Soulages

Intel Corporation

IT 2, Seismic-Force Resisting Systems and Design Coefficients

Chair

Conrad "Sandy" Hohener

Degenkolb Engineers

Voting Member

Dan Dolan

Washington State University

Voting Member

Edwin Huston

Smith & Huston

Voting Member

Bret Lizundia

Rutherford + Chekene

Voting Member

Kevin Moore

Simpson Gumpertz & Heger

Voting Member

Tom Xia

DCI Engineers

Corresponding Member

Richard Bennett

University of Tennessee

Corresponding Member

Hussain Bhatia

OSHPD

Corresponding Member

Bonnie Manley

Steel Market Develop Insitute

Corresponding Member

Dan Sloat

Degenkolb Engineers

Corresponding Member

J. G. (Greg) Soules

CB&I Storage Tank Solutions

Corresponding Member

Taka Tamiya

Degenkolb Engineers

Corresponding Member

Robert Tremblay

Polytechnique

 

 

IT 3, Modal Response Spectrum Analys Considerations

Chair

Anindya Dutta

Simpson Gumpertz & Heger

Voting Member

Kevin Aswegan

Magnusson Klemencic Associates

Voting Member

Robert Hanson

University of Michigan

 

Voting Member

 

Jay Harris

National Institute of Standards and

Technology

Voting Member

James Malley

Degenkolb Engineers

Voting Member

Rafael Sabelli

Walter P. Moore

Corresponding Member

Jason Collins

PCS Structural Solutions

Corresponding Member

Finley Charney

Virginia Tech

Corresponding Member

Rob Tovani

Computers and Structures,

IT 4, Shear Wall Design

Chair

S.K. Ghosh

S. K. Ghosh Associates

Voting Member

Dick Bennett

University of Tennessee

Voting Member

Michel Bruneau

University of Buffalo

Voting Member

Kelly Cobeen

Wiss, Janney, Elstner Associates

Voting Member

Jason Collins

PCS Structural Solutions

Voting Member

David Fields

Magnusson Klemencic Associates

Voting Member

Gino Kurama

University of Notre Dame

Voting Member

Andy Taylor

KPFF Consulting Engineers

Corresponding Member

Kevin Aswegan

Magnusson Klemencic Associates

Corresponding Member

Jeff Berman

University of Washington

Corresponding Member

Daniel Borello

Oregon State University

Corresponding Member

Dan Dolan

Washington State University

Corresponding Member

Anindya Dutta

Simpson Gumpertz & Heger

Corresponding Member

Larry Fahnestock

University of Illinois at Urbana-Champaign

Corresponding Member

Joe Ferzli

Cary Kopczynski & Company

Corresponding Member

John Hooper

Magnusson Klemencic Associates

Corresponding Member

Dawn Lehman

University of Washington

Corresponding Member

Philip Line

American Wood Council

Corresponding Member

Bonnie Manley

American Iron and Steel Institute

Corresponding Member

Joe Maffei

Maffei Structural Engineering

Corresponding Member

Jack Moehle

University of California Berkeley

Corresponding Member

Lawrence Novak

Portland Cement Association

Corresponding Member

Laura Lowes

University of Washington

Corresponding Member

Jose Restrepo

University of California, San Diego

Corresponding Member

Rafael Sabelli

Walter P. Moore

 

Corresponding Member

 

Siamak Sattar

National Institute of Standards and

Technology

Corresponding Member

Amit Varma

Purdue University

Corresponding Member

John Wallace

University of California, Los Angeles

Corresponding Member

Andrew Whittaker

University of Buffalo

Corresponding Member

Tom Xia

DCI Engineers

Corresponding Member

Kirsten Zeydel

ZO Consulting

 

 

IT 5, Nonstructural Components

Chair

John Gillengerten

SE, Retired OSHPD

Voting Member

Peter Carrato

Bechtel Power Corporation

Voting Member

Travis Churpalo

Degenkolb Engineers

Voting Member

William Holmes

Rutherford + Chekene

Voting Member

Bret Lizundia

Rutherford + Chekene

Voting Member

John Silva

Hilti

Voting Member

J. G. (Greg) Soules

CB&I Storage Tank Solutions

Voting Member

Chris Tokas

OSHPD

Corresponding Member

Hussain Bhatia

OSHPD

Corresponding Member

Phil Caldwell

Schneider

Corresponding Member

Meaghan Halligan

ISAT

 

