A new simplified Hypothesis B method for calculating the consolidation settlement of ground improved by vertical drains

Wei Qiang Feng, Jianhua Yin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

Vertical drains are widely used in soft ground improvements to accelerate the consolidation process. This paper develops a new simplified Hypothesis B method for calculating the consolidation settlement of a soil layer improved by vertical drains under the instant and ramp loadings. As a comparison, the traditional Hypothesis A method is also used to calculate the settlement. Then, a fully coupled finite element consolidation analysis is utilized to examine and verify this simplified method and Hypothesis A method. For the instant loading, Carrillo-Barron method and Zhu-Yin method are used to obtain the average degree of consolidation for vertical drain system. Typical parameters, such as over-consolidation ratio (OCR), smear zone, and space ratio of vertical drains, are considered. It is found that the calculation results from the new simplified method in this study agree well with finite element simulations, and relative errors are in the range of 0.1% to 12.3%. Comparatively, there are obvious differences between the calculated results from Hypothesis A method and finite element results. Carrillo-Olson method and Zhu-Yin method are utilized to obtain the average degree of consolidation for the vertical drain system to consider the ramp loading. Equivalent time is determined from half of the construction period to calculate the creep compression under the ramp loading. The accuracy of this simplified Hypothesis B method using both Carrillo-Olson method and Zhu-Yin method is acceptable with the relative errors less than 9.4%.
Original languageEnglish
Pages (from-to)295-311
Number of pages17
JournalInternational Journal for Numerical and Analytical Methods in Geomechanics
Volume42
Issue number2
DOIs
Publication statusPublished - 1 Jan 2018

Keywords

  • consolidation settlement
  • creep
  • Hypothesis B
  • ramp loading
  • simplified method
  • vertical drain

ASJC Scopus subject areas

  • Computational Mechanics
  • Materials Science(all)
  • Geotechnical Engineering and Engineering Geology
  • Mechanics of Materials

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