The test consists of placing a rock cylinder specimen in a triaxial cell. The specimen is subjected to a constant lateral stress (confinement) for the duration of the test, and subjected to an increasing axial stress until the sample's failure. The triaxial compressive strength of rocks is generally influenced by their water content. The tests can be carried out:either on samples in the state in which they are taken, either on previously dried samples, or on previously saturated samples.