Corresponding Member

 

Matthew Hoehler

National Institute of Standards and

Technology

Corresponding Member

Robert Pekelnicky

Degenkolb Engineers

Corresponding Member

Maryann Phipps

Estructure

Corresponding Member

Robert Simmons

Petra Seismic Design

Corresponding Member

Siavash Soroushian

Arup

IT 6, Nonbuilding Structures

Chair

Peter Carrato

Bechtel Power Corporation

Voting Member

J. G. (Greg) Soules

CB&I Storage Tank Solutions

Voting Member

Bill Scott

AISC Industrial building committee

Voting Member

Eric Wey

Fluor

Corresponding Member

Rick Drake

Fluor

Corresponding Member

John Rolfes

Computerized Structural Design

Corresponding Member

Robert Simmons

Petra Seismic / ASHRAE

Corresponding Member

John Silva

Hilti

Corresponding Member

Harold Sprague

Parsons

IT 7, Soil-Foundation Interaction

Chair

Stephen Harris

Simpson Gumpertz & Heger

Voting Member

C.B. Crouse

AECOM

Voting Member

Gyimah Kasali

Rutherford + Chekene

Voting Member

Ian McFarlane

Magnusson Klemencic Associates

Voting Member

Robert Pekelnicky

Degenkolb Engineers

Voting Member

Jonathan Stewart

University of California, Los Angeles

Corresponding Member

Bruce Kutter

University of California Davis

Corresponding Member

Armin Masroor

Arup

 

 

IT 8, Base Isolation and Energy Dissipation

Deactivated

IT 9, Diaphragm Issues - RWFD and Alternate Provisions for Diaphragm Design

Chair

Kelly Cobeen

Wiss, Janney, Elstner Associates

Voting Member

John Lawson

Cal Poly San Luis Obispo

Voting Member

S.K. Ghosh

S. K. Ghosh Associates

Voting Member

Ron La Plante

California Division of the State Arch

Voting Member

Ben Schafer

Johns Hopkins University

Voting Member

Tom Sabol

Engelkirk & Sabol

Corresponding Member

Pouria Bahmani

KPFF Consulting Engineers

Corresponding Member

Patrick Bodwell

Vulcraft/ Verco Group

Corresponding Member

Dan Dolan

Washington State Universtiy

Corresponding Member

Matt Eatherton

Virginia Tech

Corresponding Member

Andre Filiatrault

SUNY University at Buffalo

Corresponding Member

Christopher Gill

Hilti North America

Corresponding Member

Dave Golden

ASC Steel Deck Div. of ASC Profiles

Corresponding Member

Jerome (Jerry) Hajjar

Northeastern University

Corresponding Member

Steve Hobbs

Vulcraft

Corresponding Member

Maria Koliou

Colorado State University

Corresponding Member

William Holmes

Rutherford + Chekene

Corresponding Member

Philip Line

American Wood Council

Corresponding Member

Bonnie Manley

American Iron and Steel Institute

Corresponding Member

Scott Schiff

Applied Technology Council

Corresponding Member

Walt Schultz

Nucor

Corresponding Member

Andrew Shuck

Wiss, Janney, Elstner Associates

Corresponding Member

Robert Tremblay

Polytechnique Montreal

Corresponding Member

Tom Xia

DCI Engineers

IT 10, Seismic Design Value Maps

Chair

C.B. Crouse

AECOM

Voting Member

Ron Hamburger

Simpson Gumpertz & Heger

Voting Member

Jim Harris

James Harris & Associates

Voting Member

William Holmes

Rutherford + Chekene

Voting Member

John Hooper

Magnusson Klemencic Associates

Voting Member

Charles Kircher

Charles Kircher & Associates

Voting Member

Nicolas Luco

U.S. Geological Survey

Voting Member

Sanaz Razaeian

U.S. Geological Survey

Voting Member

Jonathan Stewart

University of California Los Angeles

 

Project 17 Work Groups

 

