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Numerical analysis of consolidation of soft soils fully-penetrated by deep-mixed columns

  • Research Paper
  • Geotechnical Engineering
  • Published:
KSCE Journal of Civil Engineering Aims and scope

Abstract

Deep mixing is a common ground improvement technology that can be used to increase bearing capacity and stability and reduce total and differential settlements of foundations constructed on soft soils. Field data have shown that deep mixed column foundations had a higher consolidation rate than untreated foundations even though deep mixed columns had similar or lower permeability than untreated soils. The consolidation mechanisms and behavior of deep mixed column foundations have not been well understood. In this study, the consolidation of soft soils fully penetrated by deep mixed columns was investigated using a mechanically and hydraulically coupled three-dimensional finite element method. One quarter of a unit cell was used considering its symmetry and the column and the surrounding soil were modeled as elastic materials. A case study for a stone column foundation in the literature was first used to verify the numerical model and then this model was adopted to analyze the stress transfer, settlement, and consolidation of the soft soil fully penetrated by a deep mixed column. A parametric study was conducted to evaluate the influence of four key factors, soft soil thickness, area replacement ratio, column modulus, and column permeability, on the stress concentration ratio (the ratio of the average vertical stress on the column to that on the soil), settlement, and average degree of consolidation of the deep mixed column foundation. The numerical results show that the average degree of consolidation calculated based on the settlement or the excess pore water pressure was identical. The stress concentration ratio increased with the column modulus and time, but the effect of the soft soil thickness, area replacement ratio, and column permeability was not significant. The simplified method based on a composite foundation concept could conservatively estimate the consolidation settlement. An increase of the column modulus, area replacement ratio, and/or column permeability increased the rate of consolidation.

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References

  • Alamgir, M., Miura, N., Poorooshasb, H. B., and Madhav, M. R. (1996). “Deformation analysis of soft ground reinforced by columnar inclusions.” Computers and Geotechnics, Vol. 18, No. 4, pp. 267–290.

    Article  Google Scholar 

  • Barksdale, R. D. and Bachus, R. C. (1983). Design and construction of stone columns, Federal Highway Administration, RD-83/026.

  • Broms, B. B. (1999). “The design of lime, lime/cement and cement columns.” Proc., International Conference on Deep Mix Method for Deep Soil Stabilisation, Stockholm, Sweden, pp. 125–153.

  • Bruce, D. A. (2001). An introduction to the deep mixing methods as used in geotechnical applications — Volume III: The Verification and Properties of Treated Ground. FHWA-RD-99-167, p. 455.

  • Chai, J. C., Miura, N., Kirekawa, T., and Hino, T. (2010). “Settlement prediction for soft ground improved by columns.” Ground Improvement, Vol. 163, No. G12, pp. 109–119.

    Article  Google Scholar 

  • Chai, J. C. and Pongsivasathit, S. (2009). “Prediction of consolidation settlements of floating column improved soft clayed subsoil.” Proceedings of International Symposium on Geotechnical Engineering, Ground Improvement and Geosynthetic for Sustainable Mitigation and Adaptation to Climate Change including Global Warming, Bangkok, Thailand, pp. 107–115.

    Google Scholar 

  • Chai, J. C., Shen, S. L., Miura, N., and Bergado, D. T. (2001). “Simple method of modeling PVD improved subsoil.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 127, No. 11, pp. 965–972.

    Article  Google Scholar 

  • Chew, S. H., Kamruzzaman, A. H. M., and Lee, F. H. (2004). “Physicochemical and engineering behavior of cement treated clays.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 130, No. 7, pp. 696–706.

    Article  Google Scholar 

  • Han, J., Chen, J. F., Hong, Z. S., and Shen, S. L. (2010). “Mitigation of levee failure using deep mixed columns and geosynthetics.” Geo-Mechanics and GeoEngineering: International Journal, Vol. 5, No. 1, pp. 49–55.

    Article  Google Scholar 

  • Han, J. and Gabr, M. A. (2002). “Numerical analysis of geosyntheticreinforced and pile-supported earth platforms over soft soil.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 128, No. 1, pp. 44–53.

    Article  Google Scholar 

  • Han, J., Parsons, R. J., Sheth, A. R., and Huang, J. (2005). “Factors of safety against deep-seated failure of embankments over deep mixed columns.” Proceedings of Deep Mixing 2005 Conference, Sweden, Vol. 1.2, pp. 231–236.

    Google Scholar 

  • Han, J., Yang, X. M., Chen, J. F., and Porbaha, A. (2009). “Settlement calculation of deep mixed foundations.” Proceedings of International Symposium on Deep Mixing and Admixture Stabilization, Okinawa, Japan, pp. 19–21.

  • Han, J. and Ye, S. L. (2001). “Simplified method for computing consolidation rate of stone column reinforced foundations.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 127, No. 7, pp. 597–603.

    Article  Google Scholar 

  • Han, J. and Ye, S. L. (2002). “A theoretical solution for consolidation rates of stone column-reinforced foundations accounting for smear and well resistance effects.” International Journal of Geomechanics, Vol. 2, No. 2, pp. 135–151.

    Article  Google Scholar 

  • Han, J., Zhou, H. T., and Ye, F. (2002). “State of practice review of deep soil mixing techniques in China.” Journal of the Transportation Research Board, Soil Mechanics 2002, Transportation Research Board of the National Academies, 1808, pp. 49–57.

