Abstract:
Xianglushan tunnel, a control project of the Water Diversion Project in central Yunnan Province, with a total length of 62.596 km, has the characteristics of ultra-long distance, large section and large buried depth, which is a long-distance deep buried water transmission line with no construction precedent in strong crust activity areas.It faces great construction difficulty.According to the topography, geological conditions and layout conditions of construction branches, the overall construction scheme of TBM and drill-blasting method was determined after multiple schemes comparison.The scheme included setting up construction branches at the tunnel entrance, exit and the main bad geological section, excavating three regional fractures and some bad geological tunnel sections by drill-blasting method and excavating the remaining sections in good geological condition or without construction branches by TBM method.With the goal of optimal construction period, the section length of drill-blasting method and TBM method were analyzed and determined, and the TBM assembly, transfer field and disassembly scheme was formulated.Relevant experience can be used for similar projects.