Seismic Design and Assessment of Natural Gas and Liquid Hydrocarbon Pipelines

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

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

2.0

1.5

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

1.6

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

1.7

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

1.8

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

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

3.0

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

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

4.0

3.2

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

3.3

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

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

5.0

4.5

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

4.6

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

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

PR-268-9823