Abstract: The excavation method of shallow buried tunnels in the mountain area is an important topic in the civil engineering construction. An improved tunnel excavation that reserving the core area by using Cross Diaphragm (CRD) method was applied in the Baishiguan Tunnel excavation. The main construction aspects of this new method are discussed from the construction principles and key construction steps. The key points of the site construction management are discussed from five aspects: advanced support by using the small diameter pilot pipe, excavation and support, inverted arch filling, temporary support removal, and prediction information feedback. The engineering results show that the improved CRD method has the advantages of optimizing the construction technology, information construction, saving construction schedule and investment. The relevant results can be used as reference for actual engineering project. 

Key words: Construction Technology, Tunnel Project, Improved Cross Diaphragm Method, Excavation Technology