Thank you so much for your interest on my research. the equipment will be triaxial testing apparatus equiped with saturated ceramic disc to control the suction

The best I know is the frictionless triaxial apparatus. Great care must be taken to ensure water tight condition and preserving of water stiffness.

In undrained condition, water stiffness plays a big role. Water has a bulk stiffness of approximately 4GPa, thus even microscopic leaks (changes in void volume) are important. Even osmosis through a membrane, losing just a few molecules of water, could be detectable if water stiffness is preserved well (thus, we ended up using 2 membranes with a layer of vacuum grease in between, when testing undrained response).

Sadly, a lot of equipment uses soft tubes. This compromises undrained pore water stiffness, thus compromising measurements of pressure effects. If tubes are soft, a small volume of water can move in and out of the tube without being visible in measurements...

Also, the classical triaxial apparatus does not produce uniform volumetric response across the specimen. In classical setup, part of the specimen can be contracting, while another part is dilating, thus canceling each other out. Such measurements can be misleading and lead to false conclusions. Only the frictionless triaxial apparatus is capable of creating near isotropic stress / strain field within a specimen, to my knowledge.