ISSN: 2734-9438
Website: www.jomc.vn
Numerical Study on the Settlement of Soft Soil Reinforced by Soil-Cement Columns comparing to Viet Nam standard - A Case Study in Can Tho, Vietnam
Abstract
Soft clay in the Mekong Delta often settles too much under road embankments. This paper studies how the main geometric factors of soil–cement columns (SCCs)—column length and spacing—change the settlement. Forty-two 2D PLAXIS models were run for four lengths (8, 10, 12, 14 m) and nine spacing ratios (Sc/D = 2.0–4.0, column diameter 0.8 m). For the block ground reinforced by SCC, the calculated settlements were compared with Vietnamese standards TCVN 9403:2012 values and TCCS 41:2022. The results show three clear trends. First, short columns (8 m) give large settlement that grows quickly as spacing widens, while columns 12 m or longer make settlements almost constant for the same spacing range. Second, an economical spacing ratio of Sc/D is from 2.0 to 2.5. Third, the code method is inconsistent: it underestimates settlement for tight grids but overestimates it for long columns with wide grids. The study concludes that 12 m SCCs spaced at 2.0D –3.0D give deltaic clay the best balance between cost and performance. Wider grids or deeper columns should be checked with finite-element analysis to avoid unsafe or overly conservative designs.
References
- Institute of Science and Technology, Ministry of Construction, TCVN 9403:2012—Ground Improvement for Soft Soils: Soil–Cement Columns, Hanoi, Viet Nam: Ministry of Science and Technology, 2012.
- C. Ma and B. Chen, “Analysis of strength development in soft clay stabilized with cement-based stabilizer,” Construction and Building Materials, vol. 71, pp. 354–362, Aug. 2014, doi: 10.1016/j.conbuildmat.2014.08.087.
- D. T. Bergado, T. Ruenkrairergsa, Y. Taesiri, and A. S. Balasubramaniam, “Deep soil mixing used to reduce embankment settlement,” Proceedings of the Institution of Civil Engineers – Ground Improvement, vol. 3, no. 4, pp. 145–162, 1999, doi: 10.1680/gi.1999.030402.
- P. J. V. Oliveira, J. L. Pinheiro, and A. A. S. Correia, “Numerical analysis of an embankment built on soft soil reinforced with deep-mixing columns: parametric study,” Computers and Geotechnics, vol. 38, no. 4, pp. 566–576, Mar. 2011, doi: 10.1016/j.compgeo.2011.03.005.
- K. G. Prakash and A. Krishnamoorthy, “Stability of embankment constructed on soft soil treated with soil–cement columns,” Transportation Infrastructure Geotechnology, vol. 10, no. 4, pp. 595–615, 2022, doi: 10.1007/s40515-022-00237-3.
- B. B. Broms, “Design of lime, lime/cement and cement columns,” in Dry Mix Methods for Deep Soil Stabilization, 1st ed., London, U.K.: Routledge, 2009, ch. 17, pp. 471–508, doi: 10.1201/9781315141466-17.
- A. Wang, D. Zhang, and Y. Deng, “Lateral response of single piles in cement-improved soil: numerical and theoretical investigation,” Computers and Geotechnics, vol. 102, pp. 164–178, Sep. 2018, doi: 10.1016/j.compgeo.2018.06.014.
- O. Novytskyi, “Soil-cement piles fibre-reinforced: theory and building practice,” Journal of Theory and Building Practice, vol. 3, no. 1, pp. 113–119, 2021, doi: 10.23939/jtbp2021.01.113.
- N. Seregin, “An integrated way to improve the properties of soil-cement pile foundations,” E3S Web of Conferences, vol. 157, art. 06006, 2020, doi: 10.1051/e3sconf/202015706006.
- W. D. Meyersohn, “Use of soil-cement piles for bridge support,” in Contemporary Issues in Deep Foundations, Reston, VA, USA: ASCE, 2007, pp. 1–10, doi: 10.1061/40902(221)17.
- Đ. H. Dao, P. M. Tuan, and P. C. Tho, “Effect of key parameters on embankment foundations using cement-treated soil columns reinforced with geotextile,” Journal of Science and Technology – University of Danang, vol. 9, no. 82, pp. 5–9, Sep. 2014. Available at https://jst-ud.vn/jst-ud/article/view/836.