WG1, Uncertainty and Precision

Chair

Dan Dolan

Washington State University

Member

Ben Enfield

City of Seattle Building Department

Member

Jon Heintz

Applied Technology Council

Member

Nicolas Luco

U.S. Geological Survey

Member

Robert Pekelnicky

Degenklob Engineers

WG2, Acceptable Risk

Chair

Robert Pekelnicky

Degenkolb Engineers

Member

Ibbi Amufti

ARUP

Member

Jack Baker

Stanford University

Member

C.B. Crouse

AECOM

Member

Jon Heintz

Applied Technology Council

Member

William Holmes

Rutherford + Chekene

Member

John Hooper

Magnusson Klemencic Associates

Member

Charles Kircher

Charles Kircher & Associates

Member

Nicolas Luco

U.S. Geological Survey

Member

Siamak Sattar

National Institute of Standards and Technology

Member

Jonathan Stewart

University of California, Los Angeles

WG3, Multi-Period Spectral Parameters

Chair

Charles Kircher

Charles Kircher & Associates

Member

David Bonneville

Degenkolb Engineers

Member

C.B. Crouse

AECOM

Member

John Hooper

Magnusson Klemencic Associates

Member

Nicolas Luco

U.S. Geological Survey

Member

Sanaz Rezaeian

U.S. Geological Survey

Member

Jonathan Stewart

University of California, Los Angeles

WG4, Deterministic Maps

Chair

C.B. Crouse

AECOM

Member

Ned Field

U.S. Geological Survey

Member

John Hooper

Magnusson Klemencic Associates

Member

Charles Kircher

Charles Kircher & Associates

Member

Nicolas Luco

U.S. Geological Survey

Member

Sanaz Rezaeian

U.S. Geological Survey

Member

Jonathan Stewart

University of California, Los Angeles

WG5, Seismic Design Category

Chair

Julie Furr

Rimkus Consulting Group

Member

Dan Dolan

Washington State University

Member

Jim Harris

James Harris & Associates

Member

William Holmes

Rutherford + Chekene

Member

John Hooper

Magnusson Klemencic Associates

Member

Robert Pekelnicky

Degenkolb Engineers

Member

Jon Siu

City of Seattle, Washington

Member

Paul Timko

Cromwell Architects Engineers

 

 

 

Project 17 Planning and Advisory Committees

 

 

Project 17 Planning Committee Participants

Chair

Ronald Hamburger

Simpson Gumpertz & Heger Inc.

Member

David Bonneville

Degenkolb Engineers

Member

C.B. Crouse

AECOM

Member

Edward Field

U.S. Geological Survey

Member

Arthur Frankel

U.S. Geological Survey

Member

Robert Hanson

University of Michigan (Emeritus)

Member

James Harris

James Harris & Associates

Member

William Holmes

Rutherford & Chekene

Member

John Hooper

Magnusson Klemencic Associates

Member

Charles Kircher

Kircher & Associates

Member

Nicolas Luco

U.S. Geological Survey

Member

Morgan Moschetti

U.S. Geological Survey

Member

Robert Pekelnicky

Degenkolb Engineers

Member

Mark Petersen

U.S. Geological Survey

Member

Peter Powers

U.S. Geological Survey

Member

Sanaz Rezaeian

U.S. Geological Survey

Member

Philip Schneider

Building Seismic Safety Council

Member

Mai Tong

Federal Emergency Management Agency

Project 17 Advisory Committee

Chair

Jennifer Goupil

American Society of Civil Engineers

Member

Philip Caldwell

Schneider Electric

Member

John Egan

Consulting Engineer

Member

Gary Ehrlich

National Association of Home Builders

Member

Kevin Moore

Simpson Gumpertz & Heger

Member

Mike Mota

Concrete Reinforcing Steel Institute

Member

Adrian Rodrigues-Merak

Virgina Tech

Member

J. G. (Greg) Soules

CB&I Storage Tank Solutions

Member

Zia Zafir

Kleinfelder

 

Project Management

 

Project Management

FEMA Project Manager

Mai Tong

Federal Emergency Management Agency

PUC Chair

David Bonneville

Degenkolb Engineers

NIBS Project Manager

Jiqiu (JQ) Yuan

National Institute of Building Sciences

NIBS Project Manager

Philip Schneider1

National Institute of Building Sciences

 

1 Year 2015-2019

BSSC Board of Direction

 

