Abstract
Recently, road tunnel construction using the shield tunneling method has been utilized on infrastructure projects in urban areas. Due to the strict site constraints in urban area, the divergent junctions are to be located underground. Normally, for the construction of an underground diversion junction, large-scale cut and cover methods or the NATM method with ground improvement works shall be adopted. However, these methods involve significant issues relating to safety, cost and the construction period.
We then considered that we could construct a divergent junction with minimum section by cutting through the existing tunnel shield using another shield machine. For the development of a new construction method, various experiments have been carried out using specially designed segments for ease of cutting. This paper discusses the possibility of actually adopting this method based on the experiments undertaken.
