Behavior of a compacted completely decomposed granite soil from suction controlled direct shear tests

Md Akhtar Hossain, Jianhua Yin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

66 Citations (Scopus)


A series of single-staged consolidated drained direct shear tests are carried out on recompacted completely decomposed granite (CDG) soil-a typical residual soil in Hong Kong, under different matric suctions and net normal stresses. Matric suction is controlled by applying air pressure in the pressure chamber and water pressure at the bottom of the high air-entry ceramic disk. The experimental results show that the contribution of suction to shear strength is significant. Shear strength of CDG soil increases with the increase of matric suction. Net normal stress has a remarkable influence on the shear strength of unsaturated CDG soil. The increase in shear strength due to an increase in matric suction (suction envelope) is observed as nonlinear i.e., φ{symbol}b value varies with matric suction. No soil dilatancy is observed for zero matric suction (saturated case) but as the suction value is increased, higher soil dilatancy is obvious in lower net normal stresses. The rate of increase of soil dilatancy is greater in lower suction range than in higher suction range. The experimental shear strength data match closely with the shear strength predicted by existing shear strength model considering the soil-dilation effect.
Original languageEnglish
Article number024001QGT
Pages (from-to)189-198
Number of pages10
JournalJournal of Geotechnical and Geoenvironmental Engineering
Issue number1
Publication statusPublished - 10 Feb 2010


  • Axis-translation technique
  • Completely decomposed granite
  • Dilatancy
  • Direct shear
  • Matric suction
  • Shear strength
  • Shear tests
  • Soil compaction
  • Soil dilatancy
  • Suction

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • General Environmental Science


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