Application of steel frame viaduct for mountainous roads in Vietnam: Case studies in Quang Ngai Province and Lam Dong Province

Vietnam’s mountainous highways are increasingly affected by landslides each year, with climate change being a major cause. The government has allocated significant funds to repair, rehabilitate, and maintain these highways, but conventional methods like excavation and embankment are not always effective for roads that pass through unstable, large-angle slopes that have a high risk of landslides. This results in additional rehabilitation costs following natural disasters. To address this issue, JFE Civil Engineering & Construction Corporation has developed a new solution for constructing mountainous highways in Vietnam - a viaduct that functions as a space steel frame supported by steel pipe columns and beams. Prefabricated in a factory and transported to the construction site, the steel beams are then assembled, and steel piles are driven deep into the ground for a rigid pile-to-ground connection. These proposed structures offer sustainable and cost-effective solutions for mountainous highways with minimal impact on the surrounding environment. Two case studies in Quang Ngai Province and Lam Dong Province are presented as preliminary designs to demonstrate the feasibility of this solution.