Determining the Microcracks Closureand Opening with Different Loading Paths Triaxial Tests

This paper discusses a complex investigation to determine the microcrack closure and opening, with four different triaxial tests of a homogeneous isotropic limestone. Two of the researches were under drained conditions (deviatoric triaxial test and triaxial test with constantly increasing stress) and two of them were under undrained conditions (triaxial test connected with decreasing confining pressure and triaxial test with constantly increasing stress). During the tests the uniaxial and the confining pressure, the pore-fluid pressure, and the axial and the lateral strains were measured continuously