  • Huang, J. and Han, J. (2009). “Three-dimensional coupled mechanical and hydraulic modeling of a constructed geosynthetic-reinforced column-supported embankment.” Geotextiles and Geomembranes, Vol. 27, No. 4, pp. 272–280.

    Article  Google Scholar 

  • Huang, J., Han. J., and Oztoprak, S. (2009). “Coupled mechanical and hydraulic modeling of geosynthetic-reinforced column-supported embankments.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 135, No. 8, pp. 1011–1021.

    Article  Google Scholar 

  • Jamsawang, P., Bergado, D. T., Bhandari, A., and Voottipruex, P. (2009). “Behavior of stiffened deep cement mixing pile in laboratory.” Lowland Technology International, Vol. 11, No. 1, pp. 20–28.

    Google Scholar 

  • Kitazume, M., Okano, K., and Miyajima, S. (2000). “Centrifuge model tests on failure envelope of column type deep mixing method improved ground.” Soils and Foundations, Vol. 40, No. 4, pp. 43–55.

    Article  Google Scholar 

  • Lorenzo, G. A. and Bergado, D. T. (2003). “New consolidation equation for soil-cement piles improved ground.” Canadian Geotechnical Journal, Vol. 40, No. 2, pp. 265–275.

    Article  Google Scholar 

  • Lorenzo, G. A. and Bergado, D. T. (2004). “Fundamental parameters of cement-admixed clay-New approach.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 130, No. 10, pp. 1042–1050.

    Article  Google Scholar 

  • Lorenzo, G. A. and Bergado, D. T. (2006). “Fundamental characteristics of cement-admixed clay in deep mixing.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 18, No. 2, pp. 161–174.

    Google Scholar 

  • Mayne, P. and Poulos, H. G. (1999). “Approximate displacement influence factor or elastic shallow foundations.” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 125, No. 6, pp. 453–460.

    Article  Google Scholar 

  • Miao, L., Wang, X., and Kavazanjian, E. (2008). “Consolidation of a double layered compressible foundation partially penetrated by deep mixed column.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 134, No. 8, pp. 1210–1204.

    Article  Google Scholar 

  • Navin, M. P. and Filz, G. M. (2006). “Numerical stability analysis of embankments supported on deep mixed columns.” Proceedings of GeoShanghai International Conference, ASCE Geotechnical Special Publication, Ground Modification and Seismic Mitigation, pp. 1–8.

  • Porbaha, A., Shibuya, S., and Kishida, T. (2000). “State of the art in deep mixing technology: Part III. Geomaterial characterization.” Ground Improvement, Vol. 4, No. 3, pp. 91–110.

    Article  Google Scholar 

  • Shen, S. L., Han, J., and Miura, N. (2004). “Laboratory evaluation of mixing energy consumption and its influence on soil-cement strength.” Journal of Transportation Research Board, Transportation Research Board of the National Academies, 1868, pp. 23–30.

  • Smith, M. and Filz, G. (2007). “Axisymmetric numerical modeling of a unit cell in geosynthetic-reinforced, column-supported embankments.” Geosynthetics International, Vol. 14, No. 1, pp. 13–22.

    Article  Google Scholar 

  • Tan, S. A., Tjahyono, S., and Oo, K. K. (2008). “Simplified plane-strain modeling of stone-column reinforced ground.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 134, No. 2, pp. 185–194.

    Article  Google Scholar 

  • Terashi, M. (2002). “The state of practice in deep mixing methods.” Grouting and Ground Treatment, Johnsen, L. F., Bruce, D. A., and Byle, M. J. (eds.), ASCE Geotechnical Special Publication No. 120, Vol. 1, pp. 25–49.

  • Terashi, M. and Tanaka, H. (1983). “Settlement analysis for deep mixing method.” Proceedings of the 10th Int. Conf. on Soil Mechanics and Foundation Engineering, Stockholm, Sweden, Vol. 3, pp. 777–780.

    Google Scholar 

  • Zheng, G., Liu, S.-Y., and Chen, R.-P. (2009). “State of advancement of column-type reinforcement element and its application in China.” Proceedings of the US-China Workshop on Ground Improvement Technologies, Advances in Ground Improvement, Geotechnical Special Publication No. 188, Han, J., Zheng, G., Schaefer, V. R., and Huang, M. S. (eds.) March 14, Orlando, Florida, pp. 12–25.

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Authors and Affiliations

  1. CCCC Highway Consultants Co., Ltd., Beijing, 100088, China

    Yan Jiang

  2. Dept. of Civil, Environmental & Architectural Engineering (CEAE), The University of Kansas, Lawrence, KS 66045, USA

    Jie Han

  3. Key Laboratory of Coastal Civil Engineering Structures and Safety, Tianjin University, Tianjin, 300072, China

    Gang Zheng

Authors
  1. Yan Jiang
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  2. Jie Han
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  3. Gang Zheng
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Correspondence to Jie Han.

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Jiang, Y., Han, J. & Zheng, G. Numerical analysis of consolidation of soft soils fully-penetrated by deep-mixed columns. KSCE J Civ Eng 17, 96–105 (2013). https://doi.org/10.1007/s12205-013-1641-x

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  • DOI: https://doi.org/10.1007/s12205-013-1641-x

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