Kazutoshi Hirao

Undrained Shear Behaviour of Quasi-overconsolidated Seabed Clay Induced by Cyclic Loading

Seabed soil lying at shallow depth sometimes exhibits abnormal geotechnical and geological behaviour, particularly with regard to the void ratio—effective overburden pressure—undrained strength relation. This behaviour may possibly be connected with the cyclic loading induced by wind and wave forces acting on the seabed. The authors have considered the seabed in this circumstance as quasi-overconsolidated soil, the behaviour of which is assumed to be equivalent to that of overconsolidated soil due to release of overburden pressure. That is, for predicting the undrained strength of quasi-overconsolidated clay, the authors employ the simple relation which holds good between the over-consolidated clay due to release of effective stress and normally consolidated clay.