- M. Bolton, J. Noonan, and E. Oh, “Effect of soil-cement column spacing and area-replacement ratio on embankment bearing capacity: a Queensland case study,” International Journal of Geomate, vol. 11, no. 26, pp. 2589–2594, 2016. Available at https://geomatejournal.com/geomate/article/view/2638
- N. H. Thien and L. B. Vinh, “Application of PLAXIS 2D to analyse consolidation of soft ground improved by soil–cement columns under embankment loads,” Journal of Science – Ho Chi Minh City Open University, vol. 12, no. 1, pp. 3–11, 2017. Available at https://vjol.info.vn/index.php/DHM-KTCN/article/view/56227
- N. T. N. Yen and T. T. Viet, “Influence of geometric parameters of soil–cement columns on stability of embankments on soft soils,” Journal of Water Resources and Environmental Engineering, vol. 68, no. 3, pp. 10–18, 2020. Available at https://vjol.info.vn/index.php/DHTL/article/view/48692
- L. B. Quoc and P. Q. Vinh, “Use of soil–cement columns in civil construction in Dong Thap Province,” Journal of Science and Technology – Western Construction University, no. 1, pp. 9–18, 2022. Available at https://vjol.info.vn/index.php/mtu/article/view/93379/78927
- T. N. N. Thang and N. A. Tuan, “Soft ground improvement below bridge approaches using cement deep-mixing columns combined with geotextile,” Journal of Applied Engineering Science, vol. 21, 2023, doi: 10.5937/jaes0-40629.
- L. B. Vinh, “Model tests on settlement behaviour of soft ground improved by soil–cement columns,” Journal of Water Science and Technology, no. 26, pp. 1–10, 2015. Available at http://www.vawr.org.vn/images/File/TS.%20Le%20Ba%20Vinh.pdf
- Q. Y. Pan, K. H. Xie, Y. L. Liu, and Q. Lin, “Some aspects of soft ground improved with cement columns,” in Proceedings of the 13th International Conference on Soil Mechanics and Foundation Engineering, New Delhi, India, 1994, pp. 1223–1226.
- S. Baker, N. S. D. Liedberg, and G. Sällfors, “Deformation properties of lime–cement stabilised soil in the working state,” in Proceedings of the 14th International Conference on Soil Mechanics and Foundation Engineering, Hamburg, Germany, 1997, vol. 3, pp. 1667–1672.
- J. C. Chai, N. Miura, T. Kirekawa, and T. Hino, “Settlement prediction for soft ground improved by columns,” Proceedings of the Institution of Civil Engineers – Ground Improvement, vol. 163, no. 2, pp. 109–119, 2010, doi: 10.1680/grim.2010.163.2.109.
- S. Pongsivasathit, J. C. Chai, and W. Ding, “Consolidation settlement of floating-column-improved soft clayey deposit,” Proceedings of the Institution of Civil Engineers – Ground Improvement, vol. 166, no. 1, pp. 44–58, 2013, doi: 10.1680/grim.11.00028.
- J. C. Chai, S. Liu, and Y. Du, “Field properties and settlement calculation of soil–cement column–improved soft subsoil: A case study,” Lowland Technology International, vol. 4, no. 2, pp. 51–58, 2002. Retrieved from https://cot.unhas.ac.id/journals/index.php/ialt_lti/article/view/307
- J. Han, J. Huang, and A. Porbaha, “Two-dimensional numerical modelling of a geosynthetic-reinforced embankment over deep-mixed columns,” in Contemporary Issues in Foundation Engineering, Reston, VA, USA: ASCE, 2005, pp. 1–11, doi: 10.1061/40777(156)13.
- N. Yapage et al., “Numerical modelling of geotextile-reinforced embankments over deep cement-mixed columns incorporating strain-softening behaviour of columns,” International Journal of Geomechanics, vol. 15, no. 2, 2015, doi: 10.1061/(ASCE)GM.1943-5622.0000341.
- Ministry of Transport, TCCS 41:2022 – Specification for Survey and Design of Highway Embankment on Soft Ground, Hanoi, Viet Nam, 2022.

