ANALYTICAL AND MODEL STUDIES OF REINFORCEMENT OF A LAYER OF GRANULAR FILL ON A SOFT CLAY SUBGRADE

The effectiveness of geogrid reinforcement, placed at the base of a layer of granular fill on the surface of soft clay, has been studied by small-scale model tests in the laboratory. In the tests, monotonic loading was applied by a rigid footing, under plane strain conditions, to the surface of reinforced and unreinforced systems, using a range of fill thickness and subgrade strengths. Continuous measuremens were made of footing load and footing displacement, and deformations of the subgrade and of the geogrid reinforcement were measured from photographs. From these measurements the different mechanisms of failure in the unreinforced and reinforced system were established. Performance of reinforced systems was found to be superior even at small deformations, owing to the significant change in the pattern of shear forces acing on the surface of the clay, brought about by the presence of the reinforcement. Membrane action of the reinforcement only became significant at large deformations. A finite element computer program has been specially formulated to allow inclusion of a thin reinforcing layer, and to handle correctly the large deformations and strains induced in the physical models. This formulation is able to reproduce satisfactorily the main features of behaviour observed in the models, and may be used with some confidence to perform accurate predictions for full-scale structures.

• Corporate Authors:

  National Research Council of Canada

  1200 Montreal Road
  Ottawa, Ontario  Canada  K1A 0R6
• Authors:
  • LOVE, J P
  • BURD, H J
  • MILLIGAN, GWE
  • Houlsby, G T
• Publication Date: 1987-11

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 611-622
• Serial:
  • CANADIAN GEOTECHNICAL JOURNAL
  • Volume: 24
  • Issue Number: 4
  • Publisher: National Research Council of Canada

Subject/Index Terms

• TRT Terms: Bearing capacity; Clay; Computer programs; Deformation; Failure; Fills; Finite element method; Flexibility; Forecasting; Foundations; Geogrids; Geotextiles; Granular materials; Mathematical models; Shear strength; Soft clays; Stiffness; Subgrade (Pavements); Surface course (Pavements); Swamps
• Uncontrolled Terms: Models; Rigid foundations
• Old TRIS Terms: Control conditions; Finite elements; Flexible surfacings
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00469039
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 30 1988 12:00AM