The vulnerability of a lifeline to earthquakes is related to the type of structure and to the specific earthquake hazard. Lifeline building structures are vulnerable to earthquake shaking, just as is any building structure. There are many special types of structures found in lifeline systems that have failure modes not commonly found elsewhere. Pipelines constructed of brittle materials are the most vulnerable.
Asbestos cement found in many water systems is also brittle.
Pipelines constructed of ductile materials such as steel and ductile iron are more resistant to earthquake ground motion. If liquefaction occurs, joint restraint is also important. Pipelines buried in liquefiable soils can have failure rates an order of magnitude larger than those in stable soils. Natural gas and liquid fuel pipelines constructed of steel with welded joints have performed well except in the most extreme conditions. Pipeline joints welded with older techniques are in some cases more brittle, and have failed.