Constant water content direct shear testing of compacted residual soils

Üyetürk C. E., Huvaj N.

BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT, vol.80, no.1, pp.691-703, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 80 Issue: 1
  • Publication Date: 2021
  • Doi Number: 10.1007/s10064-020-01893-w
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, IBZ Online, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Communication Abstracts, Compendex, Environment Index, Geobase, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Page Numbers: pp.691-703
  • Keywords: Constant water content test, Direct shear test, Shear strength, Compacted soil, Unsaturated soil, STRENGTH
  • Middle East Technical University Affiliated: Yes


Mechanical behavior of residual soils are studied by performing constant water content direct shear tests on reconstituted specimens using total stress analysis. The testing program involves initial degree of saturation (Sr) and applied normal stress as the control parameters. For three different soil samples, a total of 55 direct shear tests are conducted at Sr = 60%, 80%, and saturated conditions, in the normal stress range of 15-60 kPa. The results showed that shear strength increases with decreasing Sr and the relationship between shear strength and Sr is nonlinear. More dilative response is observed with decreasing Sr and decreasing applied normal stress. Maximum dilatancy and Sr relationship is nonlinear. At large displacements, samples prepared at different Sr levels showed similar ultimate shear resistances under similar applied normal stresses. It is concluded that Sr and applied normal stress dramatically influence the mechanical behavior of compacted residual soils studied.