A Servo/Suction-Controlled Ring Shear Apparatus for Unsaturated Soils: Development, Performance, and Preliminary Results

Most geotechnical infrastructure made of compacted soil, or resting on unsaturated ground, involves a wide range of deformations. However, few studies have investigated unsaturated soil behavior under large deformations while being subjected to controlled-suction states. In this paper, a fully servo/suction-controlled ring shear apparatus is introduced that has been made suitable for testing unsaturated soils at large deformations via axis-translation technique. The full development of the apparatus is outlined, including details of its main components, assembling, and performance verification against the original Bromhead device. A preliminary series of suction-controlled ring shear tests was conducted on several statically compacted samples of silty sand. Results showed that the residual friction angle with respect to matric suction remained virtually constant, regardless of the applied level of net normal stress. The findings from this study indicate that a conceptual residual shear strength framework for unsaturated soils, similar to that postulated for peak shear strength, is possible. Future refinements and testing of the proposed ring shear apparatus are planned.

• Record URL:
  • https://doi.org/ 10.1520/GTJ103598
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01496115
• Authors:
  • Hoyos, Laureano R
  • Velosa, Claudia L
  • Puppala, Anand J
• Publication Date: 2011-9

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 413-423
• Serial:
  • Geotechnical Testing Journal
  • Volume: 34
  • Issue Number: 5
  • Publisher: ASTM International
  • ISSN: 0149-6115
  • EISSN: 1945-7545
  • Serial URL: https://www.astm.org/products-services/standards-and-publications/geotechnical-testing-journal.html

Subject/Index Terms

• TRT Terms: Laboratory tests; Residual shear strength; Soil suction; Testing equipment; Unsaturated soils
• Uncontrolled Terms: Ring shear apparatus
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 01370999
• Record Type: Publication
• Files: TRIS
• Created Date: May 25 2012 9:31AM