ABSTRACT
The failure mechanism of landslide was investigated with pore water pressure loading test of a clay under the condition of constant deviator stress application. Through the test results, the followings were obtained: (1)Upper and lower yield limits in terms of effective stress were measured for generation of shear deformation. They could give the alternative design parameters. (2)Shear deformation of soil was found to proceed with water migration so that the phenomenon appeared slowly with time. As the effective stress passed the lower limit, shear deformation proceeded with longer time due to dilation behavior caused by plastic deformation. It showed the possible reason that the landslide developed with long time in a different way from the mudslide.
