Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Effect of Overburden Stress on Bulb Shapes of Horizontal Compaction Grout in Loose Sand: 2D-scaled Experimental Study

상부 응력이 수평 압밀 그라우팅 구근 형상에 미치는 영향: 2차원 축소 모형 실험 연구

  • Joo, Hyun-Woo (Dept. of Civil and Environmental Engrg., Korea Advanced Institute of Science and Technology) ;
  • Baek, Seung-Hun (Dept. of Civil and Environmental Engrg., Korea Advanced Institute of Science and Technology) ;
  • Kwon, Tae-Hyuk (Dept. of Civil and Environmental Engrg., KAIST) ;
  • Han, Jin-Tae (Dept. of Intrastructure Safety Research, Korea Institute of Civil Engrg. and Building Technology) ;
  • Lee, Ju-Hyung (Dept. of Intrastructure Safety Research, Korea Institute of Civil Engrg. and Building Technology) ;
  • Yoo, Wan-Kyu (Dept. of Intrastructure Safety Research, Korea Institute of Civil Engrg. and Building Technology)
  • 주현우 (한국과학기술원 건설및환경공학과) ;
  • 백승훈 (한국과학기술원 건설및환경공학과) ;
  • 권태혁 (한국과학기술원 건설및환경공학과) ;
  • 한진태 (한국건설기술연구원 인프라안전연구본부) ;
  • 이주형 (한국건설기술연구원 인프라안전연구본부) ;
  • 유완규 (한국건설기술연구원 인프라안전연구본부)
  • Received : 2020.12.10
  • Accepted : 2020.12.18
  • Published : 2020.12.31
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Abstract

The compaction grouting technique is widely used to improve the liquefaction resistance of loose sands that are liquefaction-prone. Particularly, the horizontal injection of compaction grout is proposed for the liquefiable ground with an overlying structure as it does not allow the vertical compaction grouting. However, there has been limited number of researches on the horizontal compaction grouting. Therefore, this study explores the grout bulb shape and expansion direction in loose sand. A series of scaled two-dimensional experiments on the horizontal compaction grouting was conducted varying the overburden stress. The results show that the grout bulb grows in an elliptical shape though its directivity of major axis changes with the overburden effective stress and relative density. The grout bulb expands faster in a horizontal direction under a low overburden stress with a small relative density. The higher overburden stress and the greater relative density cause the more circular shape with the faster expansion in a vertical direction. The presented finding is expected to contribute to accurate and efficient design of the horizontal compaction grouting method.

압밀 그라우팅 공법은 액상화 취약 느슨한 사질토 지반의 보강에 널리 사용되고 있다. 특히 기존에 상부 구조물이 있는 지반의 경우, 압밀 그라우팅 수직 주입이 불가능하여, 수평 주입이 대안으로 제시되고 있는 상황이다. 현재 대부분 이론과 실험은 압밀 그라우팅의 수직 주입 공법을 다루고 있는 반면, 수평 압밀 그라우팅 공법에 대한 연구는 매우 부족하다. 본 연구에서는 수평 압밀 그라우팅 공법에 대한 실내 2차원 실험을 통해 상부 구조물이나 주입 심도를 대변하는 상부 응력에 따른 그라우트 구근 형상과 팽창 방향을 분석하였다. 그 결과 그라우트 구근의 단면은 응력 이방성과 느슨함의 정도에 따라 주로 타원형으로 팽창함을 발견하였다. 특히, 낮은 상부 응력과 낮은 상대 밀도의 조건에 수평축이 긴 타원형으로 수평 방향으로 발달하였고, 상부 응력과 상대 밀도가 증가함에 따라 그 형상이 원형에 가까워지고 수직 방향으로 팽창하였다. 본 연구를 통해 수평 압밀 그라우팅 공법의 구근 팽창에 대한 이해가 높아지고 나아가 보다 정확하고 효율적인 현장 시공 설계가 가능할 것으로 기대된다.

Keywords

References

  1. Cascante, G. and Santamarina, J. C. (1996), Interparticle Contact behavior and Wave Propagation, Journal of geotechnical engineering, Vol.122, No.10, pp.831-839. https://doi.org/10.1061/(ASCE)0733-9410(1996)122:10(831)
  2. De Pater, C. J., Cleary, M. P., Quinn, T. S., Barr, D. T., Johnson, D. E., and Weijers, L. (1994), "Experimental Verification of Dimensional Analysis for Hydraulic Fracturing", SPE Production & Facilities, Vol.9, No.4, pp.230-238. https://doi.org/10.2118/24994-PA
  3. El-Kelesh, A. M., Mossaad, M. E., and Basha, I. M. (2001), "Model of Compaction Grouting", Journal of geotechnical and geoenvironmental engineering, Vol.127, No.11, pp.955-964. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:11(955)
  4. El-Kelesh, A. M., Matsui, T., and Tokida, K. I. (2012), Field Investigation into Effectiveness of Compaction Grouting, Journal of geotechnical and geoenvironmental engineering, Vol.138, No.4, pp.451-460. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000540
  5. Graf, E. D. (1969), "Compaction Grouting Technique and Observations", Journal of the Soil Mechanics and Foundations Division, Vol.95, No.5, pp.1151-1158. https://doi.org/10.1061/JSFEAQ.0001321
  6. Kirsch, K. and Bell, A. (3rd Eds.) (2012), "Ground Improvement", CRC Press.
  7. Meyerhof, G. G. (1957), "Discussion on Research on Determining the Density of Sand by Spoon Testing", In Proc. of 4th ICSMFE (p. 110).
  8. Nam, H., Lee, W., Lee, C., and Choo, H. (2018), Estimation of Unconfined Compressive Strength (UCS) of Microfine Cement Grouted Sand, Journal of the Korean Geotechnical Society, Vol.34, No.7, pp.5-15. https://doi.org/10.7843/KGS.2018.34.7.5
  9. Nichols, S. C. and Goodings, D. J. (2000), Physical Model Testing of Compaction Grouting in Cohesionless Soil, Journal of Geotechnical and Geoenvironmental Engineering, Vol.126, No.9, pp.848-852. https://doi.org/10.1061/(ASCE)1090-0241(2000)126:9(848)
  10. Santamarina, J. C., Klein, K. A., and Fam, M. A. (2001), Soils and waves. New York: J. Wiley & Sons.
  11. Wang, S., Chan, D., and Lam, K. C. (2009), Experimental Study of the Effect of Fines Content on Dynamic Compaction Grouting in Completely Decomposed Granite of Hong Kong, Construction and Building Materials, Vol.23, No.3, pp.1249-1264. https://doi.org/10.1016/j.conbuildmat.2008.08.002
  12. Wang, D., Xing, X., Qu, H., and Zhang, L. M. (2015), Simulated Radial Expansion and Heave Caused by Compaction Grouting in Noncohesive Soils, International Journal of Geomechanics, Vol.15, No.4, 04014069. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000333
  13. Wong, H. Y. (1971), "Compaction of Soil during Pressure Grouting", Private Rep.
  14. Wong, H. Y. (1974), Discussion of 'Compaction grouting', J. Geotech. Engrg. Div, Vol.100, No.5, pp.556-559. https://doi.org/10.1061/AJGEB6.0000049