Key issues should be considered for application of strain-based designed pipeline in China

In China, geological conditions along pipelines are very complicated and pipelines may experience large displacement-controlled load in certain areas. In order to design the pipelines with adequate strain capacity, strain-based design method should be introduced. In this paper, some key issues to raise the strain capacity of pipelines were discussed. For material selection, the material properties such as Y/T ratio, uniform elongation, and strain hardening exponent should be set as stated performance index. For pipeline design, measures that enable pipeline to deform with certain flexibility should be taken. For pipeline construction, appropriate weld metal and welding process should be used to guarantee overmatching as well as adequate strength and toughness of welded joints.