Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
권호 표지
DOI QR코드

DOI QR Code

The Study on the Stress Concentration Ratio of Low Slump Mortar Grouting Mixtures for Improving the Soft Ground

연약지반 보강을 위한 저유동성 몰탈 개량체의 응력분담비에 관한 연구

  • Park, Eonsang (Department of Construction System Engineering, Soongsil Cyber University) ;
  • Kim, Byungil (Institute of Technology, Expert Group for Earth & Environment) ;
  • Park, Seungdo (HanYoung Construction and Technology)
  • Received : 2020.07.13
  • Accepted : 2020.08.27
  • Published : 2020.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, the stress concentration ratio for the improved material of the low slump mortar grouting was evaluated through the composite ground method, the ground arching theory, the plastic angle method, the 2D and 3D numerical analysis and the 3D model experiment. The stress concentration ratio calculated by the composite ground method was 89.3, 3.75~59.0 when the three-dimensional ground arching theory was applied, and 82.8 for the three-dimensional plastic angle method. As a result of the 2D numerical analysis, the stress concentration ratio was 63.0~77.0, which was found to increase as the improvement ratio increased. The results of 3D numerical analysis were predicted to be 50.0~56.0 smaller than the results of 2D analysis. In the case of a special model experiment using a large triaxial compression cell, the stress concentration ratio for each load step was 53.0~60.0, and the stress concentration ratio evaluated by the experiment was measured within 2D and 3D numerical analysis predictions. In this study, a predictive equation for the stress concentration ratio according to the improvement ratio is proposed based on the analysis and experimental values for the improved ratio of the low slump mortar grouting.

본 연구에서는 저유동성 몰탈 주입공법의 개량체에 관한 응력분담비를 복합지반법, 지반아칭이론, 소성각법 및 2차원과 3차원 수치해석, 3차원 모형실험을 통해 평가하였다. 복합지반법으로 계산된 응력분담비는 89.3, 3차원 지반아칭이론을 적용할 경우 3.75~59.0, 3차원 소성각법의 경우 82.8로 이론별 응력분담비의 차이가 나타났다. 2차원 수치해석 결과 응력분담비는 63.0~77.0으로 개량율이 증가할수록 증가하는 것으로 나타났고, 3차원 수치해석 결과 50.0~56.0으로 2차원 해석 결과 대비 작게 예측되었다. 대형 삼축압축셀을 이용한 특수 모형 실험의 경우 하중단계별 응력분담비는 53.0~60.0으로 나타났고, 실험으로 평가한 응력분담비는 2차원과 3차원 수치해석적 예측치 내에서 측정되었다. 본 연구에서는 저유동성 몰탈 주입 공법의 개량체에 대하여 해석 및 실험값을 바탕으로 개량율에 따른 응력분담비에 대한 예측식을 제안하였다.

Keywords

References

  1. BSI (1995), Code of practice for strengthened/reinforced soils and other fills, BS 8006.
  2. Building Center of Japan (2002), Design And Quality Control Guide For Improved Ground For Building, pp. 19-26.
  3. Carlsson, B. (1987), Reinforced soil, principles for calculation, terratema AB, Linkoping, pp. 15-33.
  4. Guido, V. A., Kneuppel, J. D. and Sweeney, M. A. (1987), Plate loading tests on geogrid reinforced earth slabs (New Orleans), Proc. Geosynthetics, pp. 216-225.
  5. Hewlett, W. J. and Randolph, M. F. (1988), Analysis of piled embankments, Ground Engineering, Vol. 21, No. 3, pp. 12-18.
  6. Hong, W. P. and Lee, K. W. (2002), A study on the effect of carrying vertical loads over embankment piles, Journal of The Korean Geotechnical Society, Vol. 18, No. 4, pp. 285-294.
  7. Japan Civil Engineering Research Institute (2007), ALiCC method manual for ground improvement, Kashima publication, pp. 224-229.
  8. Jones, C. J. F. P., Lawson, C. R. and Ayres, D. J. (1990), Geotextile reinforced piled embankments. in: geotextiles, geomembranes and related products, Den Hoedt(ed.), Balkema, Rotterdam, pp. 155-160.
  9. Low, B. K., Tang, S. K. and Chao, V. (1994), Arching in piled embankments, J. of Geo. Eng., ASCE, Vol. 120, No. 11, pp. 1917-1938. https://doi.org/10.1061/(ASCE)0733-9410(1994)120:11(1917)
  10. Shin, H. Y., Kim, B. I., Kim, K. O. and Han, S. J. (2014), A comparative study of structural analysis on DCM improved by pile and block type, Journal of The Korean Geotechnical Society, Vol. 30, No. 4, pp. 5-19. https://doi.org/10.7843/kgs.2014.30.4.5
  11. Spangler, M. G. and Handy, R. L. (1973), Soil engineering (Third Edition), International Textbook Co., pp. 658-696.
  12. Yoo, N. J., Kim, D. G. and Yoon, D. H. (2011), Centrifuge modeling and numerical analysis on breakwater construction, Journal of Industrial Technology, Kangwon Natrional Univ., Korea, No. 31B, pp. 81-90.