Analysis of the Limitations of the Splicing Coordinate System of Subsections in Mountain-Crossing Roads
In mountain-crossing road projects in mountainous areas,there is a significant difference in the side length of control points between the splicing coordinate system of segment projection and the independent coordi-nate system of tunnels at both ends of the tunnel.According to the length deformation of naturalizing the side length of the ground to the reference ellipsoid,this study analyzes the overall deformation of the splicing coordinate system on the mountain-cross road,and compared with the independent coordinate system of tunnels with the av-erage elevation of tunnel projects as the compensating projection surface,obtains the inconsistency between the splicing coordinate system of subsections and the independent coordinate system of tunnels.Through engineering examples,this study summarizes the limitations of the side length deformation of the splicing coordinate system of subsections when mountain roads encounter tunnel projects,as well as the precautions of applying the splicing coor-dinate system and its impact on tunnel holing-through.