Development of Unmanned Deep Foundation Construction Method in Shaft

Deep foundations, because of their economical merits, are frequently used as foundation for steel transmission towers and bridges which are provided in mountain areas, as well as for landslide-restraining pile at scarps. However, the most of the works such as excavation are implemented in a narrow circular vertical shaft by human labor, with extremely severe work environment. Improvement of work environment, enhancement of safety, labor saving, shortening of construction period and cost reduction for deep foundation works by mechanization and automation are of primary concern. To overcome these difficulties, we have successfully developed a comprehensive unmanned construction system which is very innovative in conception and able to cover, from excavation to concrete placing, that is, "unmanned deep foundation construction method in shaft". The paper outlines various technology elements, including the deep foundation excavator, the results of field tests, as well as its applicability to the foundation for steel transmission tower and the expected improvements.