A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering at the Asian Institute of Technology, Bangkok, Thailand.

Thesis (M.Eng.) - Asian Institute of Technology, 1972

An experimental investigation was carried out to study the effects of anisotropic preconsolidation on the strength characteristics of three artificially sedimented, normally consolidated clays. Sediments of Soft Bangkok Clay in the three different solutions of calcium chloride, sodium chloride and distilled water were preconsolidated under Ko conditions by vertical pressures ranging from 10 to 80 lb/ in2 before isotropic CU triaxial tests were carried out. The experimental evidence collected from this short investigation is conclusive in proving that the existing laboratory triaxial technique does not give unique strength behaviour for a particular normally consolidated clay. It is clear that the strength characteristics, as determined from specimens consolidated isotropically in the .triaxial cell, are affected by the anisotropic stress conditions imposed on the clay prior to sampling where the laboratory consolidation pressure is considerably higher than the maximum past pressure, the effects of the prior anisotropic consolidation is not important. These effects are only significant where Ō vm is small and where Ōc/Ōvm approaches unity. This conclusion appears to be independent of the structure produced in the clay by the process of sedimentation.