Theoretical and experimental investigations have been carried out to study the influence of stress path on the deformation and consolidation of over-consolidated clays - with particular emphasis on London clay - in relation to settlement of structures. It is shown that for a proper understanding of the deformation of a soil beneath a foundation the soil should be tested in the laboratory under the same set of effective stresses that it will undergo in the field and that the influence of lateral stresses cannot be ignored. The stresses and displacements in non-homogeneous soil media, beneath circular and strip footings, have been calculated from Gibson's analytical solutions. A numerical method is suggested for determining the "immediate" (elastic) settlement of structures founded on a medium whose modulus of elasticity varies with depth. The influence of lateral stresses on the deformation characteristics of undisturbed London clay has been studied from both oedometer and triaxial tests while the stress path for one-dimensional compression is determined from specially designed oedometers. The effect of small pressure increments on the compressibility of London clay is also studied in the oedometer. The experimental results are examined in the light of their influence on the settlement of structures and a method of settlement analysis is proposed that takes into account the stress path of the elements of soil beneath a foundation: comparisons are made with the existing methods of analysis. The pre-consolidation pressures of London clay are determined from the stress deformation characteristics of samples loaded to high effective stresses.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:284294 |
| Date | January 1968 |
| Creators | Som, Nitindra-Nath |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/17732 |
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