Influence of Different Axis-Translation Technique Using Ceramic Disk /Microporous Membrane on Unsaturated Triaxial Test and Its Numerical Simulation

Abstract:

In this paper， an unsaturated triaxial test was conducted on Masado using axis-translation technique （ATT） with ceramic disk/microporous membrane filter （MM filter）. The stress-strain relation and drainage properties in the shear stage was obtained under the constant suction condition. Then， the finite element method （FEM） was utilized to simulate the triaxial test as a boundary value problem. The drained/vented triaxial tests results show that the degree of saturation and the drainage discharge of the specimen with the ATT of the MM filter is different from that of the ceramic disk. The calculated global stress-strain relation basically has a similar tendency as the triaxial test. The suction and the saturation are non-uniformly distributed within the specimen. The ATT with the MM filter is able to control the suction better during the shear stage than that with the ceramic disk. Thus， the unsaturated triaxial test with the ATT would be considered as a boundary value problem instead of an element test.