Research purposes: The tunnels of Zhengzhou-Xi'an passenger dedicated railway line pass mostly through loess area with the maximum excavation area of 163 m2. In order to guarantee the quality of design, SSDI fully assimilated the valuable consulting comments and unconventional designing ideas from German DEC Company. On the premise of controlling the whole design, the detail designs for side and front slope at portal, reinforcement arrangement for lining of Class II and III surrounding rock, waterproofing and drainage, local reinforcement arrangement of lining are carried out.
Research methods: ANSYS is used for analysis of the finite element internal force of local lining and Sweden slice method, Bishop method, JanBu method and the transmitting coefficients method are adopted for calculating the slope stability. Deliberate the design ideal of the EPC model that is how to have the factor of structure safety and normal service during the construction and operation period to be reflected in the design document.
Research results: By calculating the internal force of local lining, this paper determines the reinforcement arrangement method of the local lining at the corner of sidewall and invert in the open cut tunnel, and nearby the base for drop tube for OCS. By analyzing and comparing for the permanent and temporary side slope of the high side slope of tunnel, this paper determines the design principle of side slope. By comparing for 3 reinforcement arrangement proposals for lining in class II and III surrounding rock adopt the single layer reinforcement arrangement, this paper determines the design proposal of maintainable drainage system and waterproofing layer in open cut tunnel.
Research Conclusions: The reinforcement arrangement for lining should consider transmission for bending moment requirement of equipment fixed in the tunnel, the connection of intercross section between main tunnel and service gallery. The loess property, set-up the height and width of platform have a greater influence on side slope stability. The design of waterproofing and drainage system should consider construction process and maintainability. The detail and outreach design ensure the rationalization, the feasibility and safety of tunnel engineering efficiently.
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