15th International Conference on Soil Mechanics and Geotechnical Engineering, İstanbul, Turkey, 27 - 31 August 2001, pp.275-278
Secondary compression is more significant in consolidation of high plasticity clays and peats. The effect of the various specimen heights on the secondary compression is examined in laboratory tests. The coefficient of C-alpha is determined for various specimen heights. A new oedometer cell is designed to measure pore pressures at the undrained base of the specimen and the friction between the ring and specimen. The side friction does not remain constant during the test and slightly increased with time (at a decreasing rate). The amount of the side friction depends upon the level of the applied vertical consolidation pressure on the specimen. Friction is found significant at low stresses when the clay was still over-consolidated. It is also observed that friction occurring between the specimen and ring is connected with the pore pressure dissipation. The development of friction largely ceases once the pore pressure dissipation is complete.