Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
권호 표지
DOI QR코드

DOI QR Code

Behavior of braced wall due to distance between tunnel and wall in excavation of braced wall nearby tunnel

터널에 인접한 흙막이굴착 시 터널 이격거리에 따른 거동특성

  • Ahn, Sung Joo (Hwado-Yangpyeong Expressway Section 3, Infra Structure Business Unit, Samsung C&T Corporation) ;
  • Lee, Sang Duk (Dept. of Civil and Transportation Engineering, Ajou University)
  • 안성주 (삼성물산 건설부문 인프라사업부 화도양평간 도로3공구) ;
  • 이상덕 (아주대학교 건설교통시스템공학과)
  • Received : 2018.05.04
  • Accepted : 2018.05.28
  • Published : 2018.07.31
Download PDF
⟨ Previous Next ⟩

Abstract

In recent years, the development of complex urban areas has become saturated and much attention has been focused on the development of underground space, and deep excavation is frequently performed in order to increase the utilization of underground space due to the enlargement of buildings and the high rise of buildings. Therefore, in this study, we tried to understand the behavior of the braced wall and the behavior of the tunnel adjacent to the wall according to the stiffness of the wall and the distance between the tunnel and wall. As a result of the study, the deformation of the braced wall tended to decrease with increasing the stiffness of the wall, and the axial force acting on the struts was also different according to the stiffness of braced wall. When the stiffness of the braced wall is small (2 mm), the point at which the axial force of the braces maximizes is near 0.3H of the wall. When the stiffness of the braced wall is large (5 mm), the axial force is maximum at around 0.7H of the wall. Also, the tunnel convergence occurred more clearly when the separation distance from the braced wall was closer, the stiffness of the wall was smaller, and the tunnel convergence was concentrated to the lower right part. The ground settlement due to the excavation of the ground tended to decrease as the distance between tunnel and braced wall was closer to that of the tunnel, which is considered to be influenced by the stiffness of the tunnel.

최근 복잡한 도심지 개발이 포화상태에 이르러 지하공간 개발에 많은 관심이 집중되고 있으며, 건물의 대형화 및 고층화로 지하공간의 활용도를 높이기 위해 대심도 굴착이 자주 발생하고 있다. 또한, 도심지 기존도로 하부로 지하철, 경전철 등이 건설되고 있어 대형건물 신축을 위한 흙막이 굴착 시 기존 지하구조물과 인접하여 주의를 요하는 사례가 자주 발생하고 있다. 따라서 본 연구에서는 모형시험을 통해 흙막이벽체 강성과 터널 이격거리에 따른 흙막이벽체의 거동특성 및 인접한 터널의 거동을 파악하고자 하였다. 연구 결과, 흙막이벽의 변형은 벽체의 강성이 증가함에 따라 감소하는 경향을 보였으며, 버팀대에 작용하는 축력도 벽체의 강성에 따라 다른 양상을 보였다. 흙막이벽체의 강성이 작은 경우(2 mm) 버팀대 축력이 최대가 되는 지점은 벽체의 0.3H 부근에서 나타났고, 흙막이벽체의 강성이 큰 경우(5 mm)에는 벽체의 0.7H 부근에서 버팀대 축력이 최대로 나타났다. 또한, 터널 내공변위는 흙막이벽체와의 이격거리가 가까울수록, 벽체의 강성이 작을수록 뚜렷하게 발생하였으며 내공변위가 우측하부로 집중되는 경향을 보였다. 지반굴착에 따른 지표침하량은 터널과 흙막이벽체의 이격거리가 가까울수록 지표침하 영향범위가 감소하는 경향을 보였으며 이는 터널의 강성이 영향을 미친것으로 판단된다.

Keywords

References

  1. Back, S.H. (2002), A behavior of braced wall and adjacent ground with the preloading and wall stiffness, Master Thesis, Ajou University, pp. 31-33.
  2. Choi, Y.J. (2013a), "A study on the behavior of the adjacent tunnel due to the deformation of bracing", Proceedings of the KTA 2013 Fall Symposium, November 01, 2013, pp. 67-70.
  3. Choi, Y.J. (2013b), Behavior of a tunnel adjacent to the cut-off wall due to the deformation of bracing, Master Thesis, Ajou University, pp. 1-5.
  4. Duddeck, H., Erdmann, J. (1985), "Structural design models for tunnels in soft soil", Underground Space, Vol. 9, Pergamon Press, pp. 246-259.
  5. Kim, I., Lee, S.D. (2007), "Behavior of tunnel under the influence of pre-loading on braced wall during the adjacent ground excavation", Journal of Korean Tunnelling and Underground Space Association, Vol. 9, No. 4, pp. 331-341.
  6. Lee, J.M. (2010), "Behavior of building lower part passage tunnel due to adjacent ground excavation", Journal of Korean Tunnel and Underground Space Association, Vol. 20, No. 5, pp. 369-377.
  7. Yoo, C.S., Kim, Y.J. (2000), "Behavior of propped walls during deep excavation", Journal of Korea Society of Civil Engineers, Vol. 20, No. 3C, pp. 195-195.