A numerical study on the 3-Dimensional shape characteristics of small underground cavities

소규모 지하공동 3차원 형상 특성을 반영한 수치해석에 관한 연구

  • 안준상 ((주)베이시스소프트 건설IT연구소) ;
  • 강경남 (인하대학교 토목공학과) ;
  • 송기일 (인하대학교 토목공학과) ;
  • 김우석 (한국건설기술연구원 인프라안전연구본부) ;
  • 김병찬 ((주)베이시스소프트 건설IT연구소)
  • Received : 2018.06.20
  • Accepted : 2018.07.31
  • Published : 2018.09.30


When conducting the underground safety impact assessment under the special law in Korea, it is essential to investigate the occurrence of underground cavities. When underground cavities were discovered, the underground safety was assessed through numerical analysis. The previous study has suggested the stability evaluation based on the factor of safety by changing the 2D shape of the small underground cavity. In this study, the effects of small underground cavities considering 3D shapes were examined using a continuum analysis program and compared with the 2D results presented in previous study. If the 3-Dimensional shape of the underground cavity is found close to the sphere type, it would be reasonable to evaluate the factor of safety by the shear strength reduction method regardless of the size and position of the cavity. If a high-aspect ratio underground cavity with a depth of 2 m or more from the ground surface and an aspect ratio (a/b) of 2.0 or more is in the vertical direction, not only the factor of safety but the failure mode shape should be cautions in the stability evaluation using the shear strength reduction method. The results of this study are expected to be basic data on underground safety impact assessment.


Grant : 지반함몰 발생 및 피해저감을 위한 지반 안정성 평가 및 굴착.보강기술 개발

Supported by : 국토교통과학기술진흥원


  1. An, J.S., Kang, K.N., Song, K.I., Kim, B.C. (2018), "A numerical study on the characteristics of small underground cavities in the surrounding old water supply and sewer pipeline", Journal of Korean Tunnelling and Underground Space Association, Vol. 20, No. 2, pp. 287-303.
  2. Arellano, D., Stark, T.D. (2000), "Importance of three-dimensional slope stability analyses in practice", In Slope Stability 2000, pp. 18-32.
  3. Bergado, D.T., Teerawattanasuk, C. (2008), "2D and 3D numerical simulations of reinforced embankments on soft ground", Geotextiles and Geomembranes, Vol. 26, No. 1, pp. 39-55.
  4. Choi, S.K., Back, S.H., An, J.B., Kwon, T.H. (2016), "Geotechnical investigation on causes and mitigation of ground subsidence during underground structure construction", Journal of Korean Tunnelling and Underground Space Association, Vol. 18, No. 2, pp. 143-154.
  5. Dhawan, K.R., Singh, D.N., Gupta, I.D. (2002), "2D and 3D finite element analysis of underground openings in an inhomogeneous rock mass", International Journal of Rock Mechanics and Mining Sciences, Vol. 39, No. 2, pp. 217-227.
  6. Drumm, E.C., Akturk, O., Akgun, H., Tutluoglu, L. (2009), "Stability charts for the collapse of residual soil in karst", Journal of Geotechnical and Geoenvironmental Engineering, Vol. 135, No. 7, pp. 925-931.
  7. Hoek, E., Brown, E.T. (1980), "Underground excavations in rock", (No. Monograph).
  8. Hungr, O., Salgado, F.M., Byrne, P.M. (1989), "Evaluation of a three-dimensional method of slope stability analysis", Canadian Geotechnical Journal, Vol. 26, No. 4, pp. 679-686.
  9. Itasca Consulting Group, Inc. (2012), FLAC3D-Fast Lagrangian Analysis of Continua in 3 Dimensions, Version 5.0, User Manual, Minnesota, USA.
  10. Kim, J.B., You, S.K., Han, J.K., Kim, Y.H. (2017), "Experimental study on generating mechanism of the ground subsidence of due to damaged waters supply pipe", Proceedings of the 2017 Spring Geosynthetics Conference, pp. 46-47.
  11. Kim, J.K. (2014), Study on stress state and support for limestone mines excavated room & pillar method, Ph.D. Thesis, Department of Energy and Resources Engineering, Graduate School, Chonnam National University, pp. 15-19.
  12. Kim, S.J. (2013), Stability analysis of the inclined pillars by statistical analysis, Master's Thesis, Department of Energy and Resources Engineering, Graduate School, Chonnam National University, pp. 20-22.
  13. Lee, D.Y., Cho, N.K. (2016), "DEM modelling of underground cavity due to sewer pipe leakage", Proceedings of the 2016 Fall Geosynthetics Conference, pp. 103-104.
  14. Lee, J.H., Jin, H.S., Baek, Y., Yoon, H.S. (2017), "Evaluation of land subsidence risk depending on grain size and verification using numerical analysis", The Journal of Engineering Geology, Vol. 27, No. 2, pp. 133-141.
  15. Lee, J.H., Lee, Y.J. (2014), "Analysis of ground behavior for model tunnel excavation with pipe roof reinforcement using close range photogrammetric technique", Journal of Korean Tunnelling and Underground Space Association, Vol. 16, No. 4, pp. 387-402.
  16. Lee, S.H. (2017), The life cycle informatization and structural stability analysis for double-deck tunnel, Master's Thesis, Department of Civil Engineering, Graduate School, Inha University, pp. 37-52.
  17. Rujikiatkamjorn, C., Indraratna, B., Chu, J. (2008), "2D and 3D numerical modeling of combined surcharge and vacuum preloading with vertical drains", International Journal of Geomechanics, Vol. 8, No. 2, pp. 144-156.
  18. Seoul Metropolitan Government (2014), Announcement of special management measures for road subsidence in Seoul,
  19. Song, W.K., Chung, S.K., Han, K.C. (2002), "Stability analysis of a tunnel above mined cavities", Journal of Korean Tunnelling and Underground Space Association, Vol. 4, No. 2, pp. 135-141.
  20. Park, J.Y., Son, J.H., Park, K.L., Oh, Y.S. (2012), "A study on damage mechanism of transition section in cut and cover tunnel using 3 dimensional numerical analysis", Journal of Korean Tunnelling and Underground Space Association, Vol. 14, No. 6, pp. 653-666.
  21. Park, Y.J., You, K.H. (1998), "Stability analysis for jointed rock slope using ubiquitous joint model", Tunnel & Underground, Journal of Korean Society for Rock Mechanics, Vol. 8, No. 4, pp. 287-295.
  22. You, K.H., Park, Y.J., Kang, Y. (2001), "A numerical study on the estimation of safety factor of tunnels excavated in jointed rock mass", Tunnel and Underground Space, Vol. 11, No. 3, pp. 279-288.