Field measured and simulated performance of a stone columns-strengthened soft clay deposit

ABSTRACT

This paper described field behaviour of a stone columns-reinforced soft foundation at a coal and ore stockyard followed by a comparison with numerical analysis. Performance of a 130-m-wide section with two ore stacks was recorded along a 500-operative day. An extensive instrumentation, comprising 14 sensors, was used to monitor the serviceability behaviour of the stabilized area. Complementary numerical analysis was performed using PLAXIS 2D finite element code, with which the increase in lateral earth pressure due to column installation was suitably modeled. The numerical analysis was carried out using plane strain approach, in which the stone columns were converted into the equivalent walls. Results showed that the adopted plane strain model could predict well measured total deformations of the reinforced foundation. Simulated curves of excess pore pressure also showed similar behaviour to the field data with a maximum value upon loading application followed by a gradual dissipation in consolidation stages.

KEYWORDS:

• Soil improvement
• stone column
• field test
• soft soil
• field instrumentation
• in-situ testing
• numerical analysis

Acknowledgments

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001. The authors also thank Dr Marina Miranda and Dr Sunil Mohapatra for their suggestions to improve the quality of the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

List of symbols and abbreviations

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Additional information

Funding

This work was supported by the Brazilian National Funding Agency [1].

Notes on contributors

Bruno T. Lima

Bruno T. Lima has obtained his B.Sc. in Civil Engineering (2005) and M.Sc. in Geotechnical Engineering (2008) both from the State University of Rio de Janeiro, Brazil. He has also completed his Ph.D. in Geotechnical Engineering with the Graduate School in Research and Engineering (COPPE) at Federal University of Rio de Janeiro (UFRJ), Brazil, in 2012. He is currently Assistant Professor of Geotechnical Engineering at Rio de Janeiro State University and Federal Fluminense University. His research interests mainly focus on soft clay engineering, ground treatment, embankment design and analysis and numerical analysis.

Marcio S.S. Almeida

Marcio S.S. Almeida earned his Civil Engineering degree at UFRJ, Brazil, in 1974 and obtained his M.Sc. at COPPE of UFRJ, Brazil, in 1977. He obtained his Ph.D. from the University of Cambridge, UK in 1984. Then he returned to UFRJ and in 1994 became Professor of Geotechnical Engineering. His postdoc was at Italy ISMES and NGI, Norway in the early 1990s. He has published around 300 technical publications including more than 70 articles in international refereed journals and has supervised around 90 doctoral and master dissertations. He received the Terzaghi and José Machado awards from ABMS. He has served on the editorial board of Géotechnique, Géotechnique Letters, ICE-Ground Improvement and International Journal of Physical Modelling, among others. His main topics of interest are (1) soft clay engineering, (2) ground improvement, (3) marine geotechnics and (4) physical modeling.

Iman Hosseinpour

Iman Hosseinpourobtained his B.Sc. degree in Civil Engineering and M.Sc. degree in Geotechnical Engineering from Babol Noshirvani University of Technology, Iran, in 2005 and 2008, respectively, and his Ph.D. in Geotechnical Engineering from the Graduate School in Research and Engineering (COPPE) at Federal University of Rio de Janeiro (UFRJ), Brazil, in 2015. He has also completed two years postdoc fellowship at COPPE/UFRJ. Soon after that, he has joined the Civil Engineering Department at the University Guilan, Iran, as an Assistant Professor. He is the recipient of the Brazilian best doctoral thesis as well as the outstanding research awards by the Brazilian Association of Geotechnical Engineering (ABMS). He is also given the best paper award by Institution of Civil Engineers (ICE), UK in 2016. His research interests include (1) experimental geotechnics, (2) soft soil en-gineering, (3) piled foundation, (4) ground improvement and geosynthetics as well as (5) numerical analyses.