Research on the breakeven point of human transportation distance in mechanized construction of 110kV overhead transmission lines

Mechanized construction is an important part of the three-year work plan of State Grid Corporation of China's "Six Refinements and Four Modernizations", and mechanized construction of overhead transmission lines in mountainous areas is a major challenge. The breakeven point of human transportation distance is an important indicator for selecting tower locations for mechanized construction in mountainous areas. This paper is based on a survey of the foundation types of mechanized construction in mountainous areas, discussed the cost calculation differences between mechanized construction of overhead transmission lines and conventional construction and analysis the breakeven point for typical terrain conditions of 110kV transmission line, the results show that:(1)The increase in mechanized construction costs is mainly reflected in road construction, environmental and water conservation costs, mechanical earthwork excavation costs, as well as road compensation and deforestation costs. The reduction in mechanized construction costs is mainly reflected in the cancellation of labor transportation costs and the reduction in engineering quantity costs. (2) the breakeven points are between 0-49m on 110kV transmission line.(3) The breakeven point of rock anchor foundation is greater than that of mechanized pile foundations on same condition, indicating that the economic benefits of rock anchor foundations are relatively high.