Journal of the Korean Geosynthetics Society (한국지반신소재학회논문집)

Korean Geosynthetics Society (한국지반신소재학회)
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A Case Study on the Reinforcement of Existing Damaged Geogrid Reinforced Soil Wall Using Numerical Analyses

수치해석을 이용한 기존 피해 보강토 옹벽의 보강에 관한 사례 연구

  • Received : 2020.03.13
  • Accepted : 2020.03.25
  • Published : 2020.03.30
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Abstract

There have been often cases of collapse for geogrid reinforced soil (GRS) retaining wall. Hence, social interest in the reinforcement and restoration of the collapsed GRS wall is increasing day by day. However, there are only few researches. For this reason, a series of numerical analyses using the Plaxis 2D program was conducted in this study to analyze the suitable reinforcement methods that can be applied on the existing damaged GRS wall caused by overturning of the modular blocks facing and the surface settlement at the backfill as the results from the design failure. The restoration plan used in this study is composed of two cases: (Case 1) soil nailing reinforcement and reinforced concrete (RC) wall facing construction on the existing damaged GRS wall; and (Case 2) removal of the entire damaged GRS wall and then reconstruction. The results on the internal stability of the GRS wall show that Case 1 obtained a greater safety factor than Case 2 for tensile force while Case 2 had a greater safety factor than Case 1 for pullout failures. Case 1 was found to be more stable than Case 2 in terms of the global slope safety by shear strength reduction method and the external deformation behavior by numerical analysis. In this study, the existing damaged GRS wall which was reinforced using Case 1 method shows more stable external behavior.

보강토 옹벽이 붕괴되는 사례가 종종 발생되면서, 붕괴된 옹벽의 보강 및 복구에 대한 사회적인 관심은 날로 커지고 있으나 이에 대한 연구는 미미한 경향이 있다. 이와 같은 배경 아래, 본 연구에서는 Plaxis 2D프로그램을 이용한 일련의 수치해석을 수행하여 설계부실로 전면블록의 전도와 배면 침하 피해가 발생된 기존 보강토 옹벽을 복구할 수 있는 방안에 대한 사례연구를 수행하였다. 복구방안으로는 기존 피해 보강토 옹벽에 쏘일네일링과 보강콘크리트(RC) 전면벽체를 보강하는 방안(Case 1)과 기존 피해 보강토 옹벽을 제거하고 재시공하는 방안(Case 2)으로 검토하였다. 보강토 옹벽의 내적안정검토결과는 파단에 대해서는 Case 1이 Case 2보다 크고 인발에 대해서는 Case 2가 Case 1보다 안전율이 크게 나타났다. 수치해석에 의한 외적거동과 전단강도감소법에 의한 전체사면안정 안전율은 Case 1이 Case 2보다 안정적으로 나타났다. 본 연구에서는 보다 안정적인 외적거동을 나타내는 Case 1로 기존 피해 보강토 옹벽을 보강하도록 하였다.

Keywords

References

  1. Do, J. N., Lee, K. H., Kim, N. Y. and Park, Y. H. (2018), "A case study of damage occurred in reinforced earth retaining wall supporting high embankment slope", Korean Society of Civil Engineers Conference, pp.626-627. (in Korean)
  2. Do, J. N., Nam, M. S., Lee, B. J., Kim, Y. H. and Park, Y. H. (2017), "Stability evaluation of reinforced earth retaining walls due to horizontal and longitudinal behavior", Korean Society of Civil Engineers Conference, pp.39-40. (in Korean)
  3. Han, J. G., Cho, S. D., Jeong, S. S, Lee, K. W. and Kim, J. S. (2005), "Case study on the countermeasure methods and collapsed sources of segmental retaining wall considering site conditions", Journal of Korean Geosynthetics Society, Vol.4, No.3, pp.35-43. (in Korean with English abstract)
  4. Hong, G. G., You, S. K., Yun, J. M., Park, J. B., and Lee, K. W. (2016), "A case study on collapses and restoration of retaining wall with vegetated concrete block", Journal of Korea Geosynthetics Society, Vol.15, No.4, pp.105-115. (in Korean with English abstract) https://doi.org/10.12814/jkgss.2016.15.4.105
  5. Hong, K. K., Han, J. G., Lee, K. W. and Park, J. B. (2014), "A case study on reinforcement and design application of reinforced earth wall using micro pile", Journal of Korean Geosynthetics Society, Vol.13, No.4, pp.161-167. (in Korean with English abstract) https://doi.org/10.12814/jkgss.2014.13.4.161
  6. Kim, T. S., Kim, H. J., Nam, M. S. and Jung, J. H. (2013), "Case study of reinforced earth retaining wall; it's collapse and repair", Korean Society of Civil Engineers Conference, pp.2595-2598. (in Korean)
  7. Lee, J. H., Oh, D. W., Kong, S. M., Jung, H. S. and Lee, Y. J. (2018), "Investigation of behaviour of wall and adjacent ground considering shape of geosynthetic retaining wall", Journal of Korean Geosynthetics Society, Vol.17. No.1, pp.95-109. (in Korean with English abstract) https://doi.org/10.12814/JKGSS.2018.17.1.095
  8. Won, M. S., Choi, J. H., Kim, Y. S. and Kim, C. W. (2012), "Collapsed Geosynthetics Reinforced Segmental Retaining Wall Restoration using Unit Soil Nailing", KGS Spring National Conference, pp.283-288. (in Korean with English summary)
  9. Won, M. S., Kim, H. J., Kim, Y. S. and Choi, J. H. (2013), "A case study on the restoration of collapsed geosynthetics reinforced soil wall using limit equilibrium and numerical analyses", Journal of the Korean Geotechnical Society, Vol.29, No.11, pp.107-118. (in Korean with English abstract) https://doi.org/10.7843/kgs.2013.29.11.107
  10. You, C. K. and Jung, H. S. (2006), "Rainfall and performance of soil-reinforced retaining wall - investigation on case histories", Journal of Korean Geosynthetics Society, Vol.5, No.3, pp.17-24. (in Korean with English abstract)