ABSTRACT
This paper is a case study on the design procedure and of the application reinforcement method of tunnel crossing section, which includes two very close high-speed railroad tunnel. In the section 1-1 of the Korea High Speed Railroad Project, the research tunnel of this paper is the Kwang Myung (GM) tunnel intersection with inbound tunnel that leads into Marshaling yard. Minimum distance is about 4.8 m (0.33 D) and crossangle is 37.5 degrees between upper inbound tunnel and lower GM tunnel. This study suggests the estimation procedure of dynamic stability when the dynamic load from train operation is applied. In the dynamic analysis combined reinforcement effect of the mechanical properties of grouted ground and the installed steel pipe is calculated based on the proposed equation. 2-dimensional finite element method is used in the dynamic stability analysis. The results of this study indicate that the vibration is one of the main design parameters for the stability analysis of two closely located tunnels. The results show that the amplitude of propagated stress level is affected significantly depend on the relative distance between two tunnels, but on the other hand the coefficient of lateral earth pressure and reinforcement with large-diameter pipe roof are insignificantly affected to the amplitude of propagated stress level.
