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The background of this paper is based on Deli tunnel of Xi’an to Chengdu Railway passenger dedicated line. In order to compare and optimize this large section tunnel project under different construction methods, General FEA software ANSYS was utilized to simulate and analyze the stress and deformation in 2-D and 3-D. According to the Deli tunnel engineering case, the preliminary comparison and discussion of mechanical properties and deformation characteristics of the construction of bench cut method and two side-wall pilot tunnel method have been carried out. From this simulation, we made the conclusion for different mechanical properties and deformation characteristics in different construction methods. It shows that the two side-wall pilot tunnel method results in less stress and deformation than the bench cut method. Therefore, it is safer to use the former method. The key step for bench cut method is the upper excavation, and the key step for two side-wall pilot tunnel method is the upper core soil excavation. Monitoring and enhanced support of these key areas is imperative to guarantee the smooth construction.

Abstract:A new type of prefabricated arch culvert is consisted of precast arch pieces and cast-in-place concrete bases. The shape of precast arch pieces is confirmed by catenary theory. In the case of simulating placement in layers of embankment, internal forces of arch piece structure are statically analyzed by using finite element method. The results indicate that under the designed filling height, arch pieces mainly suffer from stress and only very little bending moment and shear force acted on them. The prefabricated arch culverts have reasonable structure stress and simple installation process, which can substantially save materials and shorten project duration of culverts with obvious economic benefits, and should be promoted and applied in mine highway engineering.