Catalog No. L51927

Guidelines for the Seismic Design and Assessment of Natural Gas and Liquid Hydrocarbon Pipelines

Contract PR-268-9823

Prepared for the

Pipeline Design, Construction & Operations Technical Committee

of Pipeline Research Council International, Inc.

Prepared by the following Research Agencies:

D.G. Honegger Consulting D.J. Nyman and Associates

Authors: Douglas G. Honegger

Douglas J. Nyman

Publication Date: October 1, 2004

PR-268-9823

GUIDELINES FOR THE SEISMIC DESIGN AND ASSESSMENT OF NATURAL GAS AND

LIQUID HYDROCARBON PIPELINES

PART I

GUIDELINES AND RECOMMENDED PROCEDURES

PR-268-9823

Table of Contents

1.0 GENERAL PROVISIONS .................................................................................. 1-1

1.1 Application ...................................................................................................1-1

1.2 Process ..........................................................................................................1-1

1.3 Alternate Procedures.....................................................................................1-3

1.4 Required Information....................................................................................1-3

1.4.1 Pipe Information..................................................................................1-3

1.4.2 Soil Information ..................................................................................1-4

1.4.3 Seismic Hazard Definition..................................................................1-4

1.5 Acronyms......................................................................................................1-4

1.6 Nomenclature................................................................................................1-5

1.7 References...................................................................................................1-10

1.8 Units............................................................................................................ 1- 11

2.0 QUANTIFYING SEISMIC HAZARDS............................................................. 2-1

2.1 Surface Faulting............................................................................................2-1

2.1.1 Empirical Methods for Estimating Fault Displacements ....................2-2

2.1.2 Orthogonal Displacement Components ..............................................2-3

2.1.3 Design Fault Displacements................................................................2-4

2.2 Peak Ground Acceleration............................................................................2-6

2.2.1 Near Source Earthquakes in the Western United States .....................2-7

2.2.2 Cascadia Earthquakes..........................................................................2-8

2.3 Liquefaction..................................................................................................2-9

2.3.1 Assessing Liquefaction Potential ........................................................2-9

2.3.2 Displacements Associated with Relative Buoyancy.........................2-13

2.3.3 Displacements Related to Liquefaction-Induced Settlement ............2-14

2.4 Lateral Spread Movement...........................................................................2-14

2.5 Landslides ...................................................................................................2-16

2.6 Seismic Wave Propagation.........................................................................2-18

2.7 Transient Ground Deformation...................................................................2-19

3.0 PIPELINE PERFORMANCE CRITERIA........................................................ 3-1

3.1 New Pipelines and Pipelines Compatible with Modern Construction Practices.....................................................................3-2

3.1.1 Performance Goal: Maintain Pressure Integrity.................................3-2

PR-268-9823

3.1.2 Performance Goal: Maintain Normal Operability..............................3-3

3.1.3 Load-Controlled Conditions ................................................................3-4

3.2 Considerations for Offshore Pipelines ..........................................................3-5

3.3 Pipelines Not Compatible with Current Construction Practices...................3-6

4.0 PIPELINE ANALYSIS PROCEDURES ........................................................... 4-1

4.1 Pipe Element Definition ...............................................................................4-1

4.2 Pipe Stress-Strain Definition ........................................................................4-1

4.3 Soil Spring Definition...................................................................................4-2

4.3.1 Axial Soil Springs ...............................................................................4-2

4.3.2 Lateral Soil Springs .............................................................................4-3

4.3.3 Vertical Uplift Soil Springs.................................................................4-4

4.3.4 Vertical Bearing Soil Springs..............................................................4-5

4.4 Extent of Pipeline Model..................................................................................4-5

4.5 Representation of Applied Ground Movement .............................................4-6

4.6 Sensitivity Analyses......................................................................................4-6

5.0 MITIGATION OPTIONS ................................................................................... 5-1

5.1 Modifying Pipeline Loading Conditions ......................................................5-1

5.1.1 Reducing Soil Loads by Minimizing Soil Strength Properties ...........5-1

5.1.2 Unanchored Length.............................................................................5-4

5.1.3 Isolating Pipelines from Ground Displacement ..................................5-4

5.2 Modify Pipeline Configuration.....................................................................5-4

5.3 Modify Emergency Response Procedures ....................................................5-5

APPENDIX A: Considerations for Establishing Performance Goals

APPENDIX B: Seismic Design Provisions in Existing Standards

APPENDIX C: Probabilistic Seismic Hazard Analysis

APPENDIX D: Example Calculations

APPENDIX E: Guideline Reviewers

PR-268-9823

GUIDELINES FOR THE SEISMIC DESIGN AND ASSESSMENT OF NATURAL GAS AND

LIQUID HYDROCARBON PIPELINES

PART II

COMMENTARY

PR-268-9823

Table of Contents

C1.0 GENERAL PROVISIONS ...............................................................................C1-1

C1.1 Application ................................................................................................C1-1

C1.2 Process .......................................................................................................C1-1

C1.3 Alternate Procedures..................................................................................C1-3

C1.4 Required Information.................................................................................C1-3

C2.0 QUANTIFYING SEISMIC HAZARDS..........................................................C2-1

C2.1 Surface Faulting.........................................................................................C2-1

C2.1.1 Empirical Methods for Estimating Fault Displacements ............C2-3

C2.1.2 Orthogonal Displacement Components ......................................C2-4

C2.1.3 Design Fault Displacements........................................................C2-5

C2.2 Peak Ground Acceleration.........................................................................C2-7

C2.3 Liquefaction...............................................................................................C2-8

C2.3.1 Assessing Liquefaction Potential ................................................C2-9

C2.3.2 Displacements Associated with Relative Buoyancy.................C2-10

C2.3.3 Displacements Related to Liquefaction-Induced Settlement ....C2-11

C2.4 Lateral Spread Movement ........................................................................C2-12

C2.5 Landslides ................................................................................................C2-13

C2.6 Seismic Wave Propagation......................................................................C2-16

C2.7 Transient Ground Deformation................................................................C2-18

C3.0 PIPELINE PERFORMANCE CRITERIA.....................................................C3-1

C3.1 New Pipelines and Pipelines Compatible with Current Construction Practices ..................................................................C3-1

C3.1.1 Performance Goal: Maintain Pressure Integrity.........................C3-5

C3.1.2 Performance Goal: Maintain Normal Operability......................C3-8

C3.1.3 Load-Controlled Conditions ........................................................C3-9

C3.2 Considerations for Offshore Pipelines .....................................................C3-10

C3.3 Pipelines Not Compatible with Current Construction Practices..............C3-11

C4.0 PIPELINE ANALYSIS PROCEDURES ........................................................C4-1

C4.1 Pipe Element Definition ............................................................................C4-2

C4.2 Pipe Stress-Strain Definition .....................................................................C4-3

PR-268-9823

C4.3 Soil Spring Definition................................................................................C4-3

C4.4 Extent of Pipeline Model...........................................................................C4-5

C4.5 Representation of Applied Ground Movement ..........................................C4-5

C4.6 Sensitivity Analyses...................................................................................C4-6

C5.0 MITIGATION OPTIONS ................................................................................C5-1

C6.0 REFERENCES ..................................................................................................C6-1