TABLE OF CONTENTS Oil and gas pipeline routes often pass through large geographical areas, from the supply point to the end-user, crossing seismic-active areas. Earthquake damage to oil and gas pipelines can cause significant financial loss, including secondary losses resulting in service interruption, fires, explosions, and environmental contamination. Examples of such catastrophes include the 1964 Alaska Earthquake; the San Fernando Earthquake of 1971; the Guatemala Earthquake in 1976; the 1987 Ecuador Earthquake; the Kobe Earthquake in 1995 and the 2003 Algeria Earthquake. A general conclusion drawn from a review of many earthquake events shows that, for buried steel pipelines, the direct effect of seismic ground wave on the integrity of long and straight pipelines is generally not significant. Where there is permanent ground deformation due to soil failure, there may be a severe influence upon pipeline integrity. For unburied pipelines, both seismic ground wave and permanent ground deformation can cause severe damage to pipelines, depending on the pipeline geometry and connected structures.
Damage to pipeline systems during an earthquake, whether onshore or offshore, can arise from the traveling ground waves and permanent ground deformation due to soil failures. The primary soil failures are:
Faulting;
Landslides;
Liquefaction;
Differential Settlement;
Ground-cracks.
Seismic ground waves produce strains in buried pipelines. However, because there are little or no inertia effects from dynamic excitation, the strains tend to be small and often are well within the yield rupture threshold of the pipeline material. The direct effect of seismic waves is, therefore, generally not expected to cause...