2018-2019 Board of Direction

Chair

James Cagley

Cagley & Associates

Vice Chair

Charlie Carter

American Institute of Steel Construction

Secretary

Jennifer Goupil

American Society of Civil Engineers

At-Large

Bahram Zarin-afsar

Zarin-afsar & Associates

At-Large

Mike Pfeiffer

International Code Council

NIBS Board Liaison

Anne Ellis

Anne Ellis, LLC

2017-2018 Board of Direction

Chair

James Cagley

Cagley & Associates

Vice Chair

Charlie Carter

American Institute of Steel Construction

Secretary

Jennifer Goupil

American Society of Civil Engineers

At-Large

Bahram Zarin-afsar

Zarin-afsar & Associates

NIBS Board Liaison

Anne Ellis

Anne Ellis, LLC

2016-2017 Board of Direction

Chair

Jim Sealy

FAIA, Dallas, TX

Vice Chair

James Cagley

Cagley & Associates

Secretary

Susan Dowty

International Code Council

At-Large

Charlie Carter

American Institute of Steel Construction

At-Large

Jennifer Goupil

American Society of Civil Engineers

NIBS Board Liaison

Anne Ellis

Anne Ellis, LLC

2015-2016 Board of Direction

Chair

Jim Sealy

FAIA, Dallas, TX

Vice Chair

James Cagley

Cagley & Associates

Secretary

Melvyn Green

Melvyn Green & Associates

 

 

 

 

 

Members

Remington Brown

Insurance Institute for Building and Home Safety

Charles Carter

American Institute of Steel Construction

Bradford Douglas

Engineering American Wood

Jennifer Goupil

American Society of Civil Engineers

Perry Haviland

FAIA, Oakland, CA

John Hayes

NIST, NEHRP Director

Jay Larson

American Iron and Steel Institute

Ron Lynn

Clark County Government Center, Las Vegas, NV

Greg Schindler

KPFF Consulting Engineers

Matthew Senecal

American Concrete Institute

Stephen Szoke

Portland Cement Association

Jason Thompson

National Concrete Masonry Association

 

BSSC Member Organizations

 

Organization

Representative

American Concrete Institute

Khaled Nahlawi

American Institute of Architects

Perry Haviland

American Institute of Steel Construction

Larry Kruth

American Iron and Steel Institute

Bonnie Manley

American Society of Civil Engineers

Jennifer Goupil

American Wood Council

Bradford Douglas

The Engineered Wood Association

Thomas Skaggs

Applied Technology Council

Jim Cagley

ASHRAE

Robert Simmons

Builiding Owners and Managers Association

John Catlett

California Department of General Services

Diane Gould

Concrete Masonry Association of California and Nevada

Kurt Siggard

Concrete Reinforcing Steel Institute

Danielle Kleinhans

Concrete Reinforcing Steel Institute

David Fanella

Department of Veterans Affairs

Juan Archilla

General Services Administration

William Earl

Insurance Institute for Business and Home Safety1

Anne Cope

International Code Council

Mike Pfeiffer

Metal Building Manufacturers Association

Lee Shoemaker

National Association of Homebuilders

Gary Ehrlich

National Concrete Masonry Association

Jason Thompson

National Council of Structural Engineers Associations

Kevin Moore

Portland Cement Association

Paul Tennis

Precast/Prestressed Concrete Institute

Roger Becker

Rack Manufacturers Institute

Victor Azzi

Steel Deck Institute

Robert Paul

Structural Engineer Association of Washington

Patrick Lindblom

Structural Engineers Association of California

Don Schinske

Structural Engineers Association of Central California

David Palmer

Structural Engineers Association of Colorado2

Rob Jackson

Structural Engineers Association of Illinois

Jon Sfura

Structural Engineers Association of Kansas & Missouri

F. Alan Wiley

Structural Engineers Association of Northern California

Ken Miles

Structural Engineers Association of Oregon3

Reid Zimmerman

Structural Engineers Association of San Diego

Heather Caya

Structural Engineers Association of Southern California

Dianne Ochoa

Structural Engineers Association of Utah

Philip Miller

Steel Joist Institute

Kenneth Charles

The Masonry Society

Philip Samblanet

Note: 1. membership 2017-2018. 2. membership 2018-2020. 3. membership 2019-2020.


NOTICE: Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of the Federal Emergency Management Agency. Additionally, neither FEMA nor any of its employees make any warranty, expressed or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product, or process included in this publication.

Prepared for the Federal Emergency Management Agency of the U.S. Department of Homeland Security
By the Building Seismic Safety Council of the National Institute of Building Sciences