Akio Nakase

Centrifuge Modeling of River Bank Failures Due to Seepage Flow

A series of centrifuge model tests was carried out in an attempt to study river bank failures due to seepage flow. The necessity of centrifuge modeling and the similarity law were discussed. The results of the model tests showed that capillary tension above phreatic surface plays an important role in stability, and that there seems to exist a critical value of velocity of fluid flow to trigger an initial failure. An analytical model to simulate the development of failure was also proposed.

In situ Void Ratio, Strength and Overburden Pressure Anomalies in Seabed Clays

Seabed clays are said, in general, to be in an apparently overconsolidated state due to ageing effects. Mostly the in situ relationship between effective overburden pressure p, void ratio e and undrained shear strength c u, has been considered not much different from that in normally consolidated young clays, i.e. c u increases and e decreases with depth.