Keiichiro SAITO

Investigation of Time Dependent Behavior in Landslide with Pore Water Pressure Loading Tests

Satoru OHTSUKA


Pore water pressure loading test has two different meanings. One is an element test to investigate the soil behavior up to failure, and the other is the model test for landslide where the soil specimen is not uniform. This study used there different properties of pore water pressure loading tests and investigated (1)soil strength for repetitive pore water pressure loading, and (2)time dependent behavior as creep. The following conclusions were obtained in this study.
(1)Pore water pressure loading test was conducted on Nagaoka and Fujinomori clays. Change in yield and failure stresses for repetitive pore water pressure loading were investigated in the space of void ratio and effective mean stress.
(2)Time dependent behavior of pore water pressure loading test was clarified from the viewpoint of soil water coupling concept.
(3)Effective total stiffness was newly defined to express the stiffness of ground in terms of effective stress, based on continuum mechanics. Effective total stiffness was effective to investigate the deterioration of ground resistance to failure.
(4)Mechanism of creep behavior was considered with effective total stiffness.