Evaluation of the Low Replacement Reinforced Ground Using Laboratory Tests

실내시험을 이용한 저치환 보강지반의 평가

  • Bae, Woo-Seok (Department of Civil and Environmental Engineering, Cheongju University)
  • 배우석 (청주대학교 이공대학 토목환경공학과)
  • Published : 2008.12.31

Abstract

SCP(Sand Compaction Pile) method that forms a composite ground by driving compacted sand piles into the soft ground. This method is one of the soil improvement techniques for reinforcing and strengthening soft ground deposits. This thesis describes the investigation on the behavior of soft ground reinforced with SCP by low improvement ratio. Direct shear test and consolidation test carried out to verified behavior of composite ground reinforced with SCP. Test results were discussed with reference to the amount of consolidation settlement, variation of shear resistance with area replacement ratio and effect of the stress concentration. And, laboratory model loading test carried out to verified the effect of the location and failure mode of reinforced embankment. Residual shear strength varies with the area replacement and constrict load in the low replacement ratio. Calculated stress concentration ratio overestimate than proposed valve by experimental, theoretical and analytical method. As regards the location, improving right below of the top of the slope was more effective than below of the toe of the slope. This thesis carried out to obtain fundamental information of behavior of the composit ground. Hereafter, centrifuge test that reproduce stress state of the in-situ must be necessary through the further study about pile penetration, reinforce position and construct time.

References

  1. Murayama, S., "Improvement of Soft Ground by Sand Compaction Piles", Conference Papers of Osaka Construction Works, No. 150, pp. 1-17, 1957
  2. Ibaraki, T., "An Experimental Research of Composite ground by direct shear test", Tsuchi to Kiso, Vol. 13, pp. 33-39, 1965
  3. Yamaguchi, h. and Murakami, Y., "On Stress Distribution of Composite Ground", The 11th Conference of JSSMFE, pp. 543-546, 1977
  4. Shinsha, H., Takata, K., Kurumada, Y., and Fuji, N., "Centrifuge Model Tests on Clay Ground Partly Improved by S.C.P", Centrifuge 91, Rotterdam, pp. 311-318, 1991
  5. 장신남, 박용원, 김병일, "모래다짐말뚝 시공 지반의 사면안정해석", 한국지반공학회 가을 학술발표회 논문집, pp. 89-96, 1997
  6. 배우석, 오세욱, 신방웅, "모래다짐말뚝으로 개량된 복합지반의 거동에 관한 원심모형실험-응력집중을 중심으로-", 대한토목학회 논문집, Vol.26 No.1C, pp. 19-24, 2006