기존터널 상부 근접시공으로 인한 영향 및 대책

If the inevitable large-scale cut sections adjacent to the upper rail-way tunnel have to be constructed, existing tunnel occurs to the upward displacement because of decrease the load in the ground due to the decrease of soil depth. And it is damaged the arching effect in the surrounding ground. As a result of this, pressure to act on the tunnel linings is increased. To secure the stability of the tunnel, reinforcement of the lower structure and surrounding ground is necessary. However, criteria related to the reinforcing zone are not established. In this paper, it evaluated the safety zone through the numerical analysis in case of large-scale cut sections construction adjacent to the upper rail-way tunnel. It has suggested to the reinforcement method that is able to exclude the mutual interference about reinforcing necessary zone.