The mechanisms by which a geogrid acts to reinforce a granular layer over a soft clay were investigated with reference to trafficking of unpaved roads. The research involved a programme of physical testing at both model and full scale. Model tests were carried out for monotonic and cyclic loading of a dual footing on to a layer of granular material that was compacted over a consolidated kaolin sample. The tests were made in conditions of plane strain at a quarter scale, and included a scaled geogrid at the base of the granular layer. Measurements of footing load, displacements and photographic observations through a perspex front face to the test box were used to identify the reinforcing actions of the geogrid. A virtual work procedure was adopted in analysis of the results for both unreinforced and reinforced layers. The procedure accounts for lateral restraint of the subgrade and a membrane action in the reinforced tests, and allows a comparison of the cyclic test results with an equivalent monotonic bearing capacity. Load tests were also made on footing plates at full scale, involving a similar arrangement of compacted granular layers over prepared London clay and including a high strength polymer geogrid. Examination of the test results allowed a qualitative assessment of the model performance and the reinforcing mechanisms attributed to the geogrid.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:376912 |
| Date | January 1986 |
| Creators | Fannin, Robin Jonathan |
| Contributors | Milligan, G. W. E. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:8c860a74-b730-4039-9d5f-383c4156257b |
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