The Dividing Line Standard Research Of Deep Submersed Tunnel And Shallow Submersed Tunnel Of Loess Tunnel

The dividing line question of deep submersed tunnel and shallow submersed tunnel, always is concern about the academe and engineering. The dividing line standard is important to estimate the character of the surrounding rock pressure for tunnel lining. The traditional dividing line standard regarding the great span loess highway tunnel is unsuitable and the concrete analysis should unify the numerical analysis method to carry on.Using numerical simulation analysis, in view of the dividing line to deep submersed tunnel and shallow submersed tunnel, the author has analyzed the factor of burying depth, tunnel diameter, nature of the soil and way of construction.Quad the distinction factor by soil lateral pressure coefficient and ratio of internal to external deformation, the author make some conclusion. Excavation and unloading arose the additional stress on the top of arches center, and the additional stress size has decided deep submersed tunnel and shallow submersed tunnel condition. Regarding the shallow submersed tunnel, soil lateral pressure coefficient will augment after excavation under foot. Regarding the deep submersed tunnel, soil lateral pressure coefficient will keep immovability after excavation under foot. The different burying depth condition tunnel is different of deformation after excavation. Regarding the shallow submersed tunnel, ratio of internal to external deformation is bigger on the top of arches center and changes to beeline. Regarding the deep submersed tunnel, ratio of internal is small on the top of arches center and changes to hyperbola.Using numerical simulation analysis, simulates the process of excavation of three loess tunnels, analyzes the change of the settlement on the earth's surface,the deformation of soil,the stress of soil,the pressure of line and invert, analyzes the estate of deep submersed tunnel and shallow submersed tunnel, checks up the Dividing line method which is studied by the paper. The conclusion indicated that the method which is studied by the paper is fit for the fact, and can consider the influence of more factors.