Unconsolidated undrained (UU) test is the most assured test to determine disturbed and undisturbed compression strength of soil properties. stress-strain relation of undisturbed soil specimen is investigated by subjecting the soil sample to different stress levels and drainage conditions.

In UU test, the specimens (assumed to be saturated prior to test and usually the height is double of diameter) are subjected to a confining fluid pressure in a Triaxial chamber. Once the specimen is inside the Triaxial cell, the cell pressure is increased to a predetermined value by rotating the knob, and the specimen is brought to failure by increasing the vertical stress by applying a constant rate of axial strain. These tests are generally carried out on three specimens of the same sample subjected to different confining stresses.