Investigation of strength properties and specific strain energy of rocks under triaxial compression

One of the most demanded types of testing rock samples nowadays is triaxial compression. It helps to recreate in laboratory conditions various distributions of the main compressive stresses characteristic for a rock mass both in direction and magnitude. In this case, the most commonly used loading pattern is when the maximum component of the compressive stresses changes, while the intermediate and the minimum ones are equal to each other and remain constant during the test (a variant of triaxial axisymmetric compression). The paper presents the results of studies aimed at identifying the change patterns in the compressive strength of rocks and their specific strain energy under triaxial axisymmetric load. The results of tests on eight types of rocks from deposits in the Kola region have been analyzed. It is shown that in conditions of triaxial axisymmetric compression with increasing lateral pressure, the values of the compressive strength of the samples and their critical values of specific strain energy will also increase. The regularities of changes in the investigated rock characteristics with increasing lateral pressure have been established.И