Advertisement

An Elastic Visco-Plastic Model for Soft Soil with Reference to Radial Consolidation

  • Pankaj BaralEmail author
  • Buddhima Indraratna
  • Cholachat Rujikiatkamjorn
Conference paper
Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 29)

Abstract

The time-dependent stress–strain behaviour of soft soil due to its viscous nature affects its long-term settlement and pore water dissipation. A novel mathematical model developed using the Peaceman–Rachford ADI scheme (P–R FD Scheme) can describe the visco-plastic behaviour of soft clay with a non-Darcian flow function; this model is a combination of the basic radial consolidation equation developed by Barron and Bjerrum’s time-equivalent (Bjerrum in Geotechnique 17:81–118, 1967) concept that incorporates Yin and Graham’s (Can Geotech J 26:199–209, 1989b) visco-plastic parameters. The settlement and excess pore water pressure obtained from this model are then compared with preexisting models such as a Class C prediction for the Ballina trial embankment at National Field Testing Facility (NFTF). This elastic visco-plastic model provides better results in terms of settlement and pore water pressure with the field data, although the excess pore water pressure that did not dissipate after one year is mainly due to the piezometers becoming biologically and chemically clogged in terrain with acid sulphate soil (ASS).

Keywords

Visco-plastic Soft soil Peaceman–Rachford ADI Class C prediction 

Notes

Acknowledgements

The authors would like to thank the Centre of Geo-mechanics and Railway Engineering (CGRE), University of Wollongong, for providing a scholarship for the first authors’ Ph.D. study. The efforts of university technicians (Cameron Neilson, Ritchie Mclean, and Alan Grant) during fieldwork and laboratory setup are gratefully acknowledged, as is the dedication provided by Dr. Richard Kelly and Prof. Scott Sloan as they managed the Ballina trial embankment project.

References

  1. Bergado D, Anderson L, Miura N, Balasubramaniam A (1996) Soft ground improvement in lowland and other environments. ASCEGoogle Scholar
  2. Bjerrum L (1967) Engineering geology of Norwegian normally-consolidated marine clays as related to settlement of buildings. Geotechnique 17:81–118Google Scholar
  3. Chu J, Yan SW, Yang H (2000) Soil improvement by the vacuum preloading method for an oil storage station. Geotechnique 50:625–632CrossRefGoogle Scholar
  4. Degago SA, Grimstad G, Jostad HP, Nordal S, Olsson M (2011) Use and misuse of the isotache concept with respect to creep hypotheses a and b. Geotechnique 61:897–908CrossRefGoogle Scholar
  5. Hansbo S (1960) Consolidation of clay, with special reference to influence of vertical sand drains.Proc Swed Geotech Inst 18:160Google Scholar
  6. Indraratna B, Redana I (2000) Numerical modeling of vertical drains with smear and well resistance installed in soft clay. Can Geotech J 37:132–145CrossRefGoogle Scholar
  7. Indraratna B, Rujikiatkamjorn C, Kelly RB, Buys H (2012) Soft soil foundation improved by vacuum and surcharge loading. Proc Inst Civ Eng Ground Improv 165:87–96CrossRefGoogle Scholar
  8. Indraratna B, Baral P, Ameratung J, Kendaragama B (2017) Potential biological and chemical clogging of piezometer filters in acid sulphate soil. Aust Geomech J 52(2):79–85Google Scholar
  9. Indraratna B, Baral P, Rujikiatkamjorn C, Perera D (2018) Class A and C predictions for Ballina trial embankment with vertical drains using standard test data from industry and large diameter test specimens. Comput Geotech 93:232–246CrossRefGoogle Scholar
  10. Lambe TW (1973) Prediction in soil engineering. Geotechnique 23:149–202CrossRefGoogle Scholar
  11. Murray W, Lynn M (1965) A computer-oriented description of the Peaceman–Rachfordadi method. Comput J 8:166–175CrossRefGoogle Scholar
  12. Pineda J, Suwal L, Kelly R, Bates L, Sloan S (2016) Characterisation of Ballina clay. Géotechnique 66(7):556–577CrossRefGoogle Scholar
  13. Qu G, Hinchberger S, Lo K (2010) Evaluation of the viscous behaviour of clay using generalised overstress viscoplastic theory. Geotechnique 60:777–789CrossRefGoogle Scholar
  14. Yin JH, Graham J (1989a) General elastovisco plastic constitutive relationship for 1-d straining in clays. In: 3rd international symposium on numerical models in geomechanics, Niagara FallsGoogle Scholar
  15. Yin JH, Graham J (1989b) Viscous-elastic-plastic modelling of one dimensional time-dependent behaviour of clays. Can Geotech J 26:199–209CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Pankaj Baral
    • 1
    Email author
  • Buddhima Indraratna
    • 1
  • Cholachat Rujikiatkamjorn
    • 1
  1. 1.Faculty of Engineering and Science, School of Civil, Mining and Environmental EngineeringUniversity of WollongongWollongongAustralia

Personalised recommendations