Author : Jeong, Seon Hwan

Publication Date : july 2013

Key Word : Strength - Strain characteristic, Jumunjin sand, Triaxial test, Cyclic Triaxial, Stress path, Stress - Stain relationship

Abstract :

This study presents the stress–strain characteristics of sands. A series of static and cyclic triaxial tests of Jumunjin sands were carried out. The samples were made by controlling the relative density (i.e., 30%, 60%, 80%) and confining pressure (i.e., 100kPa, 200kPa, 300kPa) of sand.

In the case of static triaxial test under strain control state, it is controlled the shear strain up to 20% for compression test and the shear strain up to 10% for extension test. In the case of cyclic triaxial test under stress control state, it is controlled the shear strain up to 5%. The cyclic stress condition was achieved by controlling the ratio of confining pressure and cyclic stress (Cyclic Stress Ratio). The frequency of cyclic stress was 1Hz for the cyclic triaxial test.

It is found that the all different stress paths approach to the failure line (Kf line), irrespective of loading condition, drained condition, relative density. When the relative density of sample is higher than 60% in the static triaxial test, the volume dilation is pronounced and the negative pore water pressure was generated. It is also found that, the undrained behaviors of sands in compression and extension tests are similar, but at peak stress, the compression response is two times larger than the extension response.