The buried or below-grade sections of electric utility steel transmission and distribution structures are often subject to corrosive environments and are not easily accessible for visual inspection. Prior to the publication of this standard, no industry practice existed to help electric utilities determine a prioritized listing of structures to be inspected or that described an inspection and assessment procedure to evaluate below-grade corrosion problems.
High voltage direct current (HVDC) transmission results in a large direct current will into the earth. This may cause interference on a buried pipeline even though it is far from the earth electrode. In this work, numerical simulation was used to study the mechanism and influencing factors of HVDC interference.