(A) Study on Stability Analysis of Shallow Tunnel Using Artificial ground at Inclined Area

다국어 초록 (Multilingual Abstract)

In particular, it is mostly the fact that there are many construction mountainous tunnel, because South Korea is formed in the mountainous areas of 65%. In general, construction of mountain tunnel can not be unevitable in excavation of portal, shallow depth and unsymmetrical area. Conversely, From the point of view in geotechnical engineering, there is a high possibility of landslides and tunnel collapse by change of ground surface and excavation in shallow depth. Moreover, collapse type of tunnel portal and tunnel valley, according to ground characteristic, has a great potential to become as ground collapse because tunnel collapse impact is effecting to the ground.
In this study, therefore, the tunnel was analyzed by numerical analysis as countermeasure applied to artificial ground at shallow depth using FLAC-2D ver.7.0. Moreover, it was assessed for stability of tunnel when constructing the tunnel at shallow depth.
It was performed by numerical analysis which applies conditions to capable of comparison and review by changing parameters as factors influencing the ground behaviour such as depth, coefficient of lateral pressure, material and size of artificial ground, when constructing a tunnel at shallow tunnel.
In conclusion, it can be deducted by performing numerical analysis with the suitable size of artificial ground according to type of concrete thickness for selecting a size of artificial ground. Based on numerical analysis of shallow tunnel, in the shallow depth, the change of stability by parameters which include maximum combined stress of shotcrete, convergence displacement at the point of inside of the tunnel as well as crown and ground displacement was reviewed separately.
It was constant for the displacement of tunnel at shallow depth. the more ground condition has, the more deeper depth is. Also, the change of the displacement and stress at the tunnel was presented by increasing the inclination of ground that is upper part of tunnel.
Consequently, it could be obtained for trends about the decrease of displacement and stress by installing a artificial ground at shallow depth.