Study on the Behavior of Power Cables under External Forces in Duct : A Case Study from a EHV Cable System in South Korea

In South Korea, an extra high voltage cable system was installed prior to its commercial operation. Before the system was energized, unexpected cable movement was observed, particularly on sloped sections and industrial roads. Gravity and repeated vehicle loads caused cables to move, eliminating the pre-installed offset in manholes. This offset is essential for absorbing thermal expansion during operation; its loss may increase mechanical stress on